Added support for validation tests to DocTest.py (input:validate and

command:validate)

It is now possible to use @smallexample @c input:validate (and
command:validate) to specify that an example should just be read by
ledger (and checked for errors) or that a ledger command should be
executed (with default input -f sample.dat, if none is specified).

These annotations have been added into ledger3.texi where appropriate.

Running the ledger3.texi test now takes a second or two, but a lot of
the @smallexamples are now automatically tested.

2 files changed, 240 insertions, 177 deletions

diff --git a/doc/ledger3.texi b/doc/ledger3.texi
index cd9fbc59..d0b1ab54 100644
--- a/doc/ledger3.texi
+++ b/doc/ledger3.texi
@@ -291,7 +291,7 @@ finance programs use ``categories'', Ledger uses accounts. So, for
 example, if you buy some groceries at Trader Joe's then more groceries
 at Whole Foods Markets you might assign the transactions like this
 
-@smallexample
+@smallexample @c input:validate
 2011/03/15   Trader Joe's
     Expenses:Groceries   $100.00
     Assets:Checking
@@ -692,7 +692,7 @@ where the money comes from and where it goes to.  For example, when
 you are paid a salary, you must add money to your bank account and
 also subtract it from an income account:
 
-@smallexample
+@smallexample @c input:validate
 9/29  My Employer
     Assets:Checking                           $500.00
     Income:Salary                            $-500.00
@@ -831,7 +831,7 @@ This is fairly easy to do in ledger.  When spending the money, spend
 it @emph{to} your Assets:Reimbursements, using a different account for
 each person or business that you spend money for.  For example:
 
-@smallexample
+@smallexample @c input:validate
 2004/09/29  Circuit City
     Assets:Reimbursements:Company XYZ     $100.00
     Liabilities:MasterCard
@@ -842,7 +842,7 @@ expense was made on behalf of Company XYZ.  Later, when Company XYZ
 pays the amount back, the money will transfer from that reimbursement
 account back to a regular asset account:
 
-@smallexample
+@smallexample @c input:validate
 2004/09/29  Company XYZ
     Assets:Checking                       $100.00
     Assets:Reimbursements:Company XYZ
@@ -864,7 +864,7 @@ company accounts.  But keeping them in one file involves the same
 kinds of postings, so those are what is shown here.  First, the
 personal transaction, which shows the need for reimbursement:
 
-@smallexample
+@smallexample @c input:validate
 2004/09/29  Circuit City
     Assets:Reimbursements:Company XYZ     $100.00
     Liabilities:MasterCard
@@ -876,7 +876,7 @@ transaction should be immediately followed by an equivalent
 transaction, which shows the kind of expense, and also notes the fact
 that $100.00 is now payable to you:
 
-@smallexample
+@smallexample @c input:validate
 2004/09/29  Circuit City
     Company XYZ:Expenses:Computer:Software      $100.00
     Company XYZ:Accounts Payable:Your Name
@@ -889,7 +889,7 @@ paid back.
 These two transactions can also be merged, to make things a little
 clearer.  Note that all amounts must be specified now:
 
-@smallexample
+@smallexample @c input:validate
 2004/09/29  Circuit City
     Assets:Reimbursements:Company XYZ         $100.00
     Liabilities:MasterCard                   $-100.00
@@ -903,7 +903,7 @@ paying it to accounts payable, and then drawing it again from the
 reimbursement account, and paying it to your personal asset account.
 It's easier shown than said:
 
-@smallexample
+@smallexample @c input:validate
 2004/10/15  Company XYZ
     Assets:Checking                           $100.00
     Assets:Reimbursements:Company XYZ        $-100.00
@@ -1383,7 +1383,6 @@ list them as you would normally, for example:
     Liabilities:Credit Card           $-50.00
     (Funds:School)                   $-100.00
 @end smallexample
-@c TODO: Is the following section still relevant / correct? ledger seems to have lost --code-as-payee
 
 The second way of tracking funds is to use transaction codes.  In this
 respect the codes become like virtual accounts that embrace the entire
@@ -1391,11 +1390,15 @@ set of postings.  Basically, we are associating a transaction with a
 fund by setting its code.  Here are two transactions that deposit money
 into, and spend money from, the @samp{Funds:School} fund:
 
-@smallexample
+@smallexample @c input:AD068BA
 2004/03/25 (Funds:School) Donations
     Assets:Checking                   $100.00
     Income:Donations
 
+2004/03/25 (Funds:Teachers) Donations
+    Assets:Checking                   $20.00
+    Income:Donations
+
 2004/04/25 (Funds:School) Payment for books
     Expenses:Books                     $50.00
     Assets:Checking
@@ -1405,7 +1408,7 @@ Note how the accounts now relate only to the real accounts, and any
 balance or registers reports will reflect this.  That the transactions
 relate to a particular fund is kept only in the code.
 
-@findex --code-as-payee
+@findex --payee=code
 @findex --by-payee
 How does this become a fund report?  By using the
 @option{--code-as-payee} option, you can generate a register report
@@ -1415,15 +1418,24 @@ terribly interesting; but when combined with the @option{--by-payee
 related to a specific fund.  So, to see the current monetary balances of
 all funds, the command would be:
 
-@smallexample
-$ ledger --code-as-payee -P reg ^Assets
+@smallexample @c command:AD068BA
+$ ledger --payee=code -P reg ^Assets
 @end smallexample
 
-Or to see a particular funds expenses, the @samp{School} fund in this
+@smallexample @c output:AD068BA
+04-Mar-25 Funds:School          Assets:Checking              $50.00       $50.00
+04-Mar-25 Funds:Teachers        Assets:Checking              $20.00       $70.00
+@end smallexample
+
+Or to see a particular fund's expenses, the @samp{School} fund in this
 case:
 
-@smallexample
-$ ledger --code-as-payee -P reg ^Expenses @@School
+@smallexample @c command:E30B2FC,with_input:AD068BA
+$ ledger --payee=code -P reg ^Expenses and code School
+@end smallexample
+
+@smallexample @c output:E30B2FC
+04-Apr-25 Funds:School          Expenses:Books               $50.00       $50.00
 @end smallexample
 
 Both approaches yield different kinds of flexibility, depending on how
@@ -1482,7 +1494,7 @@ posting.
 Here is the Pacific Bell example from above, given as a Ledger
 posting, with the additional of a check number:
 
-@smallexample
+@smallexample @c input:validate
 9/29 (1023) Pacific Bell
     Expenses:Utilities:Phone                   $23.00
     Assets:Checking                           $-23.00
@@ -1494,7 +1506,7 @@ work better with Ledger's scheme of things.  In fact, since Ledger is
 smart about many things, you don't need to specify the balanced
 amount, if it is the same as the first line:
 
-@smallexample
+@smallexample @c input:validate
 9/29 (1023) Pacific Bell
     Expenses:Utilities:Phone                   $23.00
     Assets:Checking
@@ -1536,7 +1548,7 @@ basis of the opening entry for ledger. For example if you chose the
 beginning of 2011 as the date to start tracking finances with ledger,
 your opening balance entry could look like this:
 
-@smallexample
+@smallexample @c input:validate
 2011/01/01 * Opening Balance
     Assets:Joint Checking                   $800.14
     Assets:Other Checking                    $63.44
@@ -1598,7 +1610,7 @@ beginning of a line: @samp{#}, @samp{|}, and @samp{*} and @samp{%}.
 Block comments can be made by use @code{comment} ... @code{end
 comment}.
 
-@smallexample
+@smallexample @c input:validate
 ; This is a single line comment,
 #  and this,
 %   and this,
@@ -1613,7 +1625,7 @@ end comment
 
 There are several forms of comments within a transaction, for example:
 
-@smallexample
+@smallexample @c input:validate
 ; this is a global comment that is not applied to a specific transaction
 ; it can start with any of the five characters but is not included in the
 ; output from 'print' or 'output'
@@ -1712,7 +1724,7 @@ Commodity names can have any character, including white-space.
 However, if you include white-space or numeric characters the
 commodity name must be enclosed in double quotes @samp{"}:
 
-@smallexample
+@smallexample @c input:validate
 1999/06/09 ! Achat
     Actif:SG PEE STK         49.957 "Arcancia Équilibre 454"
     Actif:SG PEE STK      $-234.90
@@ -1732,22 +1744,22 @@ multiple commodities in the same transaction.  The type of the share
 unit you made the purchase in ($ for AAPL). Yes, the typical
 convention is as follows:
 
-@smallexample
+@smallexample @c input:validate
 2004/05/01 Stock purchase
     Assets:Broker                     50 AAPL @@ $30.00
     Expenses:Broker:Commissions        $19.95
-    Assets:Broker                  $-1,500.00
+    Assets:Broker                  $-1,519.95
 @end smallexample
 
 This assumes you have a brokerage account that is capable of managed
 both liquid and commodity assets.  Now, on the day of the sale:
 
-@smallexample
+@smallexample @c input:validate
 2005/08/01 Stock sale
     Assets:Broker                    -50 APPL @{$30.00@} @@ $50.00
     Expenses:Broker:Commissions        $19.95
     Income:Capital Gains           $-1,000.00
-    Assets:Broker                   $2,500.00
+    Assets:Broker                   $2,480.05
 @end smallexample
 
 @noindent
@@ -1778,7 +1790,7 @@ reported in terms of today's price.
 
 This is supported as follows:
 
-@smallexample
+@smallexample @c input:validate
 2009/01/01 Shell
     Expenses:Gasoline             11 GAL @{=$2.299@}
     Assets:Checking
@@ -1792,7 +1804,7 @@ If you do not want price fixing, you can specify this same transaction
 in one of two ways, both equivalent (note the lack of the equal sign
 from the transaction above):
 
-@smallexample
+@smallexample @c input:validate
 2009/01/01 Shell
     Expenses:Gasoline             11 GAL @{$2.299@}
     Assets:Checking
@@ -1805,7 +1817,7 @@ from the transaction above):
 There is no difference in meaning between these two forms.  Why do
 both exist, you ask?  To support things like this:
 
-@smallexample
+@smallexample @c input:validate
 2009/01/01 Shell
     Expenses:Gasoline             11 GAL @{=$2.299@} @@ $2.30
     Assets:Checking
@@ -2124,7 +2136,7 @@ Pre-declare valid account names.  This only has effect if
 they immediately follow the account directive and if they begin with
 whitespace:
 
-@smallexample
+@smallexample @c input:validate
 account Expenses:Food
     note This account is all about the chicken!
     alias food
@@ -2148,7 +2160,7 @@ provides regexes that identify the account if that payee is
 encountered and an account within its transaction ends in the name
 "Unknown".  Example:
 
-@smallexample
+@smallexample @c input:validate
 2012-02-27 KFC
     Expenses:Unknown      $10.00  ; Read now as "Expenses:Food"
     Assets:Cash
@@ -2177,7 +2189,7 @@ and all business account with @samp{business:}.  You can easily split
 out large groups of transaction without manually editing them using
 the account directive.  For example:
 
-@smallexample
+@smallexample @c input:validate
 apply account Personal
 2011/11/15  Supermarket
     Expenses:Groceries      $ 50.00
@@ -2193,7 +2205,7 @@ until an @samp{end apply account} directive was found.
 Define an alias for an account name.  If you have a deeply nested tree
 of accounts, it may be convenient to define an alias, for example:
 
-@smallexample
+@smallexample @c input:94A99E8
 alias Dining=Expenses:Entertainment:Dining
 alias Checking=Assets:Credit Union:Joint Checking Account
 
@@ -2206,11 +2218,19 @@ The aliases are only in effect for transactions read in after the alias
 is defined and are affected by @code{account} directives that precede
 them.
 
+@smallexample @c command:94A99E8
+$ ledger bal --no-total ^Exp
+@end smallexample
+
+@smallexample @c output:94A99E8
+              $10.00  Expenses:Entertainment:Dining
+@end smallexample
+
 With the option @option{--recursive-aliases}, aliases can refer to other aliases,
 the following example produces exactly the same transactions and account names
 as the preceding one:
 
-@smallexample
+@smallexample @c input:83E1FB3
 alias Entertainment=Expenses:Entertainment
 alias Dining=Entertainment:Dining
 alias Checking=Assets:Credit Union:Joint Checking Account
@@ -2220,6 +2240,14 @@ alias Checking=Assets:Credit Union:Joint Checking Account
   Checking
 @end smallexample
 
+@smallexample @c command:83E1FB3
+$ ledger balance --no-total --recursive-aliases ^Exp
+@end smallexample
+
+@smallexample @c output:83E1FB3
+              $10.00  Expenses:Entertainment:Dining
+@end smallexample
+
 The option @option{--no-aliases} completely disables alias expansion.
 
 @item assert
@@ -2242,7 +2270,7 @@ automatically generate an additional posting to the bucket account
 balancing the transaction.  The following example set the
 @samp{Assets:Checking} as the bucket:
 
-@smallexample
+@smallexample @c input:validate
 bucket Assets:Checking
 2011/01/25 Tom's Used Cars
     Expenses:Auto                    $ 5,500.00
@@ -2262,7 +2290,7 @@ bucket Assets:Checking
 Directs Ledger to replace any account matching a regex with the given
 account. For example:
 
-@smallexample
+@smallexample @c input:validate
 capture  Expenses:Deductible:Medical  Medical
 @end smallexample
 
@@ -2289,7 +2317,7 @@ Start a block comment, closed by @code{end comment}.
 Pre-declare commodity names.  This only has effect if @option{--strict}
 or @option{--pedantic} is used (see below).
 
-@smallexample
+@smallexample @c input:validate
 commodity $
 commodity CAD
 @end smallexample
@@ -2298,7 +2326,7 @@ The @code{commodity} directive supports several optional
 sub-directives, if they immediately follow the commodity directive and
 if they begin with whitespace:
 
-@smallexample
+@smallexample @c input:validate
 commodity $
    note American Dollars
    format $1,000.00
@@ -2323,7 +2351,7 @@ The @code{default} directive marks this as the ``default'' commodity.
 @c instance_t::define_directive in textual.cc
 Allows you to define value expression for future use. For example:
 
-@smallexample
+@smallexample @c input:validate
 define var_name=$100
 
 2011/12/01 Test
@@ -2349,21 +2377,21 @@ use when entering many transactions with fixated prices.
 
 Thus, the following:
 
-@smallexample
+@smallexample @c input:validate
 fixed CAD $0.90
-   2012-04-10 Lunch in Canada
-       Assets:Wallet            -15.50 CAD
-       Expenses:Food            15.50 CAD
+2012-04-10 Lunch in Canada
+    Assets:Wallet            -15.50 CAD
+    Expenses:Food            15.50 CAD
 
-   2012-04-11 Second day Dinner in Canada
-       Assets:Wallet            -25.75 CAD
-       Expenses:Food            25.75 CAD
+2012-04-11 Second day Dinner in Canada
+    Assets:Wallet            -25.75 CAD
+    Expenses:Food            25.75 CAD
 endfixed
 @end smallexample
 
 is equivalent to this:
 
-@smallexample
+@smallexample @c input:validate
 2012-04-10 Lunch in Canada
     Assets:Wallet            -15.50 CAD @{=$0.90@}
     Expenses:Food            15.50 CAD  @{=$0.90@}
@@ -2394,7 +2422,7 @@ The @code{payee} directive supports one optional sub-directive, if it
 immediately follows the payee directive and if it begins with
 whitespace:
 
-@smallexample
+@smallexample @c input:validate
 payee KFC
     alias KENTUCKY FRIED CHICKEN
 @end smallexample
@@ -2415,7 +2443,7 @@ Ledger will display the mapped payees in @command{print} and
 Allows you to designate a block of transactions and assign the same
 tag to all.  Tags can have values and may be nested.
 
-@smallexample
+@smallexample @c input:validate
 apply tag hastag
 apply tag nestedtag: true
 
@@ -2428,34 +2456,34 @@ apply tag nestedtag: true
     Expenses:Books                       $20.00
     Liabilities:MasterCard
 
-end apply tag nestedtag
+end apply tag
 
 2011/12/01 Sale
     Assets:Checking:Business            $ 30.00
     Income:Sales
 
-end apply tag hastag
+end apply tag
 @end smallexample
 
 @noindent
 is the equivalent of:
 
-@smallexample
+@smallexample @c input:validate
 2011/01/25 Tom's Used Cars
-    :hastag:
-    nestedtag: true
+    ; :hastag:
+    ; nestedtag: true
     Expenses:Auto                    $ 5,500.00
     ; :nobudget:
     Assets:Checking
 
 2011/01/27 Book Store
-    :hastag:
-    nestedtag: true
+    ; :hastag:
+    ; nestedtag: true
     Expenses:Books                       $20.00
     Liabilities:MasterCard
 
 2011/12/01 Sale
-    :hastag:
+    ; :hastag:
     Assets:Checking:Business            $ 30.00
     Income:Sales
 @end smallexample
@@ -2468,7 +2496,7 @@ track.
 Pre-declares tag names.  This only has effect if @option{--strict} or
 @option{--pedantic} is used (see below).
 
-@smallexample
+@smallexample @c input:validate
 tag Receipt
 tag CSV
 @end smallexample
@@ -2477,7 +2505,7 @@ The @code{tag} directive supports two optional sub-directives, if they
 immediately follow the tag directive and if they begin with
 whitespace:
 
-@smallexample
+@smallexample @c input:validate
 tag Receipt
   check value =~ /pattern/
   assert value != "foobar"
@@ -2538,7 +2566,7 @@ whichever is seen last is used as the default commodity.  For example,
 to set US dollars as the default commodity, while also setting the
 thousands flag and decimal flag for that commodity, use:
 
-@smallexample
+@smallexample @c input:validate
 D $1,000.00
 @end smallexample
 
@@ -2547,7 +2575,7 @@ Specifies a commodity conversion, where the first amount is given to
 be equivalent to the second amount.  The first amount should use the
 decimal precision desired during reporting:
 
-@smallexample
+@smallexample @c input:validate
 C 1.00 Kb = 1024 bytes
 @end smallexample
 
@@ -2673,7 +2701,7 @@ doing it.
 
 The most basic form of transaction is:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 KFC
     Expenses:Food                $20.00
     Assets:Cash                 $-20.00
@@ -2685,7 +2713,7 @@ posting specifies what action is taken related to that account.
 
 A transaction can have any number of postings:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 KFC
     Expenses:Food                $20.00
     Assets:Cash                 $-10.00
@@ -2699,7 +2727,7 @@ The first thing you can do to make things easier is elide amounts.
 That is, if exactly one posting has no amount specified, Ledger will
 infer the inverse of the other postings' amounts:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 KFC
     Expenses:Food                $20.00
     Assets:Cash                 $-10.00
@@ -2711,7 +2739,7 @@ If the other postings use multiple commodities, Ledger will copy the
 empty posting N times and fill in the negated values of the various
 commodities:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 KFC
     Expenses:Food                $20.00
     Expenses:Tips                 $2.00
@@ -2723,7 +2751,7 @@ commodities:
 @noindent
 This transaction is identical to writing:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 KFC
     Expenses:Food                $20.00
     Expenses:Tips                 $2.00
@@ -2741,7 +2769,7 @@ This transaction is identical to writing:
 You can associate a second date with a transaction by following the
 primary date with an equals sign:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10=2012-03-08 KFC
     Expenses:Food                $20.00
     Assets:Cash                 $-20.00
@@ -2760,7 +2788,7 @@ only displayed by the print command.  Checking accounts often use
 codes like DEP, XFER, etc., as well as check numbers.  This is to give
 you a place to put those codes:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 (#100) KFC
     Expenses:Food                $20.00
     Assets:Checking
@@ -2776,7 +2804,7 @@ A transaction can have a ``state'': cleared, pending, or uncleared.
 The default is uncleared.  To mark a transaction cleared, put a *
 before the payee, and after date or code:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 * KFC
     Expenses:Food                $20.00
     Assets:Cash
@@ -2785,7 +2813,7 @@ before the payee, and after date or code:
 @noindent
 To mark it pending, use a !:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 ! KFC
     Expenses:Food                $20.00
     Assets:Cash
@@ -2803,7 +2831,7 @@ a reconciliation.
 When you clear a transaction, that's really just shorthand for
 clearing all of its postings.  That is:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 * KFC
     Expenses:Food                $20.00
     Assets:Cash
@@ -2812,7 +2840,7 @@ clearing all of its postings.  That is:
 @noindent
 Is the same as writing:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 KFC
     * Expenses:Food                $20.00
     * Assets:Cash
@@ -2822,7 +2850,7 @@ Is the same as writing:
 You can mark individual postings as cleared or pending, in case one
 ``side'' of the transaction has cleared, but the other hasn't yet:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 KFC
     Liabilities:Credit            $100.00
     * Assets:Checking
@@ -2835,7 +2863,7 @@ After the payee, and after at least one tab or two spaces (or a space
 and a tab, which Ledger calls this a ``hard separator''), you may
 introduce a note about the transaction using the @samp{;} character:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 * KFC                ; yum, chicken...
     Expenses:Food                $20.00
     Assets:Cash
@@ -2845,7 +2873,7 @@ introduce a note about the transaction using the @samp{;} character:
 Notes can also appear on the next line, so long as that line begins
 with whitespace:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 * KFC                ; yum, chicken...
     ; and more notes...
     Expenses:Food                $20.00
@@ -2862,7 +2890,7 @@ significant when querying for metadata (see below).  To specify that
 a note belongs only to one posting, place it after a hard separator
 after the amount, or on its own line preceded by whitespace:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 * KFC
     Expenses:Food                $20.00  ; posting #1 note
     Assets:Cash
@@ -2900,7 +2928,7 @@ The are two forms of metadata: tags and tag/value pairs.
 To tag an item, put any word not containing whitespace between two
 colons:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 * KFC
     Expenses:Food                $20.00
     Assets:Cash
@@ -2909,7 +2937,7 @@ colons:
 
 You can gang up multiple tags by sharing colons:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 * KFC
     Expenses:Food                $20.00
     Assets:Cash
@@ -2936,7 +2964,7 @@ This is useful when for example you deposit 4 checks at a time to
 the bank. On the bank statement, there is just one amount @samp{$400},
 but you can specify from whom each check came from, as shown by example below:
 
-@smallexample
+@smallexample @c input:validate
 2010-06-17 Sample
     Assets:Bank        $400.00
     Income:Check1     $-100.00  ; Payee: Person One
@@ -2965,7 +2993,7 @@ To associate a value with a tag, use the syntax ``Key: Value'', where
 the value can be any string of characters.  Whitespace is needed after
 the colon, and cannot appear in the Key:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 * KFC
     Expenses:Food                $20.00
     Assets:Cash
@@ -2979,7 +3007,7 @@ If a metadata tag ends in ::, its value will be parsed as a value
 expression and stored internally as a value rather than as a string.
 For example, although I can specify a date textually like so:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 * KFC
     Expenses:Food                $20.00
     Assets:Cash
@@ -3020,7 +3048,7 @@ reports using @option{--real}.
 To specify a virtual account, surround the account name with
 parentheses:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 * KFC
     Expenses:Food                $20.00
     Assets:Cash
@@ -3031,7 +3059,7 @@ If you want, you can state that virtual postings @emph{should} balance
 against one or more other virtual postings by using brackets (which
 look ``harder'') rather than parentheses:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 * KFC
     Expenses:Food                $20.00
     Assets:Cash
@@ -3046,7 +3074,7 @@ An amount is usually a numerical figure with an (optional) commodity,
 but it can also be any value expression.  To indicate this, surround
 the amount expression with parentheses:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 * KFC
     Expenses:Food      ($10.00 + $20.00)  ; Ledger adds it up for you
     Assets:Cash
@@ -3106,7 +3134,7 @@ Say your book-keeping has gotten a bit out of date, and your Ledger
 balance no longer matches your bank balance.  You can create an
 adjustment transaction using balance assignments:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 Adjustment
     Assets:Cash                         = $500.00
     Equity:Adjustments
@@ -3152,7 +3180,7 @@ In those cases, Ledger will remember the ``cost'' of that transaction
 for you, and can use it during reporting in various ways.  Here's an
 example of a stock purchase:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 My Broker
     Assets:Brokerage             10 AAPL
     Assets:Brokerage:Cash       $-500.00
@@ -3168,7 +3196,7 @@ another.  The resulting posting cost is $50.00 per share.
 You can make any posting's cost explicit using the @samp{@@} symbol
 after the amount or amount expression:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 My Broker
     Assets:Brokerage             10 AAPL @@ $50.00
     Assets:Brokerage:Cash       $-500.00
@@ -3177,7 +3205,7 @@ after the amount or amount expression:
 When you do this, since Ledger can now figure out the balancing amount
 from the first posting's cost, you can elide the other amount:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 My Broker
     Assets:Brokerage             10 AAPL @@ $50.00
     Assets:Brokerage:Cash
@@ -3213,7 +3241,7 @@ flag will never convert a primary commodity into any other commodity.
 Just as you can have amount expressions, you can have posting
 expressions:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 My Broker
     Assets:Brokerage             10 AAPL @@ ($500.00 / 10)
     Assets:Brokerage:Cash
@@ -3221,7 +3249,7 @@ expressions:
 
 You can even have both:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 My Broker
     Assets:Brokerage             (5 AAPL * 2) @@ ($500.00 / 10)
     Assets:Brokerage:Cash
@@ -3234,7 +3262,7 @@ The cost figure following the @samp{@@} character specifies the
 @emph{per-unit} price for the commodity being transferred.  If you'd
 like to specify the total cost instead, use @samp{@@@@}:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 My Broker
     Assets:Brokerage             10 AAPL @@@@ $500.00
     Assets:Brokerage:Cash
@@ -3242,7 +3270,7 @@ like to specify the total cost instead, use @samp{@@@@}:
 
 Ledger reads this as if you had written:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 My Broker
     Assets:Brokerage             10 AAPL @@ ($500.00 / 10)
     Assets:Brokerage:Cash
@@ -3257,7 +3285,7 @@ Ledger's internal price history database.  To prevent this from
 happening in the case of an exceptional transaction, surround the
 @samp{@@} or @samp{@@@@} with parentheses:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 My Brother
     Assets:Brokerage            1000 AAPL (@@) $1
     Income:Gifts Received
@@ -3275,7 +3303,7 @@ to show these hidden price figures.
 
 For example, consider the stock sale given above:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 My Broker
     Assets:Brokerage             10 AAPL @@ $50.00
     Assets:Brokerage:Cash
@@ -3290,7 +3318,7 @@ $5.00 was the price of that exchange.
 This becomes significant if you later sell that commodity again.  For
 example, you might write this:
 
-@smallexample
+@smallexample @c input:validate
 2012-04-10 My Broker
     Assets:Brokerage:Cash
     Assets:Brokerage            -10 AAPL @@ $75.00
@@ -3299,7 +3327,7 @@ example, you might write this:
 And that would be perfectly fine, but how do you track the capital
 gains on the sale?  It could be done with a virtual posting:
 
-@smallexample
+@smallexample @c input:validate
 2012-04-10 My Broker
     Assets:Brokerage:Cash
     Assets:Brokerage            -10 AAPL @@ $75.00
@@ -3335,7 +3363,7 @@ As a shorthand, you can specify the total price instead of the
 per-share price in doubled braces.  This goes well with total costs,
 but is not required to be used with them:
 
-@smallexample
+@smallexample @c input:validate
 2012-04-10 My Broker
     Assets:Brokerage:Cash       $750.00
     Assets:Brokerage            -10 AAPL @{@{$500.00@}@} @@@@ $750.00
@@ -3565,7 +3593,7 @@ same query syntax as the Ledger command line.
 
 Consider this posting:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 KFC
     Expenses:Food                $20.00
     Assets:Cash
@@ -3573,7 +3601,7 @@ Consider this posting:
 
 If I write this automated transaction before it in the file:
 
-@smallexample
+@smallexample @c input:validate
 = expr true
     Foo                          $50.00
     Bar                         $-50.00
@@ -3582,7 +3610,7 @@ If I write this automated transaction before it in the file:
 Then the first transaction will be modified during parsing as if I'd
 written this:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 KFC
     Expenses:Food                $20.00
     Foo                          $50.00
@@ -3619,7 +3647,7 @@ As a special case, if an automated transaction's posting's amount
 (phew) has no commodity, it is taken as a multiplier upon the matching
 posting's cost.  For example:
 
-@smallexample
+@smallexample @c input:validate
 = expr true
     Foo                           50.00
     Bar                          -50.00
@@ -3631,7 +3659,7 @@ posting's cost.  For example:
 
 Then the latter transaction turns into this during parsing:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 KFC
     Expenses:Food                $20.00
     Foo                        $1000.00
@@ -3649,7 +3677,7 @@ posting, that expression has access to all the details of the matched
 posting.  For example, you can refer to that posting's amount using
 the ``amount'' value expression variable:
 
-@smallexample
+@smallexample @c input:validate
 = expr true
     (Foo)                  (amount * 2)  ; same as just "2" in this case
 
@@ -3660,7 +3688,7 @@ the ``amount'' value expression variable:
 
 This becomes:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 KFC
     Expenses:Food                $20.00
     (Foo)                        $40.00
@@ -3675,7 +3703,7 @@ Sometimes want to refer to the account that matched in some way within
 the automated transaction itself.  This is done by using the string
 $account, anywhere within the account part of the automated posting:
 
-@smallexample
+@smallexample @c input:validate
 = food
     (Budget:$account)                10
 
@@ -3686,7 +3714,7 @@ $account, anywhere within the account part of the automated posting:
 
 Becomes:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 KFC
     Expenses:Food                $20.00
     (Budget:Expenses:Food)      $200.00
@@ -3700,7 +3728,7 @@ If the automated transaction has a transaction note, that note is
 copied (along with any metadata) to every posting that matches the
 predicate:
 
-@smallexample
+@smallexample @c input:validate
 = food
     ; Foo: Bar
     (Budget:$account)                10
@@ -3712,7 +3740,7 @@ predicate:
 
 Becomes:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 KFC
     Expenses:Food                $20.00
       ; Foo: Bar
@@ -3726,7 +3754,7 @@ Becomes:
 If the automated transaction's posting has a note, that note is
 carried to the generated posting within the matched transaction:
 
-@smallexample
+@smallexample @c input:validate
 = food
     (Budget:$account)                10
       ; Foo: Bar
@@ -3738,7 +3766,7 @@ carried to the generated posting within the matched transaction:
 
 Becomes:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-10 KFC
     Expenses:Food                $20.00
     (Budget:Expenses:Food)      $200.00
@@ -3774,7 +3802,7 @@ something like
 
 @cindex effective date of invoice
 
-@smallexample
+@smallexample @c input:validate
 2008/01/01=2008/01/14 Client invoice  ;  estimated date you'll be paid
     Assets:Accounts Receivable            $100.00
     Income: Client name
@@ -3782,7 +3810,7 @@ something like
 
 Then, when you receive the payment, you change it to
 
-@smallexample
+@smallexample @c input:validate
 2008/01/01=2008/01/15 Client invoice ;  actual date money received
     Assets:Accounts Receivable            $100.00
     Income: Client name
@@ -3791,7 +3819,7 @@ Then, when you receive the payment, you change it to
 @noindent
 and add something like
 
-@smallexample
+@smallexample @c input:validate
 2008/01/15 Client payment
     Assets:Checking                       $100.00
     Assets:Accounts Receivable
@@ -3799,14 +3827,14 @@ and add something like
 
 Now
 
-@smallexample
+@smallexample @c command:validate
 $ ledger --begin 2008/01/01 --end 2008/01/14 bal Income
 @end smallexample
 
 @noindent
 gives you your accrued income in the first two weeks of the year, and
 
-@smallexample
+@smallexample @c command:validate
 $ ledger --effective --begin 2008/01/01 --end 2008/01/14 bal Income
 @end smallexample
 
@@ -3905,7 +3933,7 @@ much is owed in order to fulfill one's obligation to Huqúqu'lláh.
 When ready to pay, just write a check to cover the amount shown in
 @samp{Liabilities:Huququ'llah}.  That transaction would look like:
 
-@smallexample
+@smallexample @c input:validate
 2003/01/01 (101) Baha'i Huqúqu'lláh Trust
     Liabilities:Huququ'llah          $1,000.00
     Assets:Checking
@@ -3929,6 +3957,7 @@ appear in the balance report only when it exceeds the present day
 value of 2.22 ounces of gold.  This can be accomplished using the
 command:
 
+@c TODO: fix this
 @smallexample
 $ ledger -Q -t "/Liab.*Huquq/?(a/P@{2.22 AU@}<=@{-1.0@}&a):a" bal liab
 @end smallexample
@@ -3938,6 +3967,7 @@ Huqúqu'lláh is reported only if its value exceeds that of 2.22 ounces
 of gold.  If you wish the liability to be reflected in the parent
 subtotal either way, use this instead:
 
+@c TODO: fix this
 @smallexample
 $ ledger -Q -T "/Liab.*Huquq/?(O/P@{2.22 AU@}<=@{-1.0@}&O):O" bal liab
 @end smallexample
@@ -3946,7 +3976,7 @@ In some cases, you may wish to refer to the account of whichever posting
 matched your automated transaction's value expression.  To do this, use
 the special account name @samp{$account}:
 
-@smallexample
+@smallexample @c input:validate
 = /^Some:Long:Account:Name/
     [$account]  -0.10
     [Savings]    0.10
@@ -4084,9 +4114,12 @@ This second example looks for any account with @samp{Bo}, which is
 If you want to know exactly how much you have spent in a particular
 account on a particular payee, the following are equivalent:
 
-@smallexample
+@smallexample @c command:validate
 $ ledger balance Auto:Fuel and Chevron
-$ ledger balance --limit "(account=~/Fuel/) & (payee=~/Chev/)"
+@end smallexample
+
+@smallexample @c command:validate
+$ ledger balance --limit 'account=~/Fuel/' and 'payee=~/Chev/'
 @end smallexample
 
 @noindent
@@ -4099,8 +4132,8 @@ possibilities.
 If you want to exclude specific accounts from the report, you can
 exclude multiple accounts with parentheses:
 
-@smallexample
-$ ledger bal Expenses and not \(Expenses:Drinks or Expenses:Candy or Expenses:Gifts\)
+@smallexample @c command:validate
+$ ledger bal Expenses and not (Expenses:Drinks or Expenses:Candy or Expenses:Gifts)
 @end smallexample
 
 @node Controlling Formatting,  , Controlling the Accounts and Payees, Balance Reports
@@ -4116,8 +4149,9 @@ you want, or interface Ledger with other programs.
 A query such as the following shows all expenses since last
 October, sorted by total:
 
+@c TODO: does not validate with @c command:validate, because "last oct" is split at the space
 @smallexample
-$ ledger -b "last oct" -S T bal ^expenses
+$ ledger -b "last oct" -f sample.dat -S T bal ^expenses
 @end smallexample
 
 From left to right the options mean: Show transactions since last
@@ -4139,7 +4173,7 @@ for all accounts that begin with @samp{expenses}.
 The following query makes it easy to see monthly expenses, with each
 month's expenses sorted by the amount:
 
-@smallexample
+@smallexample @c command:validate
 $ ledger -M --period-sort "(amount)" reg ^expenses
 @end smallexample
 
@@ -4147,7 +4181,7 @@ Now, you might wonder where the money came from to pay for these things.
 To see that report, add @option{--related (-r)}, which shows the
 ``related account'' postings:
 
-@smallexample
+@smallexample @c command:validate
 $ ledger -M --period-sort "(amount)" -r reg ^expenses
 @end smallexample
 
@@ -4157,8 +4191,8 @@ requires the use of a display predicate, since the postings
 calculated must match @samp{^expenses}, while the postings
 displayed must match @samp{mastercard}.  The command would be:
 
-@smallexample
-$ ledger -M -r --display "account =~ /mastercard/" reg ^expenses
+@smallexample @c command:validate
+$ ledger -M -r --display 'account=~/mastercard/' reg ^expenses
 @end smallexample
 
 This query says: Report monthly subtotals; report the ``related
@@ -4168,8 +4202,8 @@ postings matching @samp{^expenses}.
 
 This works just as well for report the overall total, too:
 
-@smallexample
-$ ledger -s -r --display "account =~ /mastercard/" reg ^expenses
+@smallexample @c command:validate
+$ ledger -s -r --display "account=~/mastercard/" reg ^expenses
 @end smallexample
 
 The @option{--subtotal (-s)} option subtotals all postings, just as
@@ -4232,7 +4266,7 @@ actual balances.
 For the three instruments listed above, those automatic transactions
 would look like:
 
-@smallexample
+@smallexample @c input:validate
 ;
 ; automatic calculations for asset allocation tracking
 ;
@@ -4264,6 +4298,7 @@ the various asset classes how do we get a report that tells us our
 current allocation?  Using the balance command and some tricky
 formatting!
 
+@c TODO: does not @c command:validate due to multiple lines
 @smallexample
 ledger bal Allocation --current --format "\
         %-17((depth_spacer)+(partial_account))\
@@ -4553,7 +4588,7 @@ directive to rewrite the @code{payee} field based on some rules. Then
 you can use the account and its @code{payee} directive to specify the
 account. I use it like this, for example:
 
-@smallexample
+@smallexample @c input:validate
 payee Aldi
     alias ^ALDI SUED SAGT DANKE
 account Aufwand:Einkauf:Lebensmittel
@@ -5292,14 +5327,14 @@ instead, precede the regular expression with @samp{payee} or
 totals for rent, food and movies, but only those whose payee matches
 Freddie:
 
-@smallexample
+@smallexample @c command:validate
 $ ledger bal rent food movies payee freddie
 @end smallexample
 
 @noindent
 or
 
-@smallexample
+@smallexample @c command:validate
 $ ledger bal rent food movies @@freddie
 @end smallexample
 
@@ -5993,8 +6028,8 @@ that date will be ignored.
 Print the entire line in bold if the given value expression is true
 (@pxref{Value Expressions}).
 
-@smallexample
-$ ledger reg Expenses --begin Dec --bold-if "amount > 100"
+@smallexample @c command:validate
+$ ledger reg Expenses --begin Dec --bold-if "amount>100"
 @end smallexample
 
 @noindent
@@ -6184,7 +6219,7 @@ calculations occur.
 @itemx --days-of-week
 Group transactions by the days of the week.
 
-@smallexample
+@smallexample @c command:validate
 $ ledger reg Expenses --dow --collapse
 @end smallexample
 
@@ -6284,7 +6319,7 @@ Use @code{Expected} amounts in calculations.  In the case that you know
 that amount a transaction should be, but the actual transaction has the
 wrong value you can use metadata to put in the expected amount:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-12  Paycheck
     Income  $-990;  Expected:: $-1000.00
     Checking
@@ -6670,7 +6705,7 @@ expression @var{EXPR}.  This is most often useful when reporting
 monthly expenses, in order to view the highest expense categories at
 the top of each month:
 
-@smallexample
+@smallexample @c input:validate
 $ ledger -M --period-sort -At reg ^Expenses
 @end smallexample
 
@@ -6911,6 +6946,7 @@ register report, for example, but they will not be displayed.  This is
 useful for seeing last month's checking postings, against a running
 balance which includes all posting values:
 
+@c TODO: does not @c command:validate due to space in "last month"
 @smallexample
 $ ledger -d "d>=[last month]" reg checking
 @end smallexample
@@ -6919,6 +6955,7 @@ The output from this command is very different from the following,
 whose running total includes only postings from the last month
 onward:
 
+@c TODO: does not @c command:validate due to space in "last month"
 @smallexample
 $ ledger -p "last month" reg checking
 @end smallexample
@@ -7160,7 +7197,7 @@ If no @var{VALUE} property is specified, each posting is assumed to have
 a default, as if you'd specified a global, automated transaction as
 follows:
 
-@smallexample
+@smallexample @c input:validate
 = expr true
     ; VALUE:: market(amount, date, exchange)
 @end smallexample
@@ -7174,7 +7211,7 @@ This definition emulates the present day behavior of @option{--market
 One thing many people have wanted to do is to fixate the valuation of
 old European currencies in terms of the Euro after a certain date:
 
-@smallexample
+@smallexample @c input:validate
 = expr commodity == "DM"
     ; VALUE:: date < [Jun 2008] ? market(amount, date, exchange) : 1.44 EUR
 @end smallexample
@@ -7186,7 +7223,7 @@ past June 2008, use a fixed price for converting Deutsch Mark to Euro.
 Or how about never re-valuating commodities used in Expenses, since
 they cannot have a different future value:
 
-@smallexample
+@smallexample @c input:validate
 = /^Expenses:/
     ; VALUE:: market(amount, post.date, exchange)
 @end smallexample
@@ -7198,7 +7235,7 @@ the value of @option{--now @var{DATE}} (defaults to today).
 Or how about valuating miles based on a reimbursement rate during a
 specific time period:
 
-@smallexample
+@smallexample @c input:validate
 = expr commodity == "miles" and date >= [2007] and date < [2008]
     ; VALUE:: market($1.05, date, exchange)
 @end smallexample
@@ -7212,7 +7249,7 @@ Note that you can have a valuation expression specific to a particular
 posting or transaction, by overriding these general defaults using
 specific meta-data:
 
-@smallexample
+@smallexample @c input:validate
 2010-12-26 Example
     Expenses:Food                $20
     ; Just to be silly, always valuate *these* $20 as 30 DM, no matter what
@@ -7232,7 +7269,7 @@ which allows you to report most everything in EUR if you use @samp{-X
 EUR}, except for certain accounts or postings which should always be
 valuated in another currency.  For example:
 
-@smallexample
+@smallexample @c input:validate
 = /^Assets:Brokerage:CAD$/
     ; Always report the value of commodities in this account in
     ; terms of present day dollars, despite what was asked for
@@ -7417,7 +7454,7 @@ period transaction is almost identical to a regular transaction, except
 that it begins with a tilde and has a period expression in place of a
 payee.  For example:
 
-@smallexample
+@smallexample @c input:validate
 ~ Monthly
     Expenses:Rent               $500.00
     Expenses:Food               $450.00
@@ -7448,13 +7485,13 @@ Once these period transactions are defined, creating a budget report is
 as easy as adding @option{--budget} to the command-line.  For example,
 a typical monthly expense report would be:
 
-@smallexample
+@smallexample @c command:validate
 $ ledger --monthly register ^expenses
 @end smallexample
 
 To see the same report balanced against your budget, use:
 
-@smallexample
+@smallexample @c command:validate
 $ ledger --budget --monthly register ^expenses
 @end smallexample
 
@@ -7463,7 +7500,7 @@ To see all expenses balanced against the budget, use
 @option{--add-budget}.  You can even see only the un-budgeted expenses
 using @option{--unbudgeted}:
 
-@smallexample
+@smallexample @c command:validate
 $ ledger --unbudgeted --monthly register ^expenses
 @end smallexample
 
@@ -7478,7 +7515,7 @@ future, such as determining when an account will reach zero.  Ledger
 makes this easy to do, using the same period transactions as are used
 for budgeting.  An example forecast report can be generated with:
 
-@smallexample
+@smallexample @c command:validate
 $ ledger --forecast "T>@{\$-500.00@}" register ^assets ^liabilities
 @end smallexample
 
@@ -7489,7 +7526,7 @@ show you what the total afterwards would be.
 Forecasting can also be used with the balance report, but by date
 only, and not against the running total:
 
-@smallexample
+@smallexample @c command:validate
 $ ledger --forecast "d<[2010]" bal ^assets ^liabilities
 @end smallexample
 
@@ -7499,7 +7536,7 @@ $ ledger --forecast "d<[2010]" bal ^assets ^liabilities
 
 Ledger directly supports ``timelog'' entries, which have this form:
 
-@smallexample
+@smallexample @c input:validate
 i 2013/03/28 22:13:00 ACCOUNT[  PAYEE]
 o 2013/03/29 03:39:00
 @end smallexample
@@ -7556,7 +7593,7 @@ addition to a set of functions and variables.
 @c a display predicate that I use with the @command{balance} command:
 
 @c @smallexample
-@c ledger -d /^Liabilities/?T<0:UT>100 balance
+@c ledger -d '/^Liabilities/?T<0:UT>100' balance
 @c @end smallexample
 
 @c The effect is that account totals are displayed only if: 1) A
@@ -8453,7 +8490,7 @@ Ledger data exists in one of two forms: raw and cooked.  Raw objects are
 what you get from a traversal like the above, and represent exactly what
 was seen in the data file.  Consider this journal:
 
-@smallexample
+@smallexample @c input:validate
 = true
     (Assets:Cash)    $100
 
@@ -8464,7 +8501,7 @@ was seen in the data file.  Consider this journal:
 
 In this case, the @emph{raw} regular transaction in this file is:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-01 KFC
     Expenses:Food    $100
     Assets:Credit
@@ -8472,7 +8509,7 @@ In this case, the @emph{raw} regular transaction in this file is:
 
 While the @emph{cooked} form is:
 
-@smallexample
+@smallexample @c input:validate
 2012-03-01 KFC
     Expenses:Food    $100
     Assets:Credit   $-100
@@ -8813,7 +8850,7 @@ one or more @dfn{postings}, which describe how @dfn{amounts} flow from
 one @dfn{account} to another.  Here is an example of the simplest of
 journal files:
 
-@smallexample
+@smallexample @c input:validate
 2010/05/31 Just an example
     Expenses:Some:Account                $100.00
     Income:Another:Account
@@ -8837,7 +8874,7 @@ It is also typical, though not enforced, to think of the first posting
 as the destination, and the final as the source.  Thus, the amount of
 the first posting is typically positive.  Consider:
 
-@smallexample
+@smallexample @c input:validate
 2010/05/31 An income transaction
     Assets:Checking       $1,000.00
     Income:Salary
@@ -8885,7 +8922,7 @@ spaces between the end of the post and the beginning of the amount
 
 In the simplest form, bare decimal numbers are accepted:
 
-@smallexample
+@smallexample @c input:validate
 2010/05/31 An income transaction
     Assets:Checking        1000.00
     Income:Salary
@@ -8992,10 +9029,10 @@ amount for a posting.  But what if the amount you paid for something
 was in one commodity, and the amount received was another?  There are
 two main ways to express this:
 
-@smallexample
+@smallexample @c input:validate
 2010/05/31 Farmer's Market
     Assets:My Larder           100 apples
-    Assets:Checking                $20.00
+    Assets:Checking                -$20.00
 @end smallexample
 
 In this example, you have paid twenty dollars for one hundred apples.
@@ -9003,7 +9040,7 @@ The cost to you is twenty cents per apple, and Ledger calculates this
 implied cost for you.  You can also make the cost explicit using a
 @dfn{cost amount}:
 
-@smallexample
+@smallexample @c input:validate
 2010/05/31 Farmer's Market
     Assets:My Larder           100 apples @@ $0.200000
     Assets:Checking
@@ -9014,7 +9051,7 @@ amount; and since cost amount are @emph{unobserved}, the use of six
 decimal places has no effect on how dollar amounts are displayed in
 the final report.  You can also specify the @dfn{total cost}:
 
-@smallexample
+@smallexample @c input:validate
 2010/05/31 Farmer's Market
     Assets:My Larder           100 apples @@@@ $20
     Assets:Checking
@@ -9024,7 +9061,7 @@ These three forms have identical meaning.  In most cases the first is
 preferred, but the second two are necessary when more than two
 postings are involved:
 
-@smallexample
+@smallexample @c input:validate
 2010/05/31 Farmer's Market
     Assets:My Larder           100 apples        @@ $0.200000
     Assets:My Larder           100 pineapples    @@ $0.33
@@ -9047,10 +9084,10 @@ to buy and sells units of the other commodity.  In the fruit examples
 above, dollars are the primary commodity.  This is decided by Ledger
 on the placement of the commodity in the transaction:
 
-@smallexample
+@smallexample @c input:validate
 2010/05/31 Sample Transaction
     Expenses               100 secondary
-    Assets                  50 primary
+    Assets                  -50 primary
 
 2010/05/31 Sample Transaction
     Expenses               100 secondary @@ 0.5 primary
@@ -9387,7 +9424,7 @@ The following journal file is included with the source distribution of
 ledger.  It is called @file{drewr.dat} and exhibits many ledger
 features, include automatic and virtual transactions,
 
-@smallexample
+@smallexample @c input:validate
 ; -*- ledger -*-
 
 = /^Income/
@@ -9485,7 +9522,7 @@ $ ledger register Checking  --sort d  -d 'd>[2011/04/01]' until 2011/05/25
 @node Ledger Files,  , Invoking Ledger, Cookbook
 @subsection Ledger Files
 
-@smallexample
+@smallexample @c input:validate
 = /^Income:Taxable/
   (Liabilities:Tithe Owed)    -0.1
 = /Noah/
diff --git a/test/DocTests.py b/test/DocTests.py
index cc540aa9..d2931686 100755
--- a/test/DocTests.py
+++ b/test/DocTests.py
@@ -22,6 +22,7 @@ class DocTests:
     self.testin_token  = 'command'
     self.testout_token = 'output'
     self.testdat_token = 'input'
+    self.validate_token = 'validate'
     self.testwithdat_token = 'with_input'
 
   def read_example(self):
@@ -31,14 +32,14 @@ class DocTests:
       line = self.file.readline()
       self.current_line += 1
       if len(line) <= 0 or endexample.match(line): break
-      example += line
+      example += line.replace("@@","@").replace("@{","{").replace("@}","}")
     return example
 
   def test_id(self, example):
     return hashlib.sha1(example.rstrip()).hexdigest()[0:7].upper()
 
   def find_examples(self):
-    startexample = re.compile(r'^@smallexample\s+@c\s+(%s|%s|%s)(?::([\dA-Fa-f]+))?(?:,(.*))?'
+    startexample = re.compile(r'^@smallexample\s+@c\s+(%s|%s|%s)(?::([\dA-Fa-f]+|validate))?(?:,(.*))?'
         % (self.testin_token, self.testout_token, self.testdat_token))
     while True:
       line = self.file.readline()
@@ -67,10 +68,16 @@ class DocTests:
           test_id = self.test_id(example)
           if test_kind == self.testin_token:
             print >> sys.stderr, 'Use', self.test_id(example)
-        elif test_kind == self.testin_token and test_id != self.test_id(example):
+        elif test_kind == self.testin_token and test_id != self.validate_token and test_id != self.test_id(example):
           print >> sys.stderr, 'Expected test id', test_id, 'for example' \
               , test_kind, 'on line', test_begin_line, 'to be', self.test_id(example)
 
+        if test_id == self.validate_token:
+          test_id = "Val-" + str(test_begin_line)
+          if test_kind == self.testin_token:
+            test_kind = "validate-command"
+          elif test_kind == self.testdat_token:
+            test_kind = "validate-data"
         try:
           self.examples[test_id]
         except KeyError:
@@ -91,10 +98,17 @@ class DocTests:
             }
 
   def parse_command(self, test_id, example):
+    validate_command = False
     try:
       command = example[self.testin_token][self.testin_token]
     except KeyError:
-      return None
+      if 'validate-data' in example:
+        command = '$ ledger bal'
+      elif 'validate-command' in example:
+        validate_command = True
+        command = example['validate-command']['validate-command']
+      else:
+        return None
 
     command = command.rstrip().split()
     if command[0] == '$': command.remove('$')
@@ -110,12 +124,18 @@ class DocTests:
       except ValueError:
         findex = index+1
         command.insert(findex, '--file')
-        command.insert(findex+1, test_id + '.dat')
+        if validate_command:
+          command.insert(findex+1, 'sample.dat')
+        else:
+          command.insert(findex+1, test_id + '.dat')
     return (command, findex+1)
 
   def test_examples(self):
     failed = set()
     for test_id in self.examples:
+      validation = False
+      if "validate-data" in self.examples[test_id] or "validate-command" in self.examples[test_id]:
+        validation = True
       example = self.examples[test_id]
       try:
         (command, findex) = self.parse_command(test_id, example)
@@ -135,9 +155,12 @@ class DocTests:
           with_input = example[self.testin_token]['opts'][self.testwithdat_token]
           input = self.examples[with_input][self.testdat_token][self.testdat_token]
         except KeyError:
-          input = None
+          try:
+            input = example['validate-data']['validate-data']
+          except KeyError:
+            input = None
 
-      if command and output:
+      if command and (output or validation):
         test_file_created = False
         if findex:
           scriptpath = os.path.dirname(os.path.realpath(__file__))
@@ -150,11 +173,13 @@ class DocTests:
                 f.write(input)
             elif os.path.exists(test_input_dir + test_file):
               command[findex] = test_input_dir + test_file
+        error = False
         try:
           verify = subprocess.check_output(command)
         except:
           verify = str()
-        valid = (output == verify)
+          error = True
+        valid = (output == verify) or (not error and validation)
         if valid and test_file_created:
           os.remove(test_file)
         if self.verbose > 0:
@@ -166,9 +191,10 @@ class DocTests:
           failed.add(test_id)
           if self.verbose > 1:
             print ' '.join(command)
-            for line in unified_diff(output.split('\n'), verify.split('\n'), fromfile='generated', tofile='expected'):
-              print(line)
-            print
+            if not validation:
+              for line in unified_diff(output.split('\n'), verify.split('\n'), fromfile='generated', tofile='expected'):
+                print(line)
+              print
     if not self.verbose:
       print
     if len(failed) > 0: