pcretest
(1)
名称
pcretest - compatible regular
expressions.
用法概要
pcretest [options] [input file [output file]]
pcretest was written as a test program for the PCRE regular
expression library itself, but it can also be used for
experimenting with regular expressions. This document
describes the features of the test program; for details of
the regular expressions themselves, see the pcrepattern doc-
umentation. For details of the PCRE library function calls
and their options, see the pcreapi documentation. The input
for pcretest is a sequence of regular expression patterns
and strings to be matched, as described below. The output
shows the result of each match. Options on the command line
and the patterns control PCRE options and exactly what is
output.
描述
User Commands PCRETEST(1)
NAME
pcretest - a program for testing Perl-compatible regular
expressions.
SYNOPSIS
pcretest [options] [input file [output file]]
pcretest was written as a test program for the PCRE regular
expression library itself, but it can also be used for
experimenting with regular expressions. This document
describes the features of the test program; for details of
the regular expressions themselves, see the pcrepattern doc-
umentation. For details of the PCRE library function calls
and their options, see the pcreapi documentation. The input
for pcretest is a sequence of regular expression patterns
and strings to be matched, as described below. The output
shows the result of each match. Options on the command line
and the patterns control PCRE options and exactly what is
output.
COMMAND LINE OPTIONS
-b Behave as if each pattern has the /B (show byte
code) modifier; the internal form is output after
compilation.
-C Output the version number of the PCRE library, and
all available information about the optional fea-
tures that are included, and then exit.
-d Behave as if each pattern has the /D (debug) modi-
fier; the internal form and information about the
compiled pattern is output after compilation; -d
is equivalent to -b -i.
-dfa Behave as if each data line contains the \D escape
sequence; this causes the alternative matching
function, pcre_dfa_exec(), to be used instead of
the standard pcre_exec() function (more detail is
given below).
-help Output a brief summary these options and then
exit.
-i Behave as if each pattern has the /I modifier;
information about the compiled pattern is given
after compilation.
-M Behave as if each data line contains the \M escape
sequence; this causes PCRE to discover the minimum
MATCH_LIMIT and MATCH_LIMIT_RECURSION settings by
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calling pcre_exec() repeatedly with different lim-
its.
-m Output the size of each compiled pattern after it
has been compiled. This is equivalent to adding /M
to each regular expression.
-o osize Set the number of elements in the output vector
that is used when calling pcre_exec() or
pcre_dfa_exec() to be osize. The default value is
45, which is enough for 14 capturing subexpres-
sions for pcre_exec() or 22 different matches for
pcre_dfa_exec(). The vector size can be changed
for individual matching calls by including \O in
the data line (see below).
-p Behave as if each pattern has the /P modifier; the
POSIX wrapper API is used to call PCRE. None of
the other options has any effect when -p is set.
-q Do not output the version number of pcretest at
the start of execution.
-S size On Unix-like systems, set the size of the run-time
stack to size megabytes.
-s or -s+ Behave as if each pattern has the /S modifier; in
other words, force each pattern to be studied. If
-s+ is used, the PCRE_STUDY_JIT_COMPILE flag is
passed to pcre_study(), causing just-in-time opti-
mization to be set up if it is available. If the
/I or /D option is present on a pattern (request-
ing output about the compiled pattern), informa-
tion about the result of studying is not included
when studying is caused only by -s and neither -i
nor -d is present on the command line. This behav-
iour means that the output from tests that are run
with and without -s should be identical, except
when options that output information about the
actual running of a match are set. The -M, -t, and
-tm options, which give information about
resources used, are likely to produce different
output with and without -s. Output may also differ
if the /C option is present on an individual pat-
tern. This uses callouts to trace the the matching
process, and this may be different between studied
and non-studied patterns. If the pattern contains
(*MARK) items there may also be differences, for
the same reason. The -s command line option can be
overridden for specific patterns that should never
be studied (see the /S pattern modifier below).
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-t Run each compile, study, and match many times with
a timer, and output resulting time per compile or
match (in milliseconds). Do not set -m with -t,
because you will then get the size output a zil-
lion times, and the timing will be distorted. You
can control the number of iterations that are used
for timing by following -t with a number (as a
separate item on the command line). For example,
"-t 1000" would iterate 1000 times. The default is
to iterate 500000 times.
-tm This is like -t except that it times only the
matching phase, not the compile or study phases.
DESCRIPTION
If pcretest is given two filename arguments, it reads from
the first and writes to the second. If it is given only one
filename argument, it reads from that file and writes to
stdout. Otherwise, it reads from stdin and writes to stdout,
and prompts for each line of input, using "re>" to prompt
for regular expressions, and "data>" to prompt for data
lines.
When pcretest is built, a configuration option can specify
that it should be linked with the libreadline library. When
this is done, if the input is from a terminal, it is read
using the readline() function. This provides line-editing
and history facilities. The output from the -help option
states whether or not readline() will be used.
The program handles any number of sets of input on a single
input file. Each set starts with a regular expression, and
continues with any number of data lines to be matched
against the pattern.
Each data line is matched separately and independently. If
you want to do multi-line matches, you have to use the \n
escape sequence (or \r or \r\n, etc., depending on the new-
line setting) in a single line of input to encode the new-
line sequences. There is no limit on the length of data
lines; the input buffer is automatically extended if it is
too small.
An empty line signals the end of the data lines, at which
point a new regular expression is read. The regular expres-
sions are given enclosed in any non-alphanumeric delimiters
other than backslash, for example:
/(a|bc)x+yz/
White space before the initial delimiter is ignored. A
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regular expression may be continued over several input
lines, in which case the newline characters are included
within it. It is possible to include the delimiter within
the pattern by escaping it, for example
/abc\/def/
If you do so, the escape and the delimiter form part of the
pattern, but since delimiters are always non-alphanumeric,
this does not affect its interpretation. If the terminating
delimiter is immediately followed by a backslash, for exam-
ple,
/abc/\
then a backslash is added to the end of the pattern. This is
done to provide a way of testing the error condition that
arises if a pattern finishes with a backslash, because
/abc\/
is interpreted as the first line of a pattern that starts
with "abc/", causing pcretest to read the next line as a
continuation of the regular expression.
PATTERN MODIFIERS
A pattern may be followed by any number of modifiers, which
are mostly single characters. Following Perl usage, these
are referred to below as, for example, "the /i modifier",
even though the delimiter of the pattern need not always be
a slash, and no slash is used when writing modifiers. White
space may appear between the final pattern delimiter and the
first modifier, and between the modifiers themselves.
The /i, /m, /s, and /x modifiers set the PCRE_CASELESS,
PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options,
respectively, when pcre_compile() is called. These four mod-
ifier letters have the same effect as they do in Perl. For
example:
/caseless/i
The following table shows additional modifiers for setting
PCRE compile-time options that do not correspond to anything
in Perl:
/8 PCRE_UTF8
/? PCRE_NO_UTF8_CHECK
/A PCRE_ANCHORED
/C PCRE_AUTO_CALLOUT
/E PCRE_DOLLAR_ENDONLY
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/f PCRE_FIRSTLINE
/J PCRE_DUPNAMES
/N PCRE_NO_AUTO_CAPTURE
/U PCRE_UNGREEDY
/W PCRE_UCP
/X PCRE_EXTRA
/Y PCRE_NO_START_OPTIMIZE
/<JS> PCRE_JAVASCRIPT_COMPAT
/<cr> PCRE_NEWLINE_CR
/<lf> PCRE_NEWLINE_LF
/<crlf> PCRE_NEWLINE_CRLF
/<anycrlf> PCRE_NEWLINE_ANYCRLF
/<any> PCRE_NEWLINE_ANY
/<bsr_anycrlf> PCRE_BSR_ANYCRLF
/<bsr_unicode> PCRE_BSR_UNICODE
The modifiers that are enclosed in angle brackets are lit-
eral strings as shown, including the angle brackets, but the
letters within can be in either case. This example sets
multiline matching with CRLF as the line ending sequence:
/^abc/m<CRLF>
As well as turning on the PCRE_UTF8 option, the /8 modifier
also causes any non-printing characters in output strings to
be printed using the \x{hh...} notation if they are valid
UTF-8 sequences. Full details of the PCRE options are given
in the pcreapi documentation.
Finding all matches in a string
Searching for all possible matches within each subject
string can be requested by the /g or /G modifier. After
finding a match, PCRE is called again to search the remain-
der of the subject string. The difference between /g and /G
is that the former uses the startoffset argument to
pcre_exec() to start searching at a new point within the
entire string (which is in effect what Perl does), whereas
the latter passes over a shortened substring. This makes a
difference to the matching process if the pattern begins
with a lookbehind assertion (including \b or \B).
If any call to pcre_exec() in a /g or /G sequence matches an
empty string, the next call is done with the
PCRE_NOTEMPTY_ATSTART and PCRE_ANCHORED flags set in order
to search for another, non-empty, match at the same point.
If this second match fails, the start offset is advanced,
and the normal match is retried. This imitates the way Perl
handles such cases when using the /g modifier or the split()
function. Normally, the start offset is advanced by one
character, but if the newline convention recognizes CRLF as
a newline, and the current character is CR followed by LF,
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an advance of two is used.
Other modifiers
There are yet more modifiers for controlling the way
pcretest operates.
The /+ modifier requests that as well as outputting the sub-
string that matched the entire pattern, pcretest should in
addition output the remainder of the subject string. This is
useful for tests where the subject contains multiple copies
of the same substring. If the + modifier appears twice, the
same action is taken for captured substrings. In each case
the remainder is output on the following line with a plus
character following the capture number. Note that this modi-
fier must not immediately follow the /S modifier because /S+
has another meaning.
The /= modifier requests that the values of all potential
captured parentheses be output after a match by pcre_exec().
By default, only those up to the highest one actually used
in the match are output (corresponding to the return code
from pcre_exec()). Values in the offsets vector correspond-
ing to higher numbers should be set to -1, and these are
output as "<unset>". This modifier gives a way of checking
that this is happening.
The /B modifier is a debugging feature. It requests that
pcretest output a representation of the compiled byte code
after compilation. Normally this information contains length
and offset values; however, if /Z is also present, this data
is replaced by spaces. This is a special feature for use in
the automatic test scripts; it ensures that the same output
is generated for different internal link sizes.
The /D modifier is a PCRE debugging feature, and is equiva-
lent to /BI, that is, both the /B and the /I modifiers.
The /F modifier causes pcretest to flip the byte order of
the fields in the compiled pattern that contain 2-byte and
4-byte numbers. This facility is for testing the feature in
PCRE that allows it to execute patterns that were compiled
on a host with a different endianness. This feature is not
available when the POSIX interface to PCRE is being used,
that is, when the /P pattern modifier is specified. See also
the section about saving and reloading compiled patterns
below.
The /I modifier requests that pcretest output information
about the compiled pattern (whether it is anchored, has a
fixed first character, and so on). It does this by calling
pcre_fullinfo() after compiling a pattern. If the pattern is
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studied, the results of that are also output.
The /K modifier requests pcretest to show names from back-
tracking control verbs that are returned from calls to
pcre_exec(). It causes pcretest to create a pcre_extra block
if one has not already been created by a call to
pcre_study(), and to set the PCRE_EXTRA_MARK flag and the
mark field within it, every time that pcre_exec() is called.
If the variable that the mark field points to is non-NULL
for a match, non-match, or partial match, pcretest prints
the string to which it points. For a match, this is shown on
a line by itself, tagged with "MK:". For a non-match it is
added to the message.
The /L modifier must be followed directly by the name of a
locale, for example,
/pattern/Lfr_FR
For this reason, it must be the last modifier. The given
locale is set, pcre_maketables() is called to build a set of
character tables for the locale, and this is then passed to
pcre_compile() when compiling the regular expression. With-
out an /L (or /T) modifier, NULL is passed as the tables
pointer; that is, /L applies only to the expression on which
it appears.
The /M modifier causes the size of memory block used to hold
the compiled pattern to be output. This does not include the
size of the pcre block; it is just the actual compiled data.
If the pattern is successfully studied with the
PCRE_STUDY_JIT_COMPILE option, the size of the JIT compiled
code is also output.
If the /S modifier appears once, it causes pcre_study() to
be called after the expression has been compiled, and the
results used when the expression is matched. If /S appears
twice, it suppresses studying, even if it was requested
externally by the -s command line option. This makes it pos-
sible to specify that certain patterns are always studied,
and others are never studied, independently of -s. This fea-
ture is used in the test files in a few cases where the out-
put is different when the pattern is studied.
If the /S modifier is immediately followed by a + character,
the call to pcre_study() is made with the
PCRE_STUDY_JIT_COMPILE option, requesting just-in-time opti-
mization support if it is available. Note that there is also
a /+ modifier; it must not be given immediately after /S
because this will be misinterpreted. If JIT studying is suc-
cessful, it will automatically be used when pcre_exec() is
run, except when incompatible run-time options are
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specified. These include the partial matching options; a
complete list is given in the pcrejit documentation. See
also the \J escape sequence below for a way of setting the
size of the JIT stack.
The /T modifier must be followed by a single digit. It
causes a specific set of built-in character tables to be
passed to pcre_compile(). It is used in the standard PCRE
tests to check behaviour with different character tables.
The digit specifies the tables as follows:
0 the default ASCII tables, as distributed in
pcre_chartables.c.dist
1 a set of tables defining ISO 8859 characters
In table 1, some characters whose codes are greater than 128
are identified as letters, digits, spaces, etc.
Using the POSIX wrapper API
The /P modifier causes pcretest to call PCRE via the POSIX
wrapper API rather than its native API. When /P is set, the
following modifiers set options for the regcomp() function:
/i REG_ICASE
/m REG_NEWLINE
/N REG_NOSUB
/s REG_DOTALL )
/U REG_UNGREEDY ) These options are not part of
/W REG_UCP ) the POSIX standard
/8 REG_UTF8 )
The /+ modifier works as described above. All other modi-
fiers are ignored.
DATA LINES
Before each data line is passed to pcre_exec(), leading and
trailing white space is removed, and it is then scanned for
\ escapes. Some of these are pretty esoteric features,
intended for checking out some of the more complicated fea-
tures of PCRE. If you are just testing "ordinary" regular
expressions, you probably don't need any of these. The fol-
lowing escapes are recognized:
\a alarm (BEL, \x07)
\b backspace (\x08)
\e escape (\x27)
\f form feed (\x0c)
\n newline (\x0a)
\qdd set the PCRE_MATCH_LIMIT limit to dd
(any number of digits)
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\r carriage return (\x0d)
\t tab (\x09)
\v vertical tab (\x0b)
\nnn octal character (up to 3 octal digits)
always a byte unless > 255 in UTF-8 mode
\xhh hexadecimal byte (up to 2 hex digits)
\x{hh...} hexadecimal character, any number of digits
in UTF-8 mode
\A pass the PCRE_ANCHORED option to pcre_exec()
or pcre_dfa_exec()
\B pass the PCRE_NOTBOL option to pcre_exec()
or pcre_dfa_exec()
\Cdd call pcre_copy_substring() for substring dd
after a successful match (number less than
32)
\Cname call pcre_copy_named_substring() for substring
"name" after a successful match (name termin-
ated by next non alphanumeric character)
\C+ show the current captured substrings at callout
time
\C- do not supply a callout function
\C!n return 1 instead of 0 when callout number n is
reached
\C!n!m return 1 instead of 0 when callout number n is
reached for the nth time
\C*n pass the number n (may be negative) as callout
data; this is used as the callout return
value
\D use the pcre_dfa_exec() match function
\F only shortest match for pcre_dfa_exec()
\Gdd call pcre_get_substring() for substring dd
after a successful match (number less than
32)
\Gname call pcre_get_named_substring() for substring
"name" after a successful match (name termin-
ated by next non-alphanumeric character)
\Jdd set up a JIT stack of dd kilobytes maximum (any
number of digits)
\L call pcre_get_substringlist() after a
successful match
\M discover the minimum MATCH_LIMIT and
MATCH_LIMIT_RECURSION settings
\N pass the PCRE_NOTEMPTY option to pcre_exec()
or pcre_dfa_exec(); if used twice, pass the
PCRE_NOTEMPTY_ATSTART option
\Odd set the size of the output vector passed to
pcre_exec() to dd (any number of digits)
\P pass the PCRE_PARTIAL_SOFT option to
pcre_exec()
or pcre_dfa_exec(); if used twice, pass the
PCRE_PARTIAL_HARD option
\Qdd set the PCRE_MATCH_LIMIT_RECURSION limit to dd
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(any number of digits)
\R pass the PCRE_DFA_RESTART option to
pcre_dfa_exec()
\S output details of memory get/free calls during
matching
\Y pass the PCRE_NO_START_OPTIMIZE option to
pcre_exec()
or pcre_dfa_exec()
\Z pass the PCRE_NOTEOL option to pcre_exec()
or pcre_dfa_exec()
\? pass the PCRE_NO_UTF8_CHECK option to
pcre_exec() or pcre_dfa_exec()
\>dd start the match at offset dd (optional "-";
then
any number of digits); this sets the
startoffset
argument for pcre_exec() or pcre_dfa_exec()
\<cr> pass the PCRE_NEWLINE_CR option to pcre_exec()
or pcre_dfa_exec()
\<lf> pass the PCRE_NEWLINE_LF option to pcre_exec()
or pcre_dfa_exec()
\<crlf> pass the PCRE_NEWLINE_CRLF option to
pcre_exec()
or pcre_dfa_exec()
\<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to
pcre_exec()
or pcre_dfa_exec()
\<any> pass the PCRE_NEWLINE_ANY option to pcre_exec()
or pcre_dfa_exec()
Note that \xhh always specifies one byte, even in UTF-8
mode; this makes it possible to construct invalid UTF-8
sequences for testing purposes. On the other hand, \x{hh} is
interpreted as a UTF-8 character in UTF-8 mode, generating
more than one byte if the value is greater than 127. When
not in UTF-8 mode, it generates one byte for values less
than 256, and causes an error for greater values.
The escapes that specify line ending sequences are literal
strings, exactly as shown. No more than one newline setting
should be present in any data line.
A backslash followed by anything else just escapes the any-
thing else. If the very last character is a backslash, it is
ignored. This gives a way of passing an empty line as data,
since a real empty line terminates the data input.
The \J escape provides a way of setting the maximum stack
size that is used by the just-in-time optimization code. It
is ignored if JIT optimization is not being used. Providing
a stack that is larger than the default 32K is necessary
only for very complicated patterns.
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If \M is present, pcretest calls pcre_exec() several times,
with different values in the match_limit and
match_limit_recursion fields of the pcre_extra data struc-
ture, until it finds the minimum numbers for each parameter
that allow pcre_exec() to complete without error. Because
this is testing a specific feature of the normal interpre-
tive pcre_exec() execution, the use of any JIT optimization
that might have been set up by the /S+ qualifier of -s+
option is disabled.
The match_limit number is a measure of the amount of back-
tracking that takes place, and checking it out can be
instructive. For most simple matches, the number is quite
small, but for patterns with very large numbers of matching
possibilities, it can become large very quickly with
increasing length of subject string. The match_limit_recur-
sion number is a measure of how much stack (or, if PCRE is
compiled with NO_RECURSE, how much heap) memory is needed to
complete the match attempt.
When \O is used, the value specified may be higher or lower
than the size set by the -O command line option (or
defaulted to 45); \O applies only to the call of pcre_exec()
for the line in which it appears.
If the /P modifier was present on the pattern, causing the
POSIX wrapper API to be used, the only option-setting
sequences that have any effect are \B, \N, and \Z, causing
REG_NOTBOL, REG_NOTEMPTY, and REG_NOTEOL, respectively, to
be passed to regexec().
The use of \x{hh...} to represent UTF-8 characters is not
dependent on the use of the /8 modifier on the pattern. It
is recognized always. There may be any number of hexadecimal
digits inside the braces. The result is from one to six
bytes, encoded according to the original UTF-8 rules of RFC
2279. This allows for values in the range 0 to 0x7FFFFFFF.
Note that not all of those are valid Unicode code points, or
indeed valid UTF-8 characters according to the later rules
in RFC 3629.
THE ALTERNATIVE MATCHING FUNCTION
By default, pcretest uses the standard PCRE matching func-
tion, pcre_exec() to match each data line. From release 6.0,
PCRE supports an alternative matching function,
pcre_dfa_test(), which operates in a different way, and has
some restrictions. The differences between the two functions
are described in the pcrematching documentation.
If a data line contains the \D escape sequence, or if the
command line contains the -dfa option, the alternative
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matching function is called. This function finds all possi-
ble matches at a given point. If, however, the \F escape
sequence is present in the data line, it stops after the
first match is found. This is always the shortest possible
match.
DEFAULT OUTPUT FROM PCRETEST
This section describes the output when the normal matching
function, pcre_exec(), is being used.
When a match succeeds, pcretest outputs the list of captured
substrings that pcre_exec() returns, starting with number 0
for the string that matched the whole pattern. Otherwise, it
outputs "No match" when the return is PCRE_ERROR_NOMATCH,
and "Partial match:" followed by the partially matching sub-
string when pcre_exec() returns PCRE_ERROR_PARTIAL. (Note
that this is the entire substring that was inspected during
the partial match; it may include characters before the
actual match start if a lookbehind assertion, \K, \b, or \B
was involved.) For any other return, pcretest outputs the
PCRE negative error number and a short descriptive phrase.
If the error is a failed UTF-8 string check, the byte offset
of the start of the failing character and the reason code
are also output, provided that the size of the output vector
is at least two. Here is an example of an interactive
pcretest run.
$ pcretest
PCRE version 8.13 2011-04-30
re> /^abc(\d+)/
data> abc123
0: abc123
1: 123
data> xyz
No match
Unset capturing substrings that are not followed by one that
is set are not returned by pcre_exec(), and are not shown by
pcretest. In the following example, there are two capturing
substrings, but when the first data line is matched, the
second, unset substring is not shown. An "internal" unset
substring is shown as "<unset>", as for the second data
line.
re> /(a)|(b)/
data> a
0: a
1: a
data> b
0: b
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1: <unset>
2: b
If the strings contain any non-printing characters, they are
output as \0x escapes, or as \x{...} escapes if the /8 modi-
fier was present on the pattern. See below for the defini-
tion of non-printing characters. If the pattern has the /+
modifier, the output for substring 0 is followed by the the
rest of the subject string, identified by "0+" like this:
re> /cat/+
data> cataract
0: cat
0+ aract
If the pattern has the /g or /G modifier, the results of
successive matching attempts are output in sequence, like
this:
re> /\Bi(\w\w)/g
data> Mississippi
0: iss
1: ss
0: iss
1: ss
0: ipp
1: pp
"No match" is output only if the first match attempt fails.
Here is an example of a failure message (the offset 4 that
is specified by \>4 is past the end of the subject string):
re> /xyz/
data> xyz\>4
Error -24 (bad offset value)
If any of the sequences \C, \G, or \L are present in a data
line that is successfully matched, the substrings extracted
by the convenience functions are output with C, G, or L
after the string number instead of a colon. This is in addi-
tion to the normal full list. The string length (that is,
the return from the extraction function) is given in paren-
theses after each string for \C and \G.
Note that whereas patterns can be continued over several
lines (a plain ">" prompt is used for continuations), data
lines may not. However newlines can be included in data by
means of the \n escape (or \r, \r\n, etc., depending on the
newline sequence setting).
OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION
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When the alternative matching function, pcre_dfa_exec(), is
used (by means of the \D escape sequence or the -dfa command
line option), the output consists of a list of all the
matches that start at the first point in the subject where
there is at least one match. For example:
re> /(tang|tangerine|tan)/
data> yellow tangerine\D
0: tangerine
1: tang
2: tan
(Using the normal matching function on this data finds only
"tang".) The longest matching string is always given first
(and numbered zero). After a PCRE_ERROR_PARTIAL return, the
output is "Partial match:", followed by the partially match-
ing substring. (Note that this is the entire substring that
was inspected during the partial match; it may include char-
acters before the actual match start if a lookbehind asser-
tion, \K, \b, or \B was involved.)
If /g is present on the pattern, the search for further
matches resumes at the end of the longest match. For exam-
ple:
re> /(tang|tangerine|tan)/g
data> yellow tangerine and tangy sultana\D
0: tangerine
1: tang
2: tan
0: tang
1: tan
0: tan
Since the matching function does not support substring cap-
ture, the escape sequences that are concerned with captured
substrings are not relevant.
RESTARTING AFTER A PARTIAL MATCH
When the alternative matching function has given the
PCRE_ERROR_PARTIAL return, indicating that the subject par-
tially matched the pattern, you can restart the match with
additional subject data by means of the \R escape sequence.
For example:
re>
/^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
data> 23ja\P\D
Partial match: 23ja
data> n05\R\D
0: n05
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For further information about partial matching, see the
pcrepartial documentation.
CALLOUTS
If the pattern contains any callout requests, pcretest's
callout function is called during matching. This works with
both matching functions. By default, the called function
displays the callout number, the start and current positions
in the text at the callout time, and the next pattern item
to be tested. For example, the output
--->pqrabcdef
0 ^ ^ \d
indicates that callout number 0 occurred for a match attempt
starting at the fourth character of the subject string, when
the pointer was at the seventh character of the data, and
when the next pattern item was \d. Just one circumflex is
output if the start and current positions are the same.
Callouts numbered 255 are assumed to be automatic callouts,
inserted as a result of the /C pattern modifier. In this
case, instead of showing the callout number, the offset in
the pattern, preceded by a plus, is output. For example:
re> /\d?[A-E]\*/C
data> E*
--->E*
+0 ^ \d?
+3 ^ [A-E]
+8 ^^ \*
+10 ^ ^
0: E*
If a pattern contains (*MARK) items, an additional line is
output whenever a change of latest mark is passed to the
callout function. For example:
re> /a(*MARK:X)bc/C
data> abc
--->abc
+0 ^ a
+1 ^^ (*MARK:X)
+10 ^^ b
Latest Mark: X
+11 ^ ^ c
+12 ^ ^
0: abc
The mark changes between matching "a" and "b", but stays the
same for the rest of the match, so nothing more is output.
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If, as a result of backtracking, the mark reverts to being
unset, the text "<unset>" is output.
The callout function in pcretest returns zero (carry on
matching) by default, but you can use a \C item in a data
line (as described above) to change this and other parame-
ters of the callout.
Inserting callouts can be helpful when using pcretest to
check complicated regular expressions. For further informa-
tion about callouts, see the pcrecallout documentation.
NON-PRINTING CHARACTERS
When pcretest is outputting text in the compiled version of
a pattern, bytes other than 32-126 are always treated as
non-printing characters are are therefore shown as hex
escapes.
When pcretest is outputting text that is a matched part of a
subject string, it behaves in the same way, unless a differ-
ent locale has been set for the pattern (using the /L modi-
fier). In this case, the isprint() function to distinguish
printing and non-printing characters.
SAVING AND RELOADING COMPILED PATTERNS
The facilities described in this section are not available
when the POSIX interface to PCRE is being used, that is,
when the /P pattern modifier is specified.
When the POSIX interface is not in use, you can cause
pcretest to write a compiled pattern to a file, by following
the modifiers with > and a file name. For example:
/pattern/im >/some/file
See the pcreprecompile documentation for a discussion about
saving and re-using compiled patterns. Note that if the
pattern was successfully studied with JIT optimization, the
JIT data cannot be saved.
The data that is written is binary. The first eight bytes
are the length of the compiled pattern data followed by the
length of the optional study data, each written as four
bytes in big-endian order (most significant byte first). If
there is no study data (either the pattern was not studied,
or studying did not return any data), the second length is
zero. The lengths are followed by an exact copy of the com-
piled pattern. If there is additional study data, this
(excluding any JIT data) follows immediately after the com-
piled pattern. After writing the file, pcretest expects to
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read a new pattern.
A saved pattern can be reloaded into pcretest by specifying
< and a file name instead of a pattern. The name of the file
must not contain a < character, as otherwise pcretest will
interpret the line as a pattern delimited by < characters.
For example:
re> </some/file
Compiled pattern loaded from /some/file
No study data
If the pattern was previously studied with the JIT optimiza-
tion, the JIT information cannot be saved and restored, and
so is lost. When the pattern has been loaded, pcretest pro-
ceeds to read data lines in the usual way.
You can copy a file written by pcretest to a different host
and reload it there, even if the new host has opposite endi-
anness to the one on which the pattern was compiled. For
example, you can compile on an i86 machine and run on a
SPARC machine.
File names for saving and reloading can be absolute or rela-
tive, but note that the shell facility of expanding a file
name that starts with a tilde (~) is not available.
The ability to save and reload files in pcretest is intended
for testing and experimentation. It is not intended for pro-
duction use because only a single pattern can be written to
a file. Furthermore, there is no facility for supplying cus-
tom character tables for use with a reloaded pattern. If the
original pattern was compiled with custom tables, an attempt
to match a subject string using a reloaded pattern is likely
to cause pcretest to crash. Finally, if you attempt to load
a file that is not in the correct format, the result is
undefined.
ATTRIBUTES
See attributes(5) for descriptions of the following
attributes:
+---------------+------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+------------------+
|Availability | library/pcre |
+---------------+------------------+
|Stability | Uncommitted |
+---------------+------------------+
SEE ALSO
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User Commands PCRETEST(1)
pcre(3), pcreapi(3), pcrecallout(3), pcrejit, pcrematch-
ing(3), pcrepartial(d), pcrepattern(3), pcreprecompile(3).
AUTHOR
Philip Hazel
University Computing Service
Cambridge CB2 3QH, England.
REVISION
Last updated: 02 December 2011
Copyright (c) 1997-2011 University of Cambridge.
NOTES
This software was built from source available at
https://java.net/projects/solaris-userland. The original
community source was downloaded from http://source-
forge.net/projects/pcre/files/pcre/8.21/pcre-8.21.tar.gz
Further information about this software can be found on the
open source community website at http://pcre.org/.
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