PCRETEST(1) PCRETEST(1)
-
NAME
pcretest - a program for testing Perl-compatible regular expressions.
+
SYNOPSIS
- pcretest [-C] [-d] [-dfa] [-i] [-m] [-o osize] [-p] [-t] [source]
- [destination]
+ pcretest [options] [source] [destination]
pcretest was written as a test program for the PCRE regular expression
library itself, but it can also be used for experimenting with regular
per 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 runtime stack to
+ size megabytes.
+
-t Run each compile, study, and match many times with a timer,
and output resulting time per compile or match (in millisec-
onds). Do not set -m with -t, because you will then get the
ber of data lines to be matched against the pattern.
Each data line is matched separately and independently. If you want to
- do multiple-line matches, you have to use the \n escape sequence in a
- single line of input to encode the newline characters. The maximum
- length of data line is 30,000 characters.
+ do multi-line matches, you have to use the \n escape sequence (or \r or
+ \r\n, depending on the newline setting) in a single line of input to
+ encode the newline characters. 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 expressions are given enclosed
- in any non-alphanumeric delimiters other than backslash, for example
+ An empty line signals the end of the data lines, at which point a new
+ regular expression is read. The regular expressions 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 regular expres-
- sion may be continued over several input lines, in which case the new-
- line characters are included within it. It is possible to include the
+ White space before the initial delimiter is ignored. A regular expres-
+ sion may be continued over several input lines, in which case the new-
+ line 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 fol-
+ 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 fol-
lowed by a backslash, for example,
/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
+ 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/",
+ 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. Whitespace may appear between the final pattern delimiter
+ 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. Whitespace 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_com-
- pile() is called. These four modifier letters have the same effect as
+ PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when pcre_com-
+ pile() is called. These four modifier letters have the same effect as
they do in Perl. For example:
/caseless/i
The following table shows additional modifiers for setting PCRE options
that do not correspond to anything in Perl:
- /A PCRE_ANCHORED
- /C PCRE_AUTO_CALLOUT
- /E PCRE_DOLLAR_ENDONLY
- /f PCRE_FIRSTLINE
- /N PCRE_NO_AUTO_CAPTURE
- /U PCRE_UNGREEDY
- /X PCRE_EXTRA
-
- Searching for all possible matches within each subject string can be
- requested by the /g or /G modifier. After finding a match, PCRE is
+ /A PCRE_ANCHORED
+ /C PCRE_AUTO_CALLOUT
+ /E PCRE_DOLLAR_ENDONLY
+ /f PCRE_FIRSTLINE
+ /J PCRE_DUPNAMES
+ /N PCRE_NO_AUTO_CAPTURE
+ /U PCRE_UNGREEDY
+ /X PCRE_EXTRA
+ /<cr> PCRE_NEWLINE_CR
+ /<lf> PCRE_NEWLINE_LF
+ /<crlf> PCRE_NEWLINE_CRLF
+
+ Those specifying line endings are literal strings as shown. Details of
+ the meanings of these PCRE options are given in the pcreapi documenta-
+ tion.
+
+ 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 remainder of the subject string. The differ-
ence 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
+ 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 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 by
- one, and the normal match is retried. This imitates the way Perl han-
+ 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 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 by
+ one, and the normal match is retried. This imitates the way Perl han-
dles such cases when using the /g modifier or the split() function.
+ Other modifiers
+
There are yet more modifiers for controlling the way pcretest operates.
- The /+ modifier requests that as well as outputting the substring that
- matched the entire pattern, pcretest should in addition output the
- remainder of the subject string. This is useful for tests where the
+ The /+ modifier requests that as well as outputting the substring 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.
- The /L modifier must be followed directly by the name of a locale, for
+ 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. Without an /L modifier, NULL is passed as the
- tables pointer; that is, /L applies only to the expression on which it
+ 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. Without an /L modifier, NULL is passed as the
+ tables pointer; that is, /L applies only to the expression on which it
appears.
- 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 studied, the results of that are also out-
+ 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 studied, the results of that are also out-
put.
The /D modifier is a PCRE debugging feature, which also assumes /I. It
- causes the internal form of compiled regular expressions to be output
+ causes the internal form of compiled regular expressions to be output
after compilation. If the pattern was studied, the information returned
is also output.
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
+ 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
+ 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 /S modifier causes pcre_study() to be called after the expression
+ The /S modifier causes pcre_study() to be called after the expression
has been compiled, and the results used when the expression is matched.
- The /M modifier causes the size of memory block used to hold the com-
+ The /M modifier causes the size of memory block used to hold the com-
piled pattern to be output.
- The /P modifier causes pcretest to call PCRE via the POSIX wrapper API
- rather than its native API. When this is done, all other modifiers
- except /i, /m, and /+ are ignored. REG_ICASE is set if /i is present,
- and REG_NEWLINE is set if /m is present. The wrapper functions force
- PCRE_DOLLAR_ENDONLY always, and PCRE_DOTALL unless REG_NEWLINE is set.
+ The /P modifier causes pcretest to call PCRE via the POSIX wrapper API
+ rather than its native API. When this is done, all other modifiers
+ except /i, /m, and /+ are ignored. REG_ICASE is set if /i is present,
+ and REG_NEWLINE is set if /m is present. The wrapper functions force
+ PCRE_DOLLAR_ENDONLY always, and PCRE_DOTALL unless REG_NEWLINE is set.
- The /8 modifier causes pcretest to call PCRE with the PCRE_UTF8 option
- set. This turns on support for UTF-8 character handling in PCRE, pro-
- vided that it was compiled with this support enabled. This modifier
+ The /8 modifier causes pcretest to call PCRE with the PCRE_UTF8 option
+ set. This turns on support for UTF-8 character handling in PCRE, pro-
+ vided that it was compiled with this support enabled. This 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.
- If the /? modifier is used with /8, it causes pcretest to call
- pcre_compile() with the PCRE_NO_UTF8_CHECK option, to suppress the
+ If the /? modifier is used with /8, it causes pcretest to call
+ pcre_compile() with the PCRE_NO_UTF8_CHECK option, to suppress the
checking of the string for UTF-8 validity.
DATA LINES
- Before each data line is passed to pcre_exec(), leading and trailing
- whitespace 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 features of PCRE. If you are just testing "ordi-
- nary" regular expressions, you probably don't need any of these. The
+ Before each data line is passed to pcre_exec(), leading and trailing
+ whitespace 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 features of PCRE. If you are just testing "ordi-
+ nary" regular expressions, you probably don't need any of these. The
following escapes are recognized:
\a alarm (= BEL)
\e escape
\f formfeed
\n newline
+ \qdd set the PCRE_MATCH_LIMIT limit to dd
+ (any number of digits)
\r carriage return
\t tab
\v vertical tab
\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
ated by next non-alphanumeric character)
\L call pcre_get_substringlist() after a
successful match
- \M discover the minimum MATCH_LIMIT setting
+ \M discover the minimum MATCH_LIMIT and
+ MATCH_LIMIT_RECURSION settings
\N pass the PCRE_NOTEMPTY option to pcre_exec()
+ or pcre_dfa_exec()
\Odd set the size of the output vector passed to
pcre_exec() to dd (any number of digits)
\P pass the PCRE_PARTIAL option to pcre_exec()
or pcre_dfa_exec()
+ \Qdd set the PCRE_MATCH_LIMIT_RECURSION limit to dd
+ (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
\Z pass the PCRE_NOTEOL option to pcre_exec()
+ or pcre_dfa_exec()
\? pass the PCRE_NO_UTF8_CHECK option to
- pcre_exec()
+ pcre_exec() or pcre_dfa_exec()
\>dd start the match at offset dd (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()
- A backslash followed by anything else just escapes the anything 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 termi-
- nates the data input.
+ The escapes that specify line endings are literal strings, exactly as
+ shown. A backslash followed by anything else just escapes the anything
+ 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.
If \M is present, pcretest calls pcre_exec() several times, with dif-
- ferent values in the match_limit field of the pcre_extra data struc-
- ture, until it finds the minimum number that is needed for pcre_exec()
- to complete. This number is a measure of the amount of recursion and
- backtracking 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.
-
- When \O is used, the value specified may be higher or lower than the
+ ferent values in the match_limit and match_limit_recursion fields of
+ the pcre_extra data structure, until it finds the minimum numbers for
+ each parameter that allow pcre_exec() to complete. The match_limit num-
+ ber is a measure of the amount of backtracking 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_recursion 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 wrap-
- per API to be used, only \B and \Z have any effect, causing REG_NOTBOL
- and REG_NOTEOL to be passed to regexec() respectively.
+ If the /P modifier was present on the pattern, causing the POSIX wrap-
+ per API to be used, the only option-setting sequences that have any
+ effect are \B and \Z, causing REG_NOTBOL 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.
Note that while patterns can be continued over several lines (a plain
">" prompt is used for continuations), data lines may not. However new-
- lines can be included in data by means of the \n escape.
+ lines can be included in data by means of the \n escape (or \r or \r\n
+ for those newline settings).
OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION
- 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
+ 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)/
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).
+ (Using the normal matching function on this data finds only "tang".)
+ The longest matching string is always given first (and numbered zero).
- If /gP is present on the pattern, the search for further matches
+ If /gP is present on the pattern, the search for further matches
resumes at the end of the longest match. For example:
re> /(tang|tangerine|tan)/g
1: tan
0: tan
- Since the matching function does not support substring capture, the
- escape sequences that are concerned with captured substrings are not
+ Since the matching function does not support substring capture, 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 partially matched the pattern, you
- can restart the match with additional subject data by means of the \R
+ return, indicating that the subject partially matched the pattern, you
+ can restart the match with additional subject data by means of the \R
escape sequence. For example:
re> /^?(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)$/
data> n05\R\D
0: n05
- For further information about partial matching, see the pcrepartial
+ For further information about partial matching, see the pcrepartial
documentation.
CALLOUTS
- If the pattern contains any callout requests, pcretest's callout func-
- tion is called during matching. This works with both matching func-
+ If the pattern contains any callout requests, pcretest's callout func-
+ tion is called during matching. This works with both matching func-
tions. By default, the called function displays the callout number, the
- start and current positions in the text at the callout time, and 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
+ 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
+ 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
+10 ^ ^
0: E*
- 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)
+ 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.
- Inserting callouts can be helpful when using pcretest to check compli-
- cated regular expressions. For further information about callouts, see
+ Inserting callouts can be helpful when using pcretest to check compli-
+ cated regular expressions. For further information about callouts, see
the pcrecallout documentation.
SAVING AND RELOADING COMPILED PATTERNS
- The facilities described in this section are not available when the
+ The facilities described in this section are not available when the
POSIX inteface to PCRE is being used, that is, when the /P pattern mod-
ifier 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
+ 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
+ See the pcreprecompile documentation for a discussion about saving and
re-using compiled patterns.
- 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
+ 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 sec-
- ond length is zero. The lengths are followed by an exact copy of the
+ ond length is zero. The lengths are followed by an exact copy of the
compiled pattern. If there is additional study data, this follows imme-
- diately after the compiled pattern. After writing the file, pcretest
+ diately after the compiled pattern. After writing the file, pcretest
expects to read a new pattern.
A saved pattern can be reloaded into pcretest by specifing < 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
+ 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 regex loaded from /some/file
No study data
- When the pattern has been loaded, pcretest proceeds to read data lines
+ When the pattern has been loaded, pcretest proceeds 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 endianness to the one on
- which the pattern was compiled. For example, you can compile on an i86
+ You can copy a file written by pcretest to a different host and reload
+ it there, even if the new host has opposite endianness 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 relative, but
- note that the shell facility of expanding a file name that starts with
+ File names for saving and reloading can be absolute or relative, 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 test-
- ing and experimentation. It is not intended for production use because
- only a single pattern can be written to a file. Furthermore, there is
- no facility for supplying custom 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
+ The ability to save and reload files in pcretest is intended for test-
+ ing and experimentation. It is not intended for production use because
+ only a single pattern can be written to a file. Furthermore, there is
+ no facility for supplying custom 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.
University Computing Service,
Cambridge CB2 3QG, England.
-Last updated: 28 February 2005
-Copyright (c) 1997-2005 University of Cambridge.
+Last updated: 29 June 2006
+Copyright (c) 1997-2006 University of Cambridge.
git://git.exim.org / users / jgh / exim.git / blobdiff