User Commands PCRETEST(1)
NAME
pcretest - a program for testing Perl-compatible regular
expressions.SYNOPSIS
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 expressions. This document describes the features of the test program; for details of the regular expressions themselves, see the pcrepattern documentation. For details of the PCRE library function calls and their options, see the pcreapi documentation. OPTIONS-b Behave as if each regex has the /B (show bytecode)
modifier; the internal form is output after compi-
lation.-C Output the version number of the PCRE library, and
all available information about the optional features that are included, and then exit.-d Behave as if each regex has the /D (debug) modif-
ier; the internal form and information about thecompiled 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 matchingfunction, 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 regex has the /I modifier;
information about the compiled pattern is given after compilation.-m Output the size of each compiled pattern after it
has been compiled. This is equivalent to adding /M to each regular expression. For compatibility with
earlier versions of pcretest, -s is a synonym for
-m.
-o osize Set the number of elements in the output vector
that is used when calling pcre_exec() or
SunOS 5.10 Last change: 1 User Commands PCRETEST(1)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 regex has the /P modifier; the
POSIX wrapper API is used to call PCRE. None ofthe 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 ormatch (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 usedfor 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 readusing 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. SunOS 5.10 Last change: 2 User Commands PCRETEST(1) Each data line is matched separately and independently. Ifyou 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 whichpoint 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 regu-
lar 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 thepattern, but since delimiters are always non-alphanumeric,
this does not affect its interpretation. If the terminatingdelimiter 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 startswith "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 bea slash, and no slash is used when writing modifiers. Whi-
tespace may appear between the final pattern delimiter and the first modifier, and between the modifiers themselves. SunOS 5.10 Last change: 3 User Commands PCRETEST(1)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
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
/J PCRE_DUPNAMES
/N PCRE_NO_AUTO_CAPTURE
/U PCRE_UNGREEDY
/X PCRE_EXTRA
/
PCRE_JAVASCRIPT_COMPAT /
PCRE_NEWLINE_CR /
PCRE_NEWLINE_LF /
PCRE_NEWLINE_CRLF /
PCRE_NEWLINE_ANYCRLF /
PCRE_NEWLINE_ANY /
PCRE_BSR_ANYCRLF /
Those specifying line ending sequences are literal stringsPCRE_BSR_UNICODE as shown, but the letters can be in either case. This exam-
ple sets multiline matching with CRLF as the line ending sequence: /^abc/mDetails of the meanings of these 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 remainder 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). SunOS 5.10 Last change: 4 User Commands PCRETEST(1)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 handles such cases when using the /g modifier or the split() function. Other modifiers There are yet more modifiers for controlling the waypcretest 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.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 lengthand 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 /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 givenlocale is set, pcre_maketables() is called to build a set of
character tables for the locale, and this is then passed topcre_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 callingpcre_fullinfo() after compiling a pattern. If the pattern is
studied, the results of that are also output.The /D modifier is a PCRE debugging feature, and is
equivalent to /BI, that is, both the /B and the /I modif-
iers.The /F modifier causes pcretest to flip the byte order of
the fields in the compiled pattern that contain 2-byte and
SunOS 5.10 Last change: 5 User Commands PCRETEST(1)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 /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 compiled 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 forcePCRE_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 char-
acter handling in PCRE, provided that it was compiled withthis support enabled. This modifier also causes any non-
printing characters in output strings to be printed usingthe \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 checking of the string for UTF-8 validity.
DATA LINESBefore 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 "ordinary" regularexpressions, 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 formfeed (\x0c) \n newline (\x0a)\qdd set the PCRE_MATCH_LIMIT limit to dd
(any number of digits) \r carriage return (\x0d) SunOS 5.10 Last change: 6 User Commands PCRETEST(1) \t tab (\x09) \v vertical tab (\x0b) \nnn octal character (up to 3 octal digits) \xhh hexadecimal character (up to 2 hex digits) \x{hh...} hexadecimal character, any number of digitsin 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)
\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()
\Odd set the size of the output vector passed topcre_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()
SunOS 5.10 Last change: 7 User Commands PCRETEST(1)\? pass the PCRE_NO_UTF8_CHECK option to
pcre_exec() or pcre_dfa_exec()
\>dd start the match at offset dd (any number of digits); this sets the startoffset argument forpcre_exec()
or pcre_dfa_exec()
\
pass the PCRE_NEWLINE_CR option to pcre_exec() or pcre_dfa_exec()
\
pass the PCRE_NEWLINE_LF option to pcre_exec() or pcre_dfa_exec()
\
pass the PCRE_NEWLINE_CRLF option to pcre_exec()
or pcre_dfa_exec()
\
pass the PCRE_NEWLINE_ANYCRLF option to pcre_exec()
or pcre_dfa_exec()
\
pass the PCRE_NEWLINE_ANY option to pcre_exec() or pcre_dfa_exec()
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.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 parameterthat allow pcre_exec() to complete. The match_limit number
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 lowerthan 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 and \Z, causingREG_NOTBOL and REG_NOTEOL, respectively, to be passed to
SunOS 5.10 Last change: 8 User Commands PCRETEST(1) 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 sixbytes, 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, orindeed valid UTF-8 characters according to the later rules
in RFC 3629. THE ALTERNATIVE MATCHING FUNCTIONBy 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 thecommand line contains the -dfa option, the alternative
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 matchingfunction, 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, itoutputs "No match" or "Partial match" when pcre_exec()
returns PCRE_ERROR_NOMATCH or PCRE_ERROR_PARTIAL, respec-
tively, and otherwise the PCRE negative error number. Hereis an example of an interactive pcretest run.
$ pcretest
PCRE version 7.0 30-Nov-2006
re> /^abc(\d+)/ data> abc123 0: abc123 1: 123 data> xyz No match SunOS 5.10 Last change: 9 User Commands PCRETEST(1) Note that unset capturing substrings that are not followedby 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 "", as for the second data line. re> /(a)|(b)/ data> a 0: a 1: a data> b 0: b 1: 2: b If the strings contain any non-printing characters, they are
output as \0x escapes, or as \x{...} escapes if the /8 modifier was present on the pattern. See below for thedefinition 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+ aractIf 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. 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 parentheses after each string for \C and \G. SunOS 5.10 Last change: 10 User Commands PCRETEST(1) 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
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). If /g is present on the pattern, the search for furthermatches 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: tanSince 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 thePCRE_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 SunOS 5.10 Last change: 11 User Commands PCRETEST(1) Partial match: 23ja data> n05\R\D 0: n05 For further information about partial matching, see the pcrepartial documentation. CALLOUTSIf 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*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 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
SunOS 5.10 Last change: 12 User Commands PCRETEST(1) escapes.When pcretest is outputting text that is a matched part of a
subject string, it behaves in the same way, unless a dif-
ferent locale has been set for the pattern (using the /L
modifier). In this case, the isprint() function to distin-
guish printing and non-printing characters.
SAVING AND RELOADING COMPILED PATTERNS The facilities described in this section are not available when the POSIX inteface to PCRE is being used, that is, whenthe /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 aboutsaving 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 fourbytes 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 iszero. The lengths are followed by an exact copy of the com-
piled pattern. If there is additional study data, this fol-
lows immediately after the compiled pattern. After writingthe 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 filemust not contain a < character, as otherwise pcretest will
interpret the line as a pattern delimited by < characters. For example: re>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 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. SunOS 5.10 Last change: 13 User Commands PCRETEST(1)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 toa 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 likelyto cause pcretest to crash. Finally, if you attempt to load
a file that is not in the correct format, the result is undefined.SEE ALSO
pcre(3), pcreapi(3), pcrecallout(3), pcrematching(3), pcrepartial(d), pcrepattern(3), pcreprecompile(3). AUTHOR Philip Hazel University Computing Service Cambridge CB2 3QH, England. REVISION Last updated: 12 April 2008Copyright (c) 1997-2008 University of Cambridge.
ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:_______________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE|
|____________________|__________________|_
| Availability | library/pcre ||____________________|__________________|_
| Interface Stability| Uncommitted ||____________________|_________________|
NOTES Source for PCRE is available on http://opensolaris.org. SunOS 5.10 Last change: 14