| 1 |
The pcretest program |
PCRETEST(1) PCRETEST(1) |
|
-------------------- |
|
| 2 |
|
|
|
This program is intended for testing PCRE, but it can also be used for |
|
|
experimenting with regular expressions. |
|
| 3 |
|
|
|
If it 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. |
|
|
|
|
|
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. 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-alphameric delimiters other than |
|
|
backslash, for example |
|
|
|
|
|
/(a|bc)x+yz/ |
|
|
|
|
|
White space before the initial delimiter is ignored. A regular expression may |
|
|
be continued over several input lines, in which case the newline characters are |
|
|
included within it. See the test input files in the testdata directory for many |
|
|
examples. 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-alphameric, this does not affect its interpretation. |
|
|
If the terminating delimiter is immediately followed 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 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. |
|
|
|
|
|
The pattern may be followed by i, m, s, or x to set the PCRE_CASELESS, |
|
|
PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options, respectively. For |
|
|
example: |
|
|
|
|
|
/caseless/i |
|
|
|
|
|
These modifier letters have the same effect as they do in Perl. There are |
|
|
others which set PCRE options that do not correspond to anything in Perl: /A, |
|
|
/E, and /X set PCRE_ANCHORED, PCRE_DOLLAR_ENDONLY, and PCRE_EXTRA respectively. |
|
|
|
|
|
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). |
|
|
|
|
|
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. |
|
|
|
|
|
There are a number of other 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 subject contains multiple |
|
|
copies of the same substring. |
|
|
|
|
|
The /L modifier must be followed directly by the name of a locale, for example, |
|
|
|
|
|
/pattern/Lfr |
|
|
|
|
|
For this reason, it must be the last modifier letter. 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 appears. |
|
|
|
|
|
The /I modifier requests that pcretest output information about the compiled |
|
|
expression (whether it is anchored, has a fixed first character, and so on). It |
|
|
does this by calling pcre_fullinfo() after compiling an expression, and |
|
|
outputting the information it gets back. If the pattern is studied, the results |
|
|
of that are also output. |
|
|
|
|
|
The /D modifier is a PCRE debugging feature, which also assumes /I. It causes |
|
|
the internal form of compiled regular expressions to be output after |
|
|
compilation. |
|
|
|
|
|
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. |
|
|
|
|
|
Finally, 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. |
|
|
|
|
|
Before each data line is passed to pcre_exec(), leading and trailing whitespace |
|
|
is removed, and it is then scanned for \ escapes. The following are recognized: |
|
|
|
|
|
\a alarm (= BEL) |
|
|
\b backspace |
|
|
\e escape |
|
|
\f formfeed |
|
|
\n newline |
|
|
\r carriage return |
|
|
\t tab |
|
|
\v vertical tab |
|
|
\nnn octal character (up to 3 octal digits) |
|
|
\xhh hexadecimal character (up to 2 hex digits) |
|
|
|
|
|
\A pass the PCRE_ANCHORED option to pcre_exec() |
|
|
\B pass the PCRE_NOTBOL option to pcre_exec() |
|
|
\Cdd call pcre_copy_substring() for substring dd after a successful match |
|
|
(any decimal number less than 32) |
|
|
\Gdd call pcre_get_substring() for substring dd after a successful match |
|
|
(any decimal number less than 32) |
|
|
\L call pcre_get_substringlist() after a successful match |
|
|
\N pass the PCRE_NOTEMPTY option to pcre_exec() |
|
|
\Odd set the size of the output vector passed to pcre_exec() to dd |
|
|
(any number of decimal digits) |
|
|
\Z pass the PCRE_NOTEOL option to pcre_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 terminates the data input. |
|
|
|
|
|
If /P was present on the regex, causing the POSIX wrapper API to be used, only |
|
|
\B, and \Z have any effect, causing REG_NOTBOL and REG_NOTEOL to be passed to |
|
|
regexec() respectively. |
|
|
|
|
|
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. Here is an example of an interactive pcretest run. |
|
|
|
|
|
$ pcretest |
|
|
PCRE version 2.06 08-Jun-1999 |
|
|
|
|
|
re> /^abc(\d+)/ |
|
|
data> abc123 |
|
|
0: abc123 |
|
|
1: 123 |
|
|
data> xyz |
|
|
No match |
|
|
|
|
|
If the strings contain any non-printing characters, they are output as \0x |
|
|
escapes. If the pattern has the /+ modifier, then 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. |
|
|
|
|
|
If any of \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 addition 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. |
|
|
|
|
|
Note that while 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. |
|
|
|
|
|
If the -p option is given to pcretest, it is equivalent to adding /P to each |
|
|
regular expression: the POSIX wrapper API is used to call PCRE. None of the |
|
|
following flags has any effect in this case. |
|
|
|
|
|
If the option -d is given to pcretest, it is equivalent to adding /D to each |
|
|
regular expression: the internal form is output after compilation. |
|
|
|
|
|
If the option -i is given to pcretest, it is equivalent to adding /I to each |
|
|
regular expression: information about the compiled pattern is given after |
|
|
compilation. |
|
|
|
|
|
If the option -m is given to pcretest, it outputs the size of each compiled |
|
|
pattern after it has been compiled. It is equivalent to adding /M to each |
|
|
regular expression. For compatibility with earlier versions of pcretest, -s is |
|
|
a synonym for -m. |
|
|
|
|
|
If the -t option is given, each compile, study, and match is run 20000 times |
|
|
while being timed, and the resulting time per compile or match is output in |
|
|
milliseconds. Do not set -t with -s, because you will then get the size output |
|
|
20000 times and the timing will be distorted. If you want to change the number |
|
|
of repetitions used for timing, edit the definition of LOOPREPEAT at the top of |
|
|
pcretest.c |
|
| 4 |
|
|
| 5 |
Philip Hazel <ph10@cam.ac.uk> |
NAME |
| 6 |
January 2000 |
pcretest - a program for testing Perl-compatible regular expressions. |
| 7 |
|
|
| 8 |
|
SYNOPSIS |
| 9 |
|
|
| 10 |
|
pcretest [-C] [-d] [-i] [-m] [-o osize] [-p] [-t] [source] |
| 11 |
|
[destination] |
| 12 |
|
|
| 13 |
|
pcretest was written as a test program for the PCRE regular expression |
| 14 |
|
library itself, but it can also be used for experimenting with regular |
| 15 |
|
expressions. This document describes the features of the test program; |
| 16 |
|
for details of the regular expressions themselves, see the pcrepattern |
| 17 |
|
documentation. For details of the PCRE library function calls and their |
| 18 |
|
options, see the pcreapi documentation. |
| 19 |
|
|
| 20 |
|
|
| 21 |
|
OPTIONS |
| 22 |
|
|
| 23 |
|
-C Output the version number of the PCRE library, and all avail- |
| 24 |
|
able information about the optional features that are |
| 25 |
|
included, and then exit. |
| 26 |
|
|
| 27 |
|
-d Behave as if each regex had the /D (debug) modifier; the |
| 28 |
|
internal form is output after compilation. |
| 29 |
|
|
| 30 |
|
-i Behave as if each regex had the /I modifier; information |
| 31 |
|
about the compiled pattern is given after compilation. |
| 32 |
|
|
| 33 |
|
-m Output the size of each compiled pattern after it has been |
| 34 |
|
compiled. This is equivalent to adding /M to each regular |
| 35 |
|
expression. For compatibility with earlier versions of |
| 36 |
|
pcretest, -s is a synonym for -m. |
| 37 |
|
|
| 38 |
|
-o osize Set the number of elements in the output vector that is used |
| 39 |
|
when calling pcre_exec() to be osize. The default value is |
| 40 |
|
45, which is enough for 14 capturing subexpressions. The vec- |
| 41 |
|
tor size can be changed for individual matching calls by |
| 42 |
|
including \O in the data line (see below). |
| 43 |
|
|
| 44 |
|
-p Behave as if each regex has /P modifier; the POSIX wrapper |
| 45 |
|
API is used to call PCRE. None of the other options has any |
| 46 |
|
effect when -p is set. |
| 47 |
|
|
| 48 |
|
-t Run each compile, study, and match many times with a timer, |
| 49 |
|
and output resulting time per compile or match (in millisec- |
| 50 |
|
onds). Do not set -m with -t, because you will then get the |
| 51 |
|
size output a zillion times, and the timing will be dis- |
| 52 |
|
torted. |
| 53 |
|
|
| 54 |
|
|
| 55 |
|
DESCRIPTION |
| 56 |
|
|
| 57 |
|
If pcretest is given two filename arguments, it reads from the first |
| 58 |
|
and writes to the second. If it is given only one filename argument, it |
| 59 |
|
reads from that file and writes to stdout. Otherwise, it reads from |
| 60 |
|
stdin and writes to stdout, and prompts for each line of input, using |
| 61 |
|
"re>" to prompt for regular expressions, and "data>" to prompt for data |
| 62 |
|
lines. |
| 63 |
|
|
| 64 |
|
The program handles any number of sets of input on a single input file. |
| 65 |
|
Each set starts with a regular expression, and continues with any num- |
| 66 |
|
ber of data lines to be matched against the pattern. |
| 67 |
|
|
| 68 |
|
Each data line is matched separately and independently. If you want to |
| 69 |
|
do multiple-line matches, you have to use the \n escape sequence in a |
| 70 |
|
single line of input to encode the newline characters. The maximum |
| 71 |
|
length of data line is 30,000 characters. |
| 72 |
|
|
| 73 |
|
An empty line signals the end of the data lines, at which point a new |
| 74 |
|
regular expression is read. The regular expressions are given enclosed |
| 75 |
|
in any non-alphanumeric delimiters other than backslash, for example |
| 76 |
|
|
| 77 |
|
/(a|bc)x+yz/ |
| 78 |
|
|
| 79 |
|
White space before the initial delimiter is ignored. A regular expres- |
| 80 |
|
sion may be continued over several input lines, in which case the new- |
| 81 |
|
line characters are included within it. It is possible to include the |
| 82 |
|
delimiter within the pattern by escaping it, for example |
| 83 |
|
|
| 84 |
|
/abc\/def/ |
| 85 |
|
|
| 86 |
|
If you do so, the escape and the delimiter form part of the pattern, |
| 87 |
|
but since delimiters are always non-alphanumeric, this does not affect |
| 88 |
|
its interpretation. If the terminating delimiter is immediately fol- |
| 89 |
|
lowed by a backslash, for example, |
| 90 |
|
|
| 91 |
|
/abc/\ |
| 92 |
|
|
| 93 |
|
then a backslash is added to the end of the pattern. This is done to |
| 94 |
|
provide a way of testing the error condition that arises if a pattern |
| 95 |
|
finishes with a backslash, because |
| 96 |
|
|
| 97 |
|
/abc\/ |
| 98 |
|
|
| 99 |
|
is interpreted as the first line of a pattern that starts with "abc/", |
| 100 |
|
causing pcretest to read the next line as a continuation of the regular |
| 101 |
|
expression. |
| 102 |
|
|
| 103 |
|
|
| 104 |
|
PATTERN MODIFIERS |
| 105 |
|
|
| 106 |
|
A pattern may be followed by any number of modifiers, which are mostly |
| 107 |
|
single characters. Following Perl usage, these are referred to below |
| 108 |
|
as, for example, "the /i modifier", even though the delimiter of the |
| 109 |
|
pattern need not always be a slash, and no slash is used when writing |
| 110 |
|
modifiers. Whitespace may appear between the final pattern delimiter |
| 111 |
|
and the first modifier, and between the modifiers themselves. |
| 112 |
|
|
| 113 |
|
The /i, /m, /s, and /x modifiers set the PCRE_CASELESS, PCRE_MULTILINE, |
| 114 |
|
PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when pcre_com- |
| 115 |
|
pile() is called. These four modifier letters have the same effect as |
| 116 |
|
they do in Perl. For example: |
| 117 |
|
|
| 118 |
|
/caseless/i |
| 119 |
|
|
| 120 |
|
The following table shows additional modifiers for setting PCRE options |
| 121 |
|
that do not correspond to anything in Perl: |
| 122 |
|
|
| 123 |
|
/A PCRE_ANCHORED |
| 124 |
|
/C PCRE_AUTO_CALLOUT |
| 125 |
|
/E PCRE_DOLLAR_ENDONLY |
| 126 |
|
/N PCRE_NO_AUTO_CAPTURE |
| 127 |
|
/U PCRE_UNGREEDY |
| 128 |
|
/X PCRE_EXTRA |
| 129 |
|
|
| 130 |
|
Searching for all possible matches within each subject string can be |
| 131 |
|
requested by the /g or /G modifier. After finding a match, PCRE is |
| 132 |
|
called again to search the remainder of the subject string. The differ- |
| 133 |
|
ence between /g and /G is that the former uses the startoffset argument |
| 134 |
|
to pcre_exec() to start searching at a new point within the entire |
| 135 |
|
string (which is in effect what Perl does), whereas the latter passes |
| 136 |
|
over a shortened substring. This makes a difference to the matching |
| 137 |
|
process if the pattern begins with a lookbehind assertion (including \b |
| 138 |
|
or \B). |
| 139 |
|
|
| 140 |
|
If any call to pcre_exec() in a /g or /G sequence matches an empty |
| 141 |
|
string, the next call is done with the PCRE_NOTEMPTY and PCRE_ANCHORED |
| 142 |
|
flags set in order to search for another, non-empty, match at the same |
| 143 |
|
point. If this second match fails, the start offset is advanced by |
| 144 |
|
one, and the normal match is retried. This imitates the way Perl han- |
| 145 |
|
dles such cases when using the /g modifier or the split() function. |
| 146 |
|
|
| 147 |
|
There are yet more modifiers for controlling the way pcretest operates. |
| 148 |
|
|
| 149 |
|
The /+ modifier requests that as well as outputting the substring that |
| 150 |
|
matched the entire pattern, pcretest should in addition output the |
| 151 |
|
remainder of the subject string. This is useful for tests where the |
| 152 |
|
subject contains multiple copies of the same substring. |
| 153 |
|
|
| 154 |
|
The /L modifier must be followed directly by the name of a locale, for |
| 155 |
|
example, |
| 156 |
|
|
| 157 |
|
/pattern/Lfr_FR |
| 158 |
|
|
| 159 |
|
For this reason, it must be the last modifier. The given locale is set, |
| 160 |
|
pcre_maketables() is called to build a set of character tables for the |
| 161 |
|
locale, and this is then passed to pcre_compile() when compiling the |
| 162 |
|
regular expression. Without an /L modifier, NULL is passed as the |
| 163 |
|
tables pointer; that is, /L applies only to the expression on which it |
| 164 |
|
appears. |
| 165 |
|
|
| 166 |
|
The /I modifier requests that pcretest output information about the |
| 167 |
|
compiled pattern (whether it is anchored, has a fixed first character, |
| 168 |
|
and so on). It does this by calling pcre_fullinfo() after compiling a |
| 169 |
|
pattern. If the pattern is studied, the results of that are also out- |
| 170 |
|
put. |
| 171 |
|
|
| 172 |
|
The /D modifier is a PCRE debugging feature, which also assumes /I. It |
| 173 |
|
causes the internal form of compiled regular expressions to be output |
| 174 |
|
after compilation. If the pattern was studied, the information returned |
| 175 |
|
is also output. |
| 176 |
|
|
| 177 |
|
The /F modifier causes pcretest to flip the byte order of the fields in |
| 178 |
|
the compiled pattern that contain 2-byte and 4-byte numbers. This |
| 179 |
|
facility is for testing the feature in PCRE that allows it to execute |
| 180 |
|
patterns that were compiled on a host with a different endianness. This |
| 181 |
|
feature is not available when the POSIX interface to PCRE is being |
| 182 |
|
used, that is, when the /P pattern modifier is specified. See also the |
| 183 |
|
section about saving and reloading compiled patterns below. |
| 184 |
|
|
| 185 |
|
The /S modifier causes pcre_study() to be called after the expression |
| 186 |
|
has been compiled, and the results used when the expression is matched. |
| 187 |
|
|
| 188 |
|
The /M modifier causes the size of memory block used to hold the com- |
| 189 |
|
piled pattern to be output. |
| 190 |
|
|
| 191 |
|
The /P modifier causes pcretest to call PCRE via the POSIX wrapper API |
| 192 |
|
rather than its native API. When this is done, all other modifiers |
| 193 |
|
except /i, /m, and /+ are ignored. REG_ICASE is set if /i is present, |
| 194 |
|
and REG_NEWLINE is set if /m is present. The wrapper functions force |
| 195 |
|
PCRE_DOLLAR_ENDONLY always, and PCRE_DOTALL unless REG_NEWLINE is set. |
| 196 |
|
|
| 197 |
|
The /8 modifier causes pcretest to call PCRE with the PCRE_UTF8 option |
| 198 |
|
set. This turns on support for UTF-8 character handling in PCRE, pro- |
| 199 |
|
vided that it was compiled with this support enabled. This modifier |
| 200 |
|
also causes any non-printing characters in output strings to be printed |
| 201 |
|
using the \x{hh...} notation if they are valid UTF-8 sequences. |
| 202 |
|
|
| 203 |
|
If the /? modifier is used with /8, it causes pcretest to call |
| 204 |
|
pcre_compile() with the PCRE_NO_UTF8_CHECK option, to suppress the |
| 205 |
|
checking of the string for UTF-8 validity. |
| 206 |
|
|
| 207 |
|
|
| 208 |
|
DATA LINES |
| 209 |
|
|
| 210 |
|
Before each data line is passed to pcre_exec(), leading and trailing |
| 211 |
|
whitespace is removed, and it is then scanned for \ escapes. Some of |
| 212 |
|
these are pretty esoteric features, intended for checking out some of |
| 213 |
|
the more complicated features of PCRE. If you are just testing "ordi- |
| 214 |
|
nary" regular expressions, you probably don't need any of these. The |
| 215 |
|
following escapes are recognized: |
| 216 |
|
|
| 217 |
|
\a alarm (= BEL) |
| 218 |
|
\b backspace |
| 219 |
|
\e escape |
| 220 |
|
\f formfeed |
| 221 |
|
\n newline |
| 222 |
|
\r carriage return |
| 223 |
|
\t tab |
| 224 |
|
\v vertical tab |
| 225 |
|
\nnn octal character (up to 3 octal digits) |
| 226 |
|
\xhh hexadecimal character (up to 2 hex digits) |
| 227 |
|
\x{hh...} hexadecimal character, any number of digits |
| 228 |
|
in UTF-8 mode |
| 229 |
|
\A pass the PCRE_ANCHORED option to pcre_exec() |
| 230 |
|
\B pass the PCRE_NOTBOL option to pcre_exec() |
| 231 |
|
\Cdd call pcre_copy_substring() for substring dd |
| 232 |
|
after a successful match (number less than 32) |
| 233 |
|
\Cname call pcre_copy_named_substring() for substring |
| 234 |
|
"name" after a successful match (name termin- |
| 235 |
|
ated by next non alphanumeric character) |
| 236 |
|
\C+ show the current captured substrings at callout |
| 237 |
|
time |
| 238 |
|
\C- do not supply a callout function |
| 239 |
|
\C!n return 1 instead of 0 when callout number n is |
| 240 |
|
reached |
| 241 |
|
\C!n!m return 1 instead of 0 when callout number n is |
| 242 |
|
reached for the nth time |
| 243 |
|
\C*n pass the number n (may be negative) as callout |
| 244 |
|
data; this is used as the callout return value |
| 245 |
|
\Gdd call pcre_get_substring() for substring dd |
| 246 |
|
after a successful match (number less than 32) |
| 247 |
|
\Gname call pcre_get_named_substring() for substring |
| 248 |
|
"name" after a successful match (name termin- |
| 249 |
|
ated by next non-alphanumeric character) |
| 250 |
|
\L call pcre_get_substringlist() after a |
| 251 |
|
successful match |
| 252 |
|
\M discover the minimum MATCH_LIMIT setting |
| 253 |
|
\N pass the PCRE_NOTEMPTY option to pcre_exec() |
| 254 |
|
\Odd set the size of the output vector passed to |
| 255 |
|
pcre_exec() to dd (any number of digits) |
| 256 |
|
\P pass the PCRE_PARTIAL option to pcre_exec() |
| 257 |
|
\S output details of memory get/free calls during matching |
| 258 |
|
\Z pass the PCRE_NOTEOL option to pcre_exec() |
| 259 |
|
\? pass the PCRE_NO_UTF8_CHECK option to |
| 260 |
|
pcre_exec() |
| 261 |
|
\>dd start the match at offset dd (any number of digits); |
| 262 |
|
this sets the startoffset argument for pcre_exec() |
| 263 |
|
|
| 264 |
|
A backslash followed by anything else just escapes the anything else. |
| 265 |
|
If the very last character is a backslash, it is ignored. This gives a |
| 266 |
|
way of passing an empty line as data, since a real empty line termi- |
| 267 |
|
nates the data input. |
| 268 |
|
|
| 269 |
|
If \M is present, pcretest calls pcre_exec() several times, with dif- |
| 270 |
|
ferent values in the match_limit field of the pcre_extra data struc- |
| 271 |
|
ture, until it finds the minimum number that is needed for pcre_exec() |
| 272 |
|
to complete. This number is a measure of the amount of recursion and |
| 273 |
|
backtracking that takes place, and checking it out can be instructive. |
| 274 |
|
For most simple matches, the number is quite small, but for patterns |
| 275 |
|
with very large numbers of matching possibilities, it can become large |
| 276 |
|
very quickly with increasing length of subject string. |
| 277 |
|
|
| 278 |
|
When \O is used, the value specified may be higher or lower than the |
| 279 |
|
size set by the -O command line option (or defaulted to 45); \O applies |
| 280 |
|
only to the call of pcre_exec() for the line in which it appears. |
| 281 |
|
|
| 282 |
|
If the /P modifier was present on the pattern, causing the POSIX wrap- |
| 283 |
|
per API to be used, only \B and \Z have any effect, causing REG_NOTBOL |
| 284 |
|
and REG_NOTEOL to be passed to regexec() respectively. |
| 285 |
|
|
| 286 |
|
The use of \x{hh...} to represent UTF-8 characters is not dependent on |
| 287 |
|
the use of the /8 modifier on the pattern. It is recognized always. |
| 288 |
|
There may be any number of hexadecimal digits inside the braces. The |
| 289 |
|
result is from one to six bytes, encoded according to the UTF-8 rules. |
| 290 |
|
|
| 291 |
|
|
| 292 |
|
OUTPUT FROM PCRETEST |
| 293 |
|
|
| 294 |
|
When a match succeeds, pcretest outputs the list of captured substrings |
| 295 |
|
that pcre_exec() returns, starting with number 0 for the string that |
| 296 |
|
matched the whole pattern. Otherwise, it outputs "No match" or "Partial |
| 297 |
|
match" when pcre_exec() returns PCRE_ERROR_NOMATCH or PCRE_ERROR_PAR- |
| 298 |
|
TIAL, respectively, and otherwise the PCRE negative error number. Here |
| 299 |
|
is an example of an interactive pcretest run. |
| 300 |
|
|
| 301 |
|
$ pcretest |
| 302 |
|
PCRE version 5.00 07-Sep-2004 |
| 303 |
|
|
| 304 |
|
re> /^abc(\d+)/ |
| 305 |
|
data> abc123 |
| 306 |
|
0: abc123 |
| 307 |
|
1: 123 |
| 308 |
|
data> xyz |
| 309 |
|
No match |
| 310 |
|
|
| 311 |
|
If the strings contain any non-printing characters, they are output as |
| 312 |
|
\0x escapes, or as \x{...} escapes if the /8 modifier was present on |
| 313 |
|
the pattern. If the pattern has the /+ modifier, the output for sub- |
| 314 |
|
string 0 is followed by the the rest of the subject string, identified |
| 315 |
|
by "0+" like this: |
| 316 |
|
|
| 317 |
|
re> /cat/+ |
| 318 |
|
data> cataract |
| 319 |
|
0: cat |
| 320 |
|
0+ aract |
| 321 |
|
|
| 322 |
|
If the pattern has the /g or /G modifier, the results of successive |
| 323 |
|
matching attempts are output in sequence, like this: |
| 324 |
|
|
| 325 |
|
re> /\Bi(\w\w)/g |
| 326 |
|
data> Mississippi |
| 327 |
|
0: iss |
| 328 |
|
1: ss |
| 329 |
|
0: iss |
| 330 |
|
1: ss |
| 331 |
|
0: ipp |
| 332 |
|
1: pp |
| 333 |
|
|
| 334 |
|
"No match" is output only if the first match attempt fails. |
| 335 |
|
|
| 336 |
|
If any of the sequences \C, \G, or \L are present in a data line that |
| 337 |
|
is successfully matched, the substrings extracted by the convenience |
| 338 |
|
functions are output with C, G, or L after the string number instead of |
| 339 |
|
a colon. This is in addition to the normal full list. The string length |
| 340 |
|
(that is, the return from the extraction function) is given in paren- |
| 341 |
|
theses after each string for \C and \G. |
| 342 |
|
|
| 343 |
|
Note that while patterns can be continued over several lines (a plain |
| 344 |
|
">" prompt is used for continuations), data lines may not. However new- |
| 345 |
|
lines can be included in data by means of the \n escape. |
| 346 |
|
|
| 347 |
|
|
| 348 |
|
CALLOUTS |
| 349 |
|
|
| 350 |
|
If the pattern contains any callout requests, pcretest's callout func- |
| 351 |
|
tion is called during matching. By default, it displays the callout |
| 352 |
|
number, the start and current positions in the text at the callout |
| 353 |
|
time, and the next pattern item to be tested. For example, the output |
| 354 |
|
|
| 355 |
|
--->pqrabcdef |
| 356 |
|
0 ^ ^ \d |
| 357 |
|
|
| 358 |
|
indicates that callout number 0 occurred for a match attempt starting |
| 359 |
|
at the fourth character of the subject string, when the pointer was at |
| 360 |
|
the seventh character of the data, and when the next pattern item was |
| 361 |
|
\d. Just one circumflex is output if the start and current positions |
| 362 |
|
are the same. |
| 363 |
|
|
| 364 |
|
Callouts numbered 255 are assumed to be automatic callouts, inserted as |
| 365 |
|
a result of the /C pattern modifier. In this case, instead of showing |
| 366 |
|
the callout number, the offset in the pattern, preceded by a plus, is |
| 367 |
|
output. For example: |
| 368 |
|
|
| 369 |
|
re> /\d?[A-E]\*/C |
| 370 |
|
data> E* |
| 371 |
|
--->E* |
| 372 |
|
+0 ^ \d? |
| 373 |
|
+3 ^ [A-E] |
| 374 |
|
+8 ^^ \* |
| 375 |
|
+10 ^ ^ |
| 376 |
|
0: E* |
| 377 |
|
|
| 378 |
|
The callout function in pcretest returns zero (carry on matching) by |
| 379 |
|
default, but you can use an \C item in a data line (as described above) |
| 380 |
|
to change this. |
| 381 |
|
|
| 382 |
|
Inserting callouts can be helpful when using pcretest to check compli- |
| 383 |
|
cated regular expressions. For further information about callouts, see |
| 384 |
|
the pcrecallout documentation. |
| 385 |
|
|
| 386 |
|
|
| 387 |
|
SAVING AND RELOADING COMPILED PATTERNS |
| 388 |
|
|
| 389 |
|
The facilities described in this section are not available when the |
| 390 |
|
POSIX inteface to PCRE is being used, that is, when the /P pattern mod- |
| 391 |
|
ifier is specified. |
| 392 |
|
|
| 393 |
|
When the POSIX interface is not in use, you can cause pcretest to write |
| 394 |
|
a compiled pattern to a file, by following the modifiers with > and a |
| 395 |
|
file name. For example: |
| 396 |
|
|
| 397 |
|
/pattern/im >/some/file |
| 398 |
|
|
| 399 |
|
See the pcreprecompile documentation for a discussion about saving and |
| 400 |
|
re-using compiled patterns. |
| 401 |
|
|
| 402 |
|
The data that is written is binary. The first eight bytes are the |
| 403 |
|
length of the compiled pattern data followed by the length of the |
| 404 |
|
optional study data, each written as four bytes in big-endian order |
| 405 |
|
(most significant byte first). If there is no study data (either the |
| 406 |
|
pattern was not studied, or studying did not return any data), the sec- |
| 407 |
|
ond length is zero. The lengths are followed by an exact copy of the |
| 408 |
|
compiled pattern. If there is additional study data, this follows imme- |
| 409 |
|
diately after the compiled pattern. After writing the file, pcretest |
| 410 |
|
expects to read a new pattern. |
| 411 |
|
|
| 412 |
|
A saved pattern can be reloaded into pcretest by specifing < and a file |
| 413 |
|
name instead of a pattern. The name of the file must not contain a < |
| 414 |
|
character, as otherwise pcretest will interpret the line as a pattern |
| 415 |
|
delimited by < characters. For example: |
| 416 |
|
|
| 417 |
|
re> </some/file |
| 418 |
|
Compiled regex loaded from /some/file |
| 419 |
|
No study data |
| 420 |
|
|
| 421 |
|
When the pattern has been loaded, pcretest proceeds to read data lines |
| 422 |
|
in the usual way. |
| 423 |
|
|
| 424 |
|
You can copy a file written by pcretest to a different host and reload |
| 425 |
|
it there, even if the new host has opposite endianness to the one on |
| 426 |
|
which the pattern was compiled. For example, you can compile on an i86 |
| 427 |
|
machine and run on a SPARC machine. |
| 428 |
|
|
| 429 |
|
File names for saving and reloading can be absolute or relative, but |
| 430 |
|
note that the shell facility of expanding a file name that starts with |
| 431 |
|
a tilde (~) is not available. |
| 432 |
|
|
| 433 |
|
The ability to save and reload files in pcretest is intended for test- |
| 434 |
|
ing and experimentation. It is not intended for production use because |
| 435 |
|
only a single pattern can be written to a file. Furthermore, there is |
| 436 |
|
no facility for supplying custom character tables for use with a |
| 437 |
|
reloaded pattern. If the original pattern was compiled with custom |
| 438 |
|
tables, an attempt to match a subject string using a reloaded pattern |
| 439 |
|
is likely to cause pcretest to crash. Finally, if you attempt to load |
| 440 |
|
a file that is not in the correct format, the result is undefined. |
| 441 |
|
|
| 442 |
|
|
| 443 |
|
AUTHOR |
| 444 |
|
|
| 445 |
|
Philip Hazel <ph10@cam.ac.uk> |
| 446 |
|
University Computing Service, |
| 447 |
|
Cambridge CB2 3QG, England. |
| 448 |
|
|
| 449 |
|
Last updated: 10 September 2004 |
| 450 |
|
Copyright (c) 1997-2004 University of Cambridge. |
Parent Directory
| 
Revision Log
| 
Patch