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1 | This file contains the PCRE man page that described the pcretest program. Note |
2 | that not all of the features of PCRE are available in the limited version that | |
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3 | is built with Exim. |
4 | ------------------------------------------------------------------------------- | |
5 | ||
6 | PCRETEST(1) PCRETEST(1) | |
7 | ||
8 | ||
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9 | NAME |
10 | pcretest - a program for testing Perl-compatible regular expressions. | |
11 | ||
92e772ff | 12 | |
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13 | SYNOPSIS |
14 | ||
aa41d2de | 15 | pcretest [options] [source] [destination] |
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16 | |
17 | pcretest was written as a test program for the PCRE regular expression | |
18 | library itself, but it can also be used for experimenting with regular | |
19 | expressions. This document describes the features of the test program; | |
20 | for details of the regular expressions themselves, see the pcrepattern | |
21 | documentation. For details of the PCRE library function calls and their | |
22 | options, see the pcreapi documentation. | |
23 | ||
24 | ||
25 | OPTIONS | |
26 | ||
27 | -C Output the version number of the PCRE library, and all avail- | |
28 | able information about the optional features that are | |
29 | included, and then exit. | |
30 | ||
8ac170f3 | 31 | -d Behave as if each regex has the /D (debug) modifier; the |
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32 | internal form is output after compilation. |
33 | ||
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34 | -dfa Behave as if each data line contains the \D escape sequence; |
35 | this causes the alternative matching function, | |
36 | pcre_dfa_exec(), to be used instead of the standard | |
37 | pcre_exec() function (more detail is given below). | |
38 | ||
39 | -i Behave as if each regex has the /I modifier; information | |
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40 | about the compiled pattern is given after compilation. |
41 | ||
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42 | -m Output the size of each compiled pattern after it has been |
43 | compiled. This is equivalent to adding /M to each regular | |
44 | expression. For compatibility with earlier versions of | |
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45 | pcretest, -s is a synonym for -m. |
46 | ||
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47 | -o osize Set the number of elements in the output vector that is used |
48 | when calling pcre_exec() to be osize. The default value is | |
495ae4b0 | 49 | 45, which is enough for 14 capturing subexpressions. The vec- |
8ac170f3 | 50 | tor size can be changed for individual matching calls by |
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51 | including \O in the data line (see below). |
52 | ||
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53 | -p Behave as if each regex has the /P modifier; the POSIX wrap- |
54 | per API is used to call PCRE. None of the other options has | |
55 | any effect when -p is set. | |
495ae4b0 | 56 | |
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57 | -q Do not output the version number of pcretest at the start of |
58 | execution. | |
59 | ||
60 | -S size On Unix-like systems, set the size of the runtime stack to | |
61 | size megabytes. | |
62 | ||
8ac170f3 PH |
63 | -t Run each compile, study, and match many times with a timer, |
64 | and output resulting time per compile or match (in millisec- | |
65 | onds). Do not set -m with -t, because you will then get the | |
66 | size output a zillion times, and the timing will be dis- | |
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67 | torted. |
68 | ||
69 | ||
70 | DESCRIPTION | |
71 | ||
8ac170f3 | 72 | If pcretest is given two filename arguments, it reads from the first |
495ae4b0 | 73 | and writes to the second. If it is given only one filename argument, it |
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74 | reads from that file and writes to stdout. Otherwise, it reads from |
75 | stdin and writes to stdout, and prompts for each line of input, using | |
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76 | "re>" to prompt for regular expressions, and "data>" to prompt for data |
77 | lines. | |
78 | ||
79 | The program handles any number of sets of input on a single input file. | |
8ac170f3 | 80 | Each set starts with a regular expression, and continues with any num- |
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81 | ber of data lines to be matched against the pattern. |
82 | ||
8ac170f3 | 83 | Each data line is matched separately and independently. If you want to |
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84 | do multi-line matches, you have to use the \n escape sequence (or \r or |
85 | \r\n, depending on the newline setting) in a single line of input to | |
86 | encode the newline characters. There is no limit on the length of data | |
87 | lines; the input buffer is automatically extended if it is too small. | |
495ae4b0 | 88 | |
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89 | An empty line signals the end of the data lines, at which point a new |
90 | regular expression is read. The regular expressions are given enclosed | |
91 | in any non-alphanumeric delimiters other than backslash, for example: | |
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92 | |
93 | /(a|bc)x+yz/ | |
94 | ||
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95 | White space before the initial delimiter is ignored. A regular expres- |
96 | sion may be continued over several input lines, in which case the new- | |
97 | line characters are included within it. It is possible to include the | |
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98 | delimiter within the pattern by escaping it, for example |
99 | ||
100 | /abc\/def/ | |
101 | ||
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102 | If you do so, the escape and the delimiter form part of the pattern, |
103 | but since delimiters are always non-alphanumeric, this does not affect | |
104 | its interpretation. If the terminating delimiter is immediately fol- | |
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105 | lowed by a backslash, for example, |
106 | ||
107 | /abc/\ | |
108 | ||
aa41d2de PH |
109 | then a backslash is added to the end of the pattern. This is done to |
110 | provide a way of testing the error condition that arises if a pattern | |
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111 | finishes with a backslash, because |
112 | ||
113 | /abc\/ | |
114 | ||
aa41d2de | 115 | is interpreted as the first line of a pattern that starts with "abc/", |
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116 | causing pcretest to read the next line as a continuation of the regular |
117 | expression. | |
118 | ||
119 | ||
120 | PATTERN MODIFIERS | |
121 | ||
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122 | A pattern may be followed by any number of modifiers, which are mostly |
123 | single characters. Following Perl usage, these are referred to below | |
124 | as, for example, "the /i modifier", even though the delimiter of the | |
125 | pattern need not always be a slash, and no slash is used when writing | |
126 | modifiers. Whitespace may appear between the final pattern delimiter | |
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127 | and the first modifier, and between the modifiers themselves. |
128 | ||
129 | The /i, /m, /s, and /x modifiers set the PCRE_CASELESS, PCRE_MULTILINE, | |
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130 | PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when pcre_com- |
131 | pile() is called. These four modifier letters have the same effect as | |
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132 | they do in Perl. For example: |
133 | ||
134 | /caseless/i | |
135 | ||
136 | The following table shows additional modifiers for setting PCRE options | |
137 | that do not correspond to anything in Perl: | |
138 | ||
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139 | /A PCRE_ANCHORED |
140 | /C PCRE_AUTO_CALLOUT | |
141 | /E PCRE_DOLLAR_ENDONLY | |
142 | /f PCRE_FIRSTLINE | |
143 | /J PCRE_DUPNAMES | |
144 | /N PCRE_NO_AUTO_CAPTURE | |
145 | /U PCRE_UNGREEDY | |
146 | /X PCRE_EXTRA | |
147 | /<cr> PCRE_NEWLINE_CR | |
148 | /<lf> PCRE_NEWLINE_LF | |
149 | /<crlf> PCRE_NEWLINE_CRLF | |
150 | ||
151 | Those specifying line endings are literal strings as shown. Details of | |
152 | the meanings of these PCRE options are given in the pcreapi documenta- | |
153 | tion. | |
154 | ||
155 | Finding all matches in a string | |
156 | ||
157 | Searching for all possible matches within each subject string can be | |
158 | requested by the /g or /G modifier. After finding a match, PCRE is | |
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159 | called again to search the remainder of the subject string. The differ- |
160 | ence between /g and /G is that the former uses the startoffset argument | |
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161 | to pcre_exec() to start searching at a new point within the entire |
162 | string (which is in effect what Perl does), whereas the latter passes | |
163 | over a shortened substring. This makes a difference to the matching | |
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164 | process if the pattern begins with a lookbehind assertion (including \b |
165 | or \B). | |
166 | ||
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167 | If any call to pcre_exec() in a /g or /G sequence matches an empty |
168 | string, the next call is done with the PCRE_NOTEMPTY and PCRE_ANCHORED | |
169 | flags set in order to search for another, non-empty, match at the same | |
170 | point. If this second match fails, the start offset is advanced by | |
171 | one, and the normal match is retried. This imitates the way Perl han- | |
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172 | dles such cases when using the /g modifier or the split() function. |
173 | ||
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174 | Other modifiers |
175 | ||
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176 | There are yet more modifiers for controlling the way pcretest operates. |
177 | ||
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178 | The /+ modifier requests that as well as outputting the substring that |
179 | matched the entire pattern, pcretest should in addition output the | |
180 | remainder of the subject string. This is useful for tests where the | |
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181 | subject contains multiple copies of the same substring. |
182 | ||
aa41d2de | 183 | The /L modifier must be followed directly by the name of a locale, for |
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184 | example, |
185 | ||
186 | /pattern/Lfr_FR | |
187 | ||
188 | For this reason, it must be the last modifier. The given locale is set, | |
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189 | pcre_maketables() is called to build a set of character tables for the |
190 | locale, and this is then passed to pcre_compile() when compiling the | |
191 | regular expression. Without an /L modifier, NULL is passed as the | |
192 | tables pointer; that is, /L applies only to the expression on which it | |
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193 | appears. |
194 | ||
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195 | The /I modifier requests that pcretest output information about the |
196 | compiled pattern (whether it is anchored, has a fixed first character, | |
197 | and so on). It does this by calling pcre_fullinfo() after compiling a | |
198 | pattern. If the pattern is studied, the results of that are also out- | |
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199 | put. |
200 | ||
201 | The /D modifier is a PCRE debugging feature, which also assumes /I. It | |
aa41d2de | 202 | causes the internal form of compiled regular expressions to be output |
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203 | after compilation. If the pattern was studied, the information returned |
204 | is also output. | |
205 | ||
206 | The /F modifier causes pcretest to flip the byte order of the fields in | |
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207 | the compiled pattern that contain 2-byte and 4-byte numbers. This |
208 | facility is for testing the feature in PCRE that allows it to execute | |
495ae4b0 | 209 | patterns that were compiled on a host with a different endianness. This |
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210 | feature is not available when the POSIX interface to PCRE is being |
211 | used, that is, when the /P pattern modifier is specified. See also the | |
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212 | section about saving and reloading compiled patterns below. |
213 | ||
aa41d2de | 214 | The /S modifier causes pcre_study() to be called after the expression |
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215 | has been compiled, and the results used when the expression is matched. |
216 | ||
aa41d2de | 217 | The /M modifier causes the size of memory block used to hold the com- |
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218 | piled pattern to be output. |
219 | ||
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220 | The /P modifier causes pcretest to call PCRE via the POSIX wrapper API |
221 | rather than its native API. When this is done, all other modifiers | |
222 | except /i, /m, and /+ are ignored. REG_ICASE is set if /i is present, | |
223 | and REG_NEWLINE is set if /m is present. The wrapper functions force | |
224 | PCRE_DOLLAR_ENDONLY always, and PCRE_DOTALL unless REG_NEWLINE is set. | |
495ae4b0 | 225 | |
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226 | The /8 modifier causes pcretest to call PCRE with the PCRE_UTF8 option |
227 | set. This turns on support for UTF-8 character handling in PCRE, pro- | |
228 | vided that it was compiled with this support enabled. This modifier | |
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229 | also causes any non-printing characters in output strings to be printed |
230 | using the \x{hh...} notation if they are valid UTF-8 sequences. | |
231 | ||
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232 | If the /? modifier is used with /8, it causes pcretest to call |
233 | pcre_compile() with the PCRE_NO_UTF8_CHECK option, to suppress the | |
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234 | checking of the string for UTF-8 validity. |
235 | ||
236 | ||
237 | DATA LINES | |
238 | ||
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239 | Before each data line is passed to pcre_exec(), leading and trailing |
240 | whitespace is removed, and it is then scanned for \ escapes. Some of | |
241 | these are pretty esoteric features, intended for checking out some of | |
242 | the more complicated features of PCRE. If you are just testing "ordi- | |
243 | nary" regular expressions, you probably don't need any of these. The | |
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244 | following escapes are recognized: |
245 | ||
246 | \a alarm (= BEL) | |
247 | \b backspace | |
248 | \e escape | |
249 | \f formfeed | |
250 | \n newline | |
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251 | \qdd set the PCRE_MATCH_LIMIT limit to dd |
252 | (any number of digits) | |
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253 | \r carriage return |
254 | \t tab | |
255 | \v vertical tab | |
256 | \nnn octal character (up to 3 octal digits) | |
257 | \xhh hexadecimal character (up to 2 hex digits) | |
258 | \x{hh...} hexadecimal character, any number of digits | |
259 | in UTF-8 mode | |
260 | \A pass the PCRE_ANCHORED option to pcre_exec() | |
aa41d2de | 261 | or pcre_dfa_exec() |
495ae4b0 | 262 | \B pass the PCRE_NOTBOL option to pcre_exec() |
aa41d2de | 263 | or pcre_dfa_exec() |
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264 | \Cdd call pcre_copy_substring() for substring dd |
265 | after a successful match (number less than 32) | |
266 | \Cname call pcre_copy_named_substring() for substring | |
267 | "name" after a successful match (name termin- | |
268 | ated by next non alphanumeric character) | |
269 | \C+ show the current captured substrings at callout | |
270 | time | |
271 | \C- do not supply a callout function | |
272 | \C!n return 1 instead of 0 when callout number n is | |
273 | reached | |
274 | \C!n!m return 1 instead of 0 when callout number n is | |
275 | reached for the nth time | |
276 | \C*n pass the number n (may be negative) as callout | |
277 | data; this is used as the callout return value | |
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278 | \D use the pcre_dfa_exec() match function |
279 | \F only shortest match for pcre_dfa_exec() | |
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280 | \Gdd call pcre_get_substring() for substring dd |
281 | after a successful match (number less than 32) | |
282 | \Gname call pcre_get_named_substring() for substring | |
283 | "name" after a successful match (name termin- | |
284 | ated by next non-alphanumeric character) | |
285 | \L call pcre_get_substringlist() after a | |
286 | successful match | |
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287 | \M discover the minimum MATCH_LIMIT and |
288 | MATCH_LIMIT_RECURSION settings | |
495ae4b0 | 289 | \N pass the PCRE_NOTEMPTY option to pcre_exec() |
aa41d2de | 290 | or pcre_dfa_exec() |
495ae4b0 PH |
291 | \Odd set the size of the output vector passed to |
292 | pcre_exec() to dd (any number of digits) | |
293 | \P pass the PCRE_PARTIAL option to pcre_exec() | |
8ac170f3 | 294 | or pcre_dfa_exec() |
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295 | \Qdd set the PCRE_MATCH_LIMIT_RECURSION limit to dd |
296 | (any number of digits) | |
8ac170f3 | 297 | \R pass the PCRE_DFA_RESTART option to pcre_dfa_exec() |
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298 | \S output details of memory get/free calls during matching |
299 | \Z pass the PCRE_NOTEOL option to pcre_exec() | |
aa41d2de | 300 | or pcre_dfa_exec() |
495ae4b0 | 301 | \? pass the PCRE_NO_UTF8_CHECK option to |
aa41d2de | 302 | pcre_exec() or pcre_dfa_exec() |
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303 | \>dd start the match at offset dd (any number of digits); |
304 | this sets the startoffset argument for pcre_exec() | |
aa41d2de PH |
305 | or pcre_dfa_exec() |
306 | \<cr> pass the PCRE_NEWLINE_CR option to pcre_exec() | |
307 | or pcre_dfa_exec() | |
308 | \<lf> pass the PCRE_NEWLINE_LF option to pcre_exec() | |
309 | or pcre_dfa_exec() | |
310 | \<crlf> pass the PCRE_NEWLINE_CRLF option to pcre_exec() | |
311 | or pcre_dfa_exec() | |
495ae4b0 | 312 | |
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313 | The escapes that specify line endings are literal strings, exactly as |
314 | shown. A backslash followed by anything else just escapes the anything | |
315 | else. If the very last character is a backslash, it is ignored. This | |
316 | gives a way of passing an empty line as data, since a real empty line | |
317 | terminates the data input. | |
495ae4b0 | 318 | |
8ac170f3 | 319 | If \M is present, pcretest calls pcre_exec() several times, with dif- |
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320 | ferent values in the match_limit and match_limit_recursion fields of |
321 | the pcre_extra data structure, until it finds the minimum numbers for | |
322 | each parameter that allow pcre_exec() to complete. The match_limit num- | |
323 | ber is a measure of the amount of backtracking that takes place, and | |
324 | checking it out can be instructive. For most simple matches, the number | |
325 | is quite small, but for patterns with very large numbers of matching | |
326 | possibilities, it can become large very quickly with increasing length | |
327 | of subject string. The match_limit_recursion number is a measure of how | |
328 | much stack (or, if PCRE is compiled with NO_RECURSE, how much heap) | |
329 | memory is needed to complete the match attempt. | |
330 | ||
331 | When \O is used, the value specified may be higher or lower than the | |
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332 | size set by the -O command line option (or defaulted to 45); \O applies |
333 | only to the call of pcre_exec() for the line in which it appears. | |
334 | ||
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335 | If the /P modifier was present on the pattern, causing the POSIX wrap- |
336 | per API to be used, the only option-setting sequences that have any | |
337 | effect are \B and \Z, causing REG_NOTBOL and REG_NOTEOL, respectively, | |
338 | to be passed to regexec(). | |
495ae4b0 | 339 | |
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340 | The use of \x{hh...} to represent UTF-8 characters is not dependent on |
341 | the use of the /8 modifier on the pattern. It is recognized always. | |
342 | There may be any number of hexadecimal digits inside the braces. The | |
343 | result is from one to six bytes, encoded according to the UTF-8 rules. | |
344 | ||
345 | ||
346 | THE ALTERNATIVE MATCHING FUNCTION | |
347 | ||
348 | By default, pcretest uses the standard PCRE matching function, | |
349 | pcre_exec() to match each data line. From release 6.0, PCRE supports an | |
350 | alternative matching function, pcre_dfa_test(), which operates in a | |
351 | different way, and has some restrictions. The differences between the | |
352 | two functions are described in the pcrematching documentation. | |
353 | ||
354 | If a data line contains the \D escape sequence, or if the command line | |
355 | contains the -dfa option, the alternative matching function is called. | |
356 | This function finds all possible matches at a given point. If, however, | |
357 | the \F escape sequence is present in the data line, it stops after the | |
358 | first match is found. This is always the shortest possible match. | |
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359 | |
360 | ||
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361 | DEFAULT OUTPUT FROM PCRETEST |
362 | ||
363 | This section describes the output when the normal matching function, | |
364 | pcre_exec(), is being used. | |
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365 | |
366 | When a match succeeds, pcretest outputs the list of captured substrings | |
367 | that pcre_exec() returns, starting with number 0 for the string that | |
368 | matched the whole pattern. Otherwise, it outputs "No match" or "Partial | |
369 | match" when pcre_exec() returns PCRE_ERROR_NOMATCH or PCRE_ERROR_PAR- | |
370 | TIAL, respectively, and otherwise the PCRE negative error number. Here | |
371 | is an example of an interactive pcretest run. | |
372 | ||
373 | $ pcretest | |
374 | PCRE version 5.00 07-Sep-2004 | |
375 | ||
376 | re> /^abc(\d+)/ | |
377 | data> abc123 | |
378 | 0: abc123 | |
379 | 1: 123 | |
380 | data> xyz | |
381 | No match | |
382 | ||
383 | If the strings contain any non-printing characters, they are output as | |
384 | \0x escapes, or as \x{...} escapes if the /8 modifier was present on | |
385 | the pattern. If the pattern has the /+ modifier, the output for sub- | |
386 | string 0 is followed by the the rest of the subject string, identified | |
387 | by "0+" like this: | |
388 | ||
389 | re> /cat/+ | |
390 | data> cataract | |
391 | 0: cat | |
392 | 0+ aract | |
393 | ||
394 | If the pattern has the /g or /G modifier, the results of successive | |
395 | matching attempts are output in sequence, like this: | |
396 | ||
397 | re> /\Bi(\w\w)/g | |
398 | data> Mississippi | |
399 | 0: iss | |
400 | 1: ss | |
401 | 0: iss | |
402 | 1: ss | |
403 | 0: ipp | |
404 | 1: pp | |
405 | ||
406 | "No match" is output only if the first match attempt fails. | |
407 | ||
408 | If any of the sequences \C, \G, or \L are present in a data line that | |
409 | is successfully matched, the substrings extracted by the convenience | |
410 | functions are output with C, G, or L after the string number instead of | |
411 | a colon. This is in addition to the normal full list. The string length | |
412 | (that is, the return from the extraction function) is given in paren- | |
413 | theses after each string for \C and \G. | |
414 | ||
415 | Note that while patterns can be continued over several lines (a plain | |
416 | ">" prompt is used for continuations), data lines may not. However new- | |
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417 | lines can be included in data by means of the \n escape (or \r or \r\n |
418 | for those newline settings). | |
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419 | |
420 | ||
8ac170f3 PH |
421 | OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION |
422 | ||
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423 | When the alternative matching function, pcre_dfa_exec(), is used (by |
424 | means of the \D escape sequence or the -dfa command line option), the | |
425 | output consists of a list of all the matches that start at the first | |
8ac170f3 PH |
426 | point in the subject where there is at least one match. For example: |
427 | ||
428 | re> /(tang|tangerine|tan)/ | |
429 | data> yellow tangerine\D | |
430 | 0: tangerine | |
431 | 1: tang | |
432 | 2: tan | |
433 | ||
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434 | (Using the normal matching function on this data finds only "tang".) |
435 | The longest matching string is always given first (and numbered zero). | |
8ac170f3 | 436 | |
aa41d2de | 437 | If /gP is present on the pattern, the search for further matches |
8ac170f3 PH |
438 | resumes at the end of the longest match. For example: |
439 | ||
440 | re> /(tang|tangerine|tan)/g | |
441 | data> yellow tangerine and tangy sultana\D | |
442 | 0: tangerine | |
443 | 1: tang | |
444 | 2: tan | |
445 | 0: tang | |
446 | 1: tan | |
447 | 0: tan | |
448 | ||
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449 | Since the matching function does not support substring capture, the |
450 | escape sequences that are concerned with captured substrings are not | |
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451 | relevant. |
452 | ||
453 | ||
454 | RESTARTING AFTER A PARTIAL MATCH | |
455 | ||
456 | When the alternative matching function has given the PCRE_ERROR_PARTIAL | |
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457 | return, indicating that the subject partially matched the pattern, you |
458 | can restart the match with additional subject data by means of the \R | |
8ac170f3 PH |
459 | escape sequence. For example: |
460 | ||
461 | re> /^?(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)$/ | |
462 | data> 23ja\P\D | |
463 | Partial match: 23ja | |
464 | data> n05\R\D | |
465 | 0: n05 | |
466 | ||
aa41d2de | 467 | For further information about partial matching, see the pcrepartial |
8ac170f3 PH |
468 | documentation. |
469 | ||
470 | ||
495ae4b0 PH |
471 | CALLOUTS |
472 | ||
aa41d2de PH |
473 | If the pattern contains any callout requests, pcretest's callout func- |
474 | tion is called during matching. This works with both matching func- | |
8ac170f3 | 475 | tions. By default, the called function displays the callout number, the |
aa41d2de | 476 | start and current positions in the text at the callout time, and the |
8ac170f3 | 477 | next pattern item to be tested. For example, the output |
495ae4b0 PH |
478 | |
479 | --->pqrabcdef | |
480 | 0 ^ ^ \d | |
481 | ||
aa41d2de PH |
482 | indicates that callout number 0 occurred for a match attempt starting |
483 | at the fourth character of the subject string, when the pointer was at | |
484 | the seventh character of the data, and when the next pattern item was | |
485 | \d. Just one circumflex is output if the start and current positions | |
495ae4b0 PH |
486 | are the same. |
487 | ||
488 | Callouts numbered 255 are assumed to be automatic callouts, inserted as | |
aa41d2de PH |
489 | a result of the /C pattern modifier. In this case, instead of showing |
490 | the callout number, the offset in the pattern, preceded by a plus, is | |
495ae4b0 PH |
491 | output. For example: |
492 | ||
493 | re> /\d?[A-E]\*/C | |
494 | data> E* | |
495 | --->E* | |
496 | +0 ^ \d? | |
497 | +3 ^ [A-E] | |
498 | +8 ^^ \* | |
499 | +10 ^ ^ | |
500 | 0: E* | |
501 | ||
aa41d2de PH |
502 | The callout function in pcretest returns zero (carry on matching) by |
503 | default, but you can use a \C item in a data line (as described above) | |
495ae4b0 PH |
504 | to change this. |
505 | ||
aa41d2de PH |
506 | Inserting callouts can be helpful when using pcretest to check compli- |
507 | cated regular expressions. For further information about callouts, see | |
495ae4b0 PH |
508 | the pcrecallout documentation. |
509 | ||
510 | ||
511 | SAVING AND RELOADING COMPILED PATTERNS | |
512 | ||
aa41d2de | 513 | The facilities described in this section are not available when the |
495ae4b0 PH |
514 | POSIX inteface to PCRE is being used, that is, when the /P pattern mod- |
515 | ifier is specified. | |
516 | ||
517 | When the POSIX interface is not in use, you can cause pcretest to write | |
aa41d2de | 518 | a compiled pattern to a file, by following the modifiers with > and a |
495ae4b0 PH |
519 | file name. For example: |
520 | ||
521 | /pattern/im >/some/file | |
522 | ||
aa41d2de | 523 | See the pcreprecompile documentation for a discussion about saving and |
495ae4b0 PH |
524 | re-using compiled patterns. |
525 | ||
aa41d2de PH |
526 | The data that is written is binary. The first eight bytes are the |
527 | length of the compiled pattern data followed by the length of the | |
528 | optional study data, each written as four bytes in big-endian order | |
529 | (most significant byte first). If there is no study data (either the | |
495ae4b0 | 530 | pattern was not studied, or studying did not return any data), the sec- |
aa41d2de | 531 | ond length is zero. The lengths are followed by an exact copy of the |
495ae4b0 | 532 | compiled pattern. If there is additional study data, this follows imme- |
aa41d2de | 533 | diately after the compiled pattern. After writing the file, pcretest |
495ae4b0 PH |
534 | expects to read a new pattern. |
535 | ||
536 | A saved pattern can be reloaded into pcretest by specifing < and a file | |
aa41d2de PH |
537 | name instead of a pattern. The name of the file must not contain a < |
538 | character, as otherwise pcretest will interpret the line as a pattern | |
495ae4b0 PH |
539 | delimited by < characters. For example: |
540 | ||
541 | re> </some/file | |
542 | Compiled regex loaded from /some/file | |
543 | No study data | |
544 | ||
aa41d2de | 545 | When the pattern has been loaded, pcretest proceeds to read data lines |
495ae4b0 PH |
546 | in the usual way. |
547 | ||
aa41d2de PH |
548 | You can copy a file written by pcretest to a different host and reload |
549 | it there, even if the new host has opposite endianness to the one on | |
550 | which the pattern was compiled. For example, you can compile on an i86 | |
495ae4b0 PH |
551 | machine and run on a SPARC machine. |
552 | ||
aa41d2de PH |
553 | File names for saving and reloading can be absolute or relative, but |
554 | note that the shell facility of expanding a file name that starts with | |
495ae4b0 PH |
555 | a tilde (~) is not available. |
556 | ||
aa41d2de PH |
557 | The ability to save and reload files in pcretest is intended for test- |
558 | ing and experimentation. It is not intended for production use because | |
559 | only a single pattern can be written to a file. Furthermore, there is | |
560 | no facility for supplying custom character tables for use with a | |
561 | reloaded pattern. If the original pattern was compiled with custom | |
562 | tables, an attempt to match a subject string using a reloaded pattern | |
563 | is likely to cause pcretest to crash. Finally, if you attempt to load | |
495ae4b0 PH |
564 | a file that is not in the correct format, the result is undefined. |
565 | ||
566 | ||
567 | AUTHOR | |
568 | ||
8ac170f3 | 569 | Philip Hazel |
495ae4b0 PH |
570 | University Computing Service, |
571 | Cambridge CB2 3QG, England. | |
572 | ||
aa41d2de PH |
573 | Last updated: 29 June 2006 |
574 | Copyright (c) 1997-2006 University of Cambridge. |