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1: <html> 2: <head> 3: <title>pcregrep specification</title> 4: </head> 5: <body bgcolor="#FFFFFF" text="#00005A" link="#0066FF" alink="#3399FF" vlink="#2222BB"> 6: <h1>pcregrep man page</h1> 7:  8: Return to the <a href="index.html">PCRE index page</a>. 9:  10:  11: This page is part of the PCRE HTML documentation. It was generated automatically 12: from the original man page. If there is any nonsense in it, please consult the 13: man page, in case the conversion went wrong. 14:   15: <ul> 16: <li><a name="TOC1" href="#SEC1">SYNOPSIS</a> 17: <li><a name="TOC2" href="#SEC2">DESCRIPTION</a> 18: <li><a name="TOC3" href="#SEC3">SUPPORT FOR COMPRESSED FILES</a> 19: <li><a name="TOC4" href="#SEC4">BINARY FILES</a> 20: <li><a name="TOC5" href="#SEC5">OPTIONS</a> 21: <li><a name="TOC6" href="#SEC6">ENVIRONMENT VARIABLES</a> 22: <li><a name="TOC7" href="#SEC7">NEWLINES</a> 23: <li><a name="TOC8" href="#SEC8">OPTIONS COMPATIBILITY</a> 24: <li><a name="TOC9" href="#SEC9">OPTIONS WITH DATA</a> 25: <li><a name="TOC10" href="#SEC10">MATCHING ERRORS</a> 26: <li><a name="TOC11" href="#SEC11">DIAGNOSTICS</a> 27: <li><a name="TOC12" href="#SEC12">SEE ALSO</a> 28: <li><a name="TOC13" href="#SEC13">AUTHOR</a> 29: <li><a name="TOC14" href="#SEC14">REVISION</a> 30: </ul> 31:  <a name="SEC1" href="#TOC1">SYNOPSIS</a>  32:  33: pcregrep [options] [long options] [pattern] [path1 path2 ...] 34:  35:  <a name="SEC2" href="#TOC1">DESCRIPTION</a>  36:  37: pcregrep searches files for character patterns, in the same way as other 38: grep commands do, but it uses the PCRE regular expression library to support 39: patterns that are compatible with the regular expressions of Perl 5. See 40: <a href="pcrepattern.html">pcrepattern(3)</a> 41: for a full description of syntax and semantics of the regular expressions 42: that PCRE supports. 43:  44:  45: Patterns, whether supplied on the command line or in a separate file, are given 46: without delimiters. For example: 47: <pre> 48: pcregrep Thursday /etc/motd 49: </pre> 50: If you attempt to use delimiters (for example, by surrounding a pattern with 51: slashes, as is common in Perl scripts), they are interpreted as part of the 52: pattern. Quotes can of course be used to delimit patterns on the command line 53: because they are interpreted by the shell, and indeed quotes are required if a 54: pattern contains white space or shell metacharacters. 55:  56:  57: The first argument that follows any option settings is treated as the single 58: pattern to be matched when neither -e nor -f is present. 59: Conversely, when one or both of these options are used to specify patterns, all 60: arguments are treated as path names. At least one of -e, -f, or an 61: argument pattern must be provided. 62:  63:  64: If no files are specified, pcregrep reads the standard input. The 65: standard input can also be referenced by a name consisting of a single hyphen. 66: For example: 67: <pre> 68: pcregrep some-pattern /file1 - /file3 69: </pre> 70: By default, each line that matches a pattern is copied to the standard 71: output, and if there is more than one file, the file name is output at the 72: start of each line, followed by a colon. However, there are options that can 73: change how pcregrep behaves. In particular, the -M option makes it 74: possible to search for patterns that span line boundaries. What defines a line 75: boundary is controlled by the -N (--newline) option. 76:  77:  78: The amount of memory used for buffering files that are being scanned is 79: controlled by a parameter that can be set by the --buffer-size option. 80: The default value for this parameter is specified when pcregrep is built, 81: with the default default being 20K. A block of memory three times this size is 82: used (to allow for buffering "before" and "after" lines). An error occurs if a 83: line overflows the buffer. 84:  85:  86: Patterns can be no longer than 8K or BUFSIZ bytes, whichever is the greater. 87: BUFSIZ is defined in <stdio.h>. When there is more than one pattern 88: (specified by the use of -e and/or -f), each pattern is applied to 89: each line in the order in which they are defined, except that all the -e 90: patterns are tried before the -f patterns. 91:  92:  93: By default, as soon as one pattern matches a line, no further patterns are 94: considered. However, if --colour (or --color) is used to colour the 95: matching substrings, or if --only-matching, --file-offsets, or 96: --line-offsets is used to output only the part of the line that matched 97: (either shown literally, or as an offset), scanning resumes immediately 98: following the match, so that further matches on the same line can be found. If 99: there are multiple patterns, they are all tried on the remainder of the line, 100: but patterns that follow the one that matched are not tried on the earlier part 101: of the line. 102:  103:  104: This behaviour means that the order in which multiple patterns are specified 105: can affect the output when one of the above options is used. This is no longer 106: the same behaviour as GNU grep, which now manages to display earlier matches 107: for later patterns (as long as there is no overlap). 108:  109:  110: Patterns that can match an empty string are accepted, but empty string 111: matches are never recognized. An example is the pattern "(super)?(man)?", in 112: which all components are optional. This pattern finds all occurrences of both 113: "super" and "man"; the output differs from matching with "super|man" when only 114: the matching substrings are being shown. 115:  116:  117: If the LC_ALL or LC_CTYPE environment variable is set, 118: pcregrep uses the value to set a locale when calling the PCRE library. 119: The --locale option can be used to override this. 120:  121:  <a name="SEC3" href="#TOC1">SUPPORT FOR COMPRESSED FILES</a>  122:  123: It is possible to compile pcregrep so that it uses libz or 124: libbz2 to read files whose names end in .gz or .bz2, 125: respectively. You can find out whether your binary has support for one or both 126: of these file types by running it with the --help option. If the 127: appropriate support is not present, files are treated as plain text. The 128: standard input is always so treated. 129:  130:  <a name="SEC4" href="#TOC1">BINARY FILES</a>  131:  132: By default, a file that contains a binary zero byte within the first 1024 bytes 133: is identified as a binary file, and is processed specially. (GNU grep also 134: identifies binary files in this manner.) See the --binary-files option 135: for a means of changing the way binary files are handled. 136:  137:  <a name="SEC5" href="#TOC1">OPTIONS</a>  138:  139: The order in which some of the options appear can affect the output. For 140: example, both the -h and -l options affect the printing of file 141: names. Whichever comes later in the command line will be the one that takes 142: effect. Similarly, except where noted below, if an option is given twice, the 143: later setting is used. Numerical values for options may be followed by K or M, 144: to signify multiplication by 1024 or 1024*1024 respectively. 145:  146:  147: -- 148: This terminates the list of options. It is useful if the next item on the 149: command line starts with a hyphen but is not an option. This allows for the 150: processing of patterns and filenames that start with hyphens. 151:  152:  153: -A number, --after-context=number 154: Output number lines of context after each matching line. If filenames 155: and/or line numbers are being output, a hyphen separator is used instead of a 156: colon for the context lines. A line containing "--" is output between each 157: group of lines, unless they are in fact contiguous in the input file. The value 158: of number is expected to be relatively small. However, pcregrep 159: guarantees to have up to 8K of following text available for context output. 160:  161:  162: -a, --text 163: Treat binary files as text. This is equivalent to 164: --binary-files=text. 165:  166:  167: -B number, --before-context=number 168: Output number lines of context before each matching line. If filenames 169: and/or line numbers are being output, a hyphen separator is used instead of a 170: colon for the context lines. A line containing "--" is output between each 171: group of lines, unless they are in fact contiguous in the input file. The value 172: of number is expected to be relatively small. However, pcregrep 173: guarantees to have up to 8K of preceding text available for context output. 174:  175:  176: --binary-files=word 177: Specify how binary files are to be processed. If the word is "binary" (the 178: default), pattern matching is performed on binary files, but the only output is 179: "Binary file <name> matches" when a match succeeds. If the word is "text", 180: which is equivalent to the -a or --text option, binary files are 181: processed in the same way as any other file. In this case, when a match 182: succeeds, the output may be binary garbage, which can have nasty effects if 183: sent to a terminal. If the word is "without-match", which is equivalent to the 184: -I option, binary files are not processed at all; they are assumed not to 185: be of interest. 186:  187:  188: --buffer-size=number 189: Set the parameter that controls how much memory is used for buffering files 190: that are being scanned. 191:  192:  193: -C number, --context=number 194: Output number lines of context both before and after each matching line. 195: This is equivalent to setting both -A and -B to the same value. 196:  197:  198: -c, --count 199: Do not output individual lines from the files that are being scanned; instead 200: output the number of lines that would otherwise have been shown. If no lines 201: are selected, the number zero is output. If several files are are being 202: scanned, a count is output for each of them. However, if the 203: --files-with-matches option is also used, only those files whose counts 204: are greater than zero are listed. When -c is used, the -A, 205: -B, and -C options are ignored. 206:  207:  208: --colour, --color 209: If this option is given without any data, it is equivalent to "--colour=auto". 210: If data is required, it must be given in the same shell item, separated by an 211: equals sign. 212:  213:  214: --colour=value, --color=value 215: This option specifies under what circumstances the parts of a line that matched 216: a pattern should be coloured in the output. By default, the output is not 217: coloured. The value (which is optional, see above) may be "never", "always", or 218: "auto". In the latter case, colouring happens only if the standard output is 219: connected to a terminal. More resources are used when colouring is enabled, 220: because pcregrep has to search for all possible matches in a line, not 221: just one, in order to colour them all. 222:   223:   224: The colour that is used can be specified by setting the environment variable 225: PCREGREP_COLOUR or PCREGREP_COLOR. The value of this variable should be a 226: string of two numbers, separated by a semicolon. They are copied directly into 227: the control string for setting colour on a terminal, so it is your 228: responsibility to ensure that they make sense. If neither of the environment 229: variables is set, the default is "1;31", which gives red. 230:  231:  232: -D action, --devices=action 233: If an input path is not a regular file or a directory, "action" specifies how 234: it is to be processed. Valid values are "read" (the default) or "skip" 235: (silently skip the path). 236:  237:  238: -d action, --directories=action 239: If an input path is a directory, "action" specifies how it is to be processed. 240: Valid values are "read" (the default in non-Windows environments, for 241: compatibility with GNU grep), "recurse" (equivalent to the -r option), or 242: "skip" (silently skip the path, the default in Windows environments). In the 243: "read" case, directories are read as if they were ordinary files. In some 244: operating systems the effect of reading a directory like this is an immediate 245: end-of-file; in others it may provoke an error. 246:  247:  248: -e pattern, --regex=pattern, --regexp=pattern 249: Specify a pattern to be matched. This option can be used multiple times in 250: order to specify several patterns. It can also be used as a way of specifying a 251: single pattern that starts with a hyphen. When -e is used, no argument 252: pattern is taken from the command line; all arguments are treated as file 253: names. There is no limit to the number of patterns. They are applied to each 254: line in the order in which they are defined until one matches. 255:   256:   257: If -f is used with -e, the command line patterns are matched first, 258: followed by the patterns from the file(s), independent of the order in which 259: these options are specified. Note that multiple use of -e is not the same 260: as a single pattern with alternatives. For example, X|Y finds the first 261: character in a line that is X or Y, whereas if the two patterns are given 262: separately, with X first, pcregrep finds X if it is present, even if it 263: follows Y in the line. It finds Y only if there is no X in the line. This 264: matters only if you are using -o or --colo(u)r to show the part(s) 265: of the line that matched. 266:  267:  268: --exclude=pattern 269: Files (but not directories) whose names match the pattern are skipped without 270: being processed. This applies to all files, whether listed on the command line, 271: obtained from --file-list, or by scanning a directory. The pattern is a 272: PCRE regular expression, and is matched against the final component of the file 273: name, not the entire path. The -F, -w, and -x options do not 274: apply to this pattern. The option may be given any number of times in order to 275: specify multiple patterns. If a file name matches both an --include 276: and an --exclude pattern, it is excluded. There is no short form for this 277: option. 278:  279:  280: --exclude-from=filename 281: Treat each non-empty line of the file as the data for an --exclude 282: option. What constitutes a newline when reading the file is the operating 283: system's default. The --newline option has no effect on this option. This 284: option may be given more than once in order to specify a number of files to 285: read. 286:  287:  288: --exclude-dir=pattern 289: Directories whose names match the pattern are skipped without being processed, 290: whatever the setting of the --recursive option. This applies to all 291: directories, whether listed on the command line, obtained from 292: --file-list, or by scanning a parent directory. The pattern is a PCRE 293: regular expression, and is matched against the final component of the directory 294: name, not the entire path. The -F, -w, and -x options do not 295: apply to this pattern. The option may be given any number of times in order to 296: specify more than one pattern. If a directory matches both --include-dir 297: and --exclude-dir, it is excluded. There is no short form for this 298: option. 299:  300:  301: -F, --fixed-strings 302: Interpret each data-matching pattern as a list of fixed strings, separated by 303: newlines, instead of as a regular expression. What constitutes a newline for 304: this purpose is controlled by the --newline option. The -w (match 305: as a word) and -x (match whole line) options can be used with -F. 306: They apply to each of the fixed strings. A line is selected if any of the fixed 307: strings are found in it (subject to -w or -x, if present). This 308: option applies only to the patterns that are matched against the contents of 309: files; it does not apply to patterns specified by any of the --include or 310: --exclude options. 311:  312:  313: -f filename, --file=filename 314: Read patterns from the file, one per line, and match them against 315: each line of input. What constitutes a newline when reading the file is the 316: operating system's default. The --newline option has no effect on this 317: option. Trailing white space is removed from each line, and blank lines are 318: ignored. An empty file contains no patterns and therefore matches nothing. See 319: also the comments about multiple patterns versus a single pattern with 320: alternatives in the description of -e above. 321:   322:   323: If this option is given more than once, all the specified files are 324: read. A data line is output if any of the patterns match it. A filename can 325: be given as "-" to refer to the standard input. When -f is used, patterns 326: specified on the command line using -e may also be present; they are 327: tested before the file's patterns. However, no other pattern is taken from the 328: command line; all arguments are treated as the names of paths to be searched. 329:  330:  331: --file-list=filename 332: Read a list of files and/or directories that are to be scanned from the given 333: file, one per line. Trailing white space is removed from each line, and blank 334: lines are ignored. These paths are processed before any that are listed on the 335: command line. The filename can be given as "-" to refer to the standard input. 336: If --file and --file-list are both specified as "-", patterns are 337: read first. This is useful only when the standard input is a terminal, from 338: which further lines (the list of files) can be read after an end-of-file 339: indication. If this option is given more than once, all the specified files are 340: read. 341:  342:  343: --file-offsets 344: Instead of showing lines or parts of lines that match, show each match as an 345: offset from the start of the file and a length, separated by a comma. In this 346: mode, no context is shown. That is, the -A, -B, and -C 347: options are ignored. If there is more than one match in a line, each of them is 348: shown separately. This option is mutually exclusive with --line-offsets 349: and --only-matching. 350:  351:  352: -H, --with-filename 353: Force the inclusion of the filename at the start of output lines when searching 354: a single file. By default, the filename is not shown in this case. For matching 355: lines, the filename is followed by a colon; for context lines, a hyphen 356: separator is used. If a line number is also being output, it follows the file 357: name. 358:  359:  360: -h, --no-filename 361: Suppress the output filenames when searching multiple files. By default, 362: filenames are shown when multiple files are searched. For matching lines, the 363: filename is followed by a colon; for context lines, a hyphen separator is used. 364: If a line number is also being output, it follows the file name. 365:  366:  367: --help 368: Output a help message, giving brief details of the command options and file 369: type support, and then exit. Anything else on the command line is 370: ignored. 371:  372:  373: -I 374: Treat binary files as never matching. This is equivalent to 375: --binary-files=without-match. 376:  377:  378: -i, --ignore-case 379: Ignore upper/lower case distinctions during comparisons. 380:  381:  382: --include=pattern 383: If any --include patterns are specified, the only files that are 384: processed are those that match one of the patterns (and do not match an 385: --exclude pattern). This option does not affect directories, but it 386: applies to all files, whether listed on the command line, obtained from 387: --file-list, or by scanning a directory. The pattern is a PCRE regular 388: expression, and is matched against the final component of the file name, not 389: the entire path. The -F, -w, and -x options do not apply to 390: this pattern. The option may be given any number of times. If a file name 391: matches both an --include and an --exclude pattern, it is excluded. 392: There is no short form for this option. 393:  394:  395: --include-from=filename 396: Treat each non-empty line of the file as the data for an --include 397: option. What constitutes a newline for this purpose is the operating system's 398: default. The --newline option has no effect on this option. This option 399: may be given any number of times; all the files are read. 400:  401:  402: --include-dir=pattern 403: If any --include-dir patterns are specified, the only directories that 404: are processed are those that match one of the patterns (and do not match an 405: --exclude-dir pattern). This applies to all directories, whether listed 406: on the command line, obtained from --file-list, or by scanning a parent 407: directory. The pattern is a PCRE regular expression, and is matched against the 408: final component of the directory name, not the entire path. The -F, 409: -w, and -x options do not apply to this pattern. The option may be 410: given any number of times. If a directory matches both --include-dir and 411: --exclude-dir, it is excluded. There is no short form for this option. 412:  413:  414: -L, --files-without-match 415: Instead of outputting lines from the files, just output the names of the files 416: that do not contain any lines that would have been output. Each file name is 417: output once, on a separate line. 418:  419:  420: -l, --files-with-matches 421: Instead of outputting lines from the files, just output the names of the files 422: containing lines that would have been output. Each file name is output 423: once, on a separate line. Searching normally stops as soon as a matching line 424: is found in a file. However, if the -c (count) option is also used, 425: matching continues in order to obtain the correct count, and those files that 426: have at least one match are listed along with their counts. Using this option 427: with -c is a way of suppressing the listing of files with no matches. 428:  429:  430: --label=name 431: This option supplies a name to be used for the standard input when file names 432: are being output. If not supplied, "(standard input)" is used. There is no 433: short form for this option. 434:  435:  436: --line-buffered 437: When this option is given, input is read and processed line by line, and the 438: output is flushed after each write. By default, input is read in large chunks, 439: unless pcregrep can determine that it is reading from a terminal (which 440: is currently possible only in Unix-like environments). Output to terminal is 441: normally automatically flushed by the operating system. This option can be 442: useful when the input or output is attached to a pipe and you do not want 443: pcregrep to buffer up large amounts of data. However, its use will affect 444: performance, and the -M (multiline) option ceases to work. 445:  446:  447: --line-offsets 448: Instead of showing lines or parts of lines that match, show each match as a 449: line number, the offset from the start of the line, and a length. The line 450: number is terminated by a colon (as usual; see the -n option), and the 451: offset and length are separated by a comma. In this mode, no context is shown. 452: That is, the -A, -B, and -C options are ignored. If there is 453: more than one match in a line, each of them is shown separately. This option is 454: mutually exclusive with --file-offsets and --only-matching. 455:  456:  457: --locale=locale-name 458: This option specifies a locale to be used for pattern matching. It overrides 459: the value in the LC_ALL or LC_CTYPE environment variables. If no 460: locale is specified, the PCRE library's default (usually the "C" locale) is 461: used. There is no short form for this option. 462:  463:  464: --match-limit=number 465: Processing some regular expression patterns can require a very large amount of 466: memory, leading in some cases to a program crash if not enough is available. 467: Other patterns may take a very long time to search for all possible matching 468: strings. The pcre_exec() function that is called by pcregrep to do 469: the matching has two parameters that can limit the resources that it uses. 470:   471:   472: The --match-limit option provides a means of limiting resource usage 473: when processing patterns that are not going to match, but which have a very 474: large number of possibilities in their search trees. The classic example is a 475: pattern that uses nested unlimited repeats. Internally, PCRE uses a function 476: called match() which it calls repeatedly (sometimes recursively). The 477: limit set by --match-limit is imposed on the number of times this 478: function is called during a match, which has the effect of limiting the amount 479: of backtracking that can take place. 480:   481:   482: The --recursion-limit option is similar to --match-limit, but 483: instead of limiting the total number of times that match() is called, it 484: limits the depth of recursive calls, which in turn limits the amount of memory 485: that can be used. The recursion depth is a smaller number than the total number 486: of calls, because not all calls to match() are recursive. This limit is 487: of use only if it is set smaller than --match-limit. 488:   489:   490: There are no short forms for these options. The default settings are specified 491: when the PCRE library is compiled, with the default default being 10 million. 492:  493:  494: -M, --multiline 495: Allow patterns to match more than one line. When this option is given, patterns 496: may usefully contain literal newline characters and internal occurrences of ^ 497: and $ characters. The output for a successful match may consist of more than 498: one line, the last of which is the one in which the match ended. If the matched 499: string ends with a newline sequence the output ends at the end of that line. 500:   501:   502: When this option is set, the PCRE library is called in "multiline" mode. 503: There is a limit to the number of lines that can be matched, imposed by the way 504: that pcregrep buffers the input file as it scans it. However, 505: pcregrep ensures that at least 8K characters or the rest of the document 506: (whichever is the shorter) are available for forward matching, and similarly 507: the previous 8K characters (or all the previous characters, if fewer than 8K) 508: are guaranteed to be available for lookbehind assertions. This option does not 509: work when input is read line by line (see \fP--line-buffered\fP.) 510:  511:  512: -N newline-type, --newline=newline-type 513: The PCRE library supports five different conventions for indicating 514: the ends of lines. They are the single-character sequences CR (carriage return) 515: and LF (linefeed), the two-character sequence CRLF, an "anycrlf" convention, 516: which recognizes any of the preceding three types, and an "any" convention, in 517: which any Unicode line ending sequence is assumed to end a line. The Unicode 518: sequences are the three just mentioned, plus VT (vertical tab, U+000B), FF 519: (form feed, U+000C), NEL (next line, U+0085), LS (line separator, U+2028), and 520: PS (paragraph separator, U+2029). 521:   522:   523: When the PCRE library is built, a default line-ending sequence is specified. 524: This is normally the standard sequence for the operating system. Unless 525: otherwise specified by this option, pcregrep uses the library's default. 526: The possible values for this option are CR, LF, CRLF, ANYCRLF, or ANY. This 527: makes it possible to use pcregrep to scan files that have come from other 528: environments without having to modify their line endings. If the data that is 529: being scanned does not agree with the convention set by this option, 530: pcregrep may behave in strange ways. Note that this option does not 531: apply to files specified by the -f, --exclude-from, or 532: --include-from options, which are expected to use the operating system's 533: standard newline sequence. 534:  535:  536: -n, --line-number 537: Precede each output line by its line number in the file, followed by a colon 538: for matching lines or a hyphen for context lines. If the filename is also being 539: output, it precedes the line number. This option is forced if 540: --line-offsets is used. 541:  542:  543: --no-jit 544: If the PCRE library is built with support for just-in-time compiling (which 545: speeds up matching), pcregrep automatically makes use of this, unless it 546: was explicitly disabled at build time. This option can be used to disable the 547: use of JIT at run time. It is provided for testing and working round problems. 548: It should never be needed in normal use. 549:  550:  551: -o, --only-matching 552: Show only the part of the line that matched a pattern instead of the whole 553: line. In this mode, no context is shown. That is, the -A, -B, and 554: -C options are ignored. If there is more than one match in a line, each 555: of them is shown separately. If -o is combined with -v (invert the 556: sense of the match to find non-matching lines), no output is generated, but the 557: return code is set appropriately. If the matched portion of the line is empty, 558: nothing is output unless the file name or line number are being printed, in 559: which case they are shown on an otherwise empty line. This option is mutually 560: exclusive with --file-offsets and --line-offsets. 561:  562:  563: -onumber, --only-matching=number 564: Show only the part of the line that matched the capturing parentheses of the 565: given number. Up to 32 capturing parentheses are supported, and -o0 is 566: equivalent to -o without a number. Because these options can be given 567: without an argument (see above), if an argument is present, it must be given in 568: the same shell item, for example, -o3 or --only-matching=2. The comments given 569: for the non-argument case above also apply to this case. If the specified 570: capturing parentheses do not exist in the pattern, or were not set in the 571: match, nothing is output unless the file name or line number are being printed. 572:   573:   574: If this option is given multiple times, multiple substrings are output, in the 575: order the options are given. For example, -o3 -o1 -o3 causes the substrings 576: matched by capturing parentheses 3 and 1 and then 3 again to be output. By 577: default, there is no separator (but see the next option). 578:  579:  580: --om-separator=text 581: Specify a separating string for multiple occurrences of -o. The default 582: is an empty string. Separating strings are never coloured. 583:  584:  585: -q, --quiet 586: Work quietly, that is, display nothing except error messages. The exit 587: status indicates whether or not any matches were found. 588:  589:  590: -r, --recursive 591: If any given path is a directory, recursively scan the files it contains, 592: taking note of any --include and --exclude settings. By default, a 593: directory is read as a normal file; in some operating systems this gives an 594: immediate end-of-file. This option is a shorthand for setting the -d 595: option to "recurse". 596:  597:  598: --recursion-limit=number 599: See --match-limit above. 600:  601:  602: -s, --no-messages 603: Suppress error messages about non-existent or unreadable files. Such files are 604: quietly skipped. However, the return code is still 2, even if matches were 605: found in other files. 606:  607:  608: -u, --utf-8 609: Operate in UTF-8 mode. This option is available only if PCRE has been compiled 610: with UTF-8 support. All patterns (including those for any --exclude and 611: --include options) and all subject lines that are scanned must be valid 612: strings of UTF-8 characters. 613:  614:  615: -V, --version 616: Write the version numbers of pcregrep and the PCRE library to the 617: standard output and then exit. Anything else on the command line is 618: ignored. 619:  620:  621: -v, --invert-match 622: Invert the sense of the match, so that lines which do not match any of 623: the patterns are the ones that are found. 624:  625:  626: -w, --word-regex, --word-regexp 627: Force the patterns to match only whole words. This is equivalent to having \b 628: at the start and end of the pattern. This option applies only to the patterns 629: that are matched against the contents of files; it does not apply to patterns 630: specified by any of the --include or --exclude options. 631:  632:  633: -x, --line-regex, --line-regexp 634: Force the patterns to be anchored (each must start matching at the beginning of 635: a line) and in addition, require them to match entire lines. This is equivalent 636: to having ^ and $ characters at the start and end of each alternative branch in 637: every pattern. This option applies only to the patterns that are matched 638: against the contents of files; it does not apply to patterns specified by any 639: of the --include or --exclude options. 640:  641:  <a name="SEC6" href="#TOC1">ENVIRONMENT VARIABLES</a>  642:  643: The environment variables LC_ALL and LC_CTYPE are examined, in that 644: order, for a locale. The first one that is set is used. This can be overridden 645: by the --locale option. If no locale is set, the PCRE library's default 646: (usually the "C" locale) is used. 647:  648:  <a name="SEC7" href="#TOC1">NEWLINES</a>  649:  650: The -N (--newline) option allows pcregrep to scan files with 651: different newline conventions from the default. Any parts of the input files 652: that are written to the standard output are copied identically, with whatever 653: newline sequences they have in the input. However, the setting of this option 654: does not affect the interpretation of files specified by the -f, 655: --exclude-from, or --include-from options, which are assumed to use 656: the operating system's standard newline sequence, nor does it affect the way in 657: which pcregrep writes informational messages to the standard error and 658: output streams. For these it uses the string "\n" to indicate newlines, 659: relying on the C I/O library to convert this to an appropriate sequence. 660:  661:  <a name="SEC8" href="#TOC1">OPTIONS COMPATIBILITY</a>  662:  663: Many of the short and long forms of pcregrep's options are the same 664: as in the GNU grep program. Any long option of the form 665: --xxx-regexp (GNU terminology) is also available as --xxx-regex 666: (PCRE terminology). However, the --file-list, --file-offsets, 667: --include-dir, --line-offsets, --locale, --match-limit, 668: -M, --multiline, -N, --newline, --om-separator, 669: --recursion-limit, -u, and --utf-8 options are specific to 670: pcregrep, as is the use of the --only-matching option with a 671: capturing parentheses number. 672:  673:  674: Although most of the common options work the same way, a few are different in 675: pcregrep. For example, the --include option's argument is a glob 676: for GNU grep, but a regular expression for pcregrep. If both the 677: -c and -l options are given, GNU grep lists only file names, 678: without counts, but pcregrep gives the counts. 679:  680:  <a name="SEC9" href="#TOC1">OPTIONS WITH DATA</a>  681:  682: There are four different ways in which an option with data can be specified. 683: If a short form option is used, the data may follow immediately, or (with one 684: exception) in the next command line item. For example: 685: <pre> 686: -f/some/file 687: -f /some/file 688: </pre> 689: The exception is the -o option, which may appear with or without data. 690: Because of this, if data is present, it must follow immediately in the same 691: item, for example -o3. 692:  693:  694: If a long form option is used, the data may appear in the same command line 695: item, separated by an equals character, or (with two exceptions) it may appear 696: in the next command line item. For example: 697: <pre> 698: --file=/some/file 699: --file /some/file 700: </pre> 701: Note, however, that if you want to supply a file name beginning with ~ as data 702: in a shell command, and have the shell expand ~ to a home directory, you must 703: separate the file name from the option, because the shell does not treat ~ 704: specially unless it is at the start of an item. 705:  706:  707: The exceptions to the above are the --colour (or --color) and 708: --only-matching options, for which the data is optional. If one of these 709: options does have data, it must be given in the first form, using an equals 710: character. Otherwise pcregrep will assume that it has no data. 711:  712:  <a name="SEC10" href="#TOC1">MATCHING ERRORS</a>  713:  714: It is possible to supply a regular expression that takes a very long time to 715: fail to match certain lines. Such patterns normally involve nested indefinite 716: repeats, for example: (a+)*\d when matched against a line of a's with no final 717: digit. The PCRE matching function has a resource limit that causes it to abort 718: in these circumstances. If this happens, pcregrep outputs an error 719: message and the line that caused the problem to the standard error stream. If 720: there are more than 20 such errors, pcregrep gives up. 721:  722:  723: The --match-limit option of pcregrep can be used to set the overall 724: resource limit; there is a second option called --recursion-limit that 725: sets a limit on the amount of memory (usually stack) that is used (see the 726: discussion of these options above). 727:  728:  <a name="SEC11" href="#TOC1">DIAGNOSTICS</a>  729:  730: Exit status is 0 if any matches were found, 1 if no matches were found, and 2 731: for syntax errors, overlong lines, non-existent or inaccessible files (even if 732: matches were found in other files) or too many matching errors. Using the 733: -s option to suppress error messages about inaccessible files does not 734: affect the return code. 735:  736:  <a name="SEC12" href="#TOC1">SEE ALSO</a>  737:  738: pcrepattern(3), pcresyntax(3), pcretest(1). 739:  740:  <a name="SEC13" href="#TOC1">AUTHOR</a>  741:  742: Philip Hazel 743:   744: University Computing Service 745:   746: Cambridge CB2 3QH, England. 747:   748:  749:  <a name="SEC14" href="#TOC1">REVISION</a>  750:  751: Last updated: 13 September 2012 752:   753: Copyright © 1997-2012 University of Cambridge. 754:   755:  756: Return to the <a href="index.html">PCRE index page</a>. 757: 