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1  README file for PCRE (Perl-compatible regular expressions)  README file for PCRE (Perl-compatible regular expression library)
2  ----------------------------------------------------------  -----------------------------------------------------------------
3    
4  The distribution should contain the following files:  The latest release of PCRE is always available from
5    
6      ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/pcre-xxx.tar.gz
7    
8    Please read the NEWS file if you are upgrading from a previous release.
9    
10    
11    The PCRE APIs
12    -------------
13    
14    PCRE is written in C, and it has its own API. The distribution now includes a
15    set of C++ wrapper functions, courtesy of Google Inc. (see the pcrecpp man page
16    for details).
17    
18    Also included are a set of C wrapper functions that are based on the POSIX
19    API. These end up in the library called libpcreposix. Note that this just
20    provides a POSIX calling interface to PCRE: the regular expressions themselves
21    still follow Perl syntax and semantics. The header file for the POSIX-style
22    functions is called pcreposix.h. The official POSIX name is regex.h, but I
23    didn't want to risk possible problems with existing files of that name by
24    distributing it that way. To use it with an existing program that uses the
25    POSIX API, it will have to be renamed or pointed at by a link.
26    
27    If you are using the POSIX interface to PCRE and there is already a POSIX regex
28    library installed on your system, you must take care when linking programs to
29    ensure that they link with PCRE's libpcreposix library. Otherwise they may pick
30    up the "real" POSIX functions of the same name.
31    
32    
33    Documentation for PCRE
34    ----------------------
35    
36    If you install PCRE in the normal way, you will end up with an installed set of
37    man pages whose names all start with "pcre". The one that is just called "pcre"
38    lists all the others. In addition to these man pages, the PCRE documentation is
39    supplied in two other forms; however, as there is no standard place to install
40    them, they are left in the doc directory of the unpacked source distribution.
41    These forms are:
42    
43      1. Files called doc/pcre.txt, doc/pcregrep.txt, and doc/pcretest.txt. The
44         first of these is a concatenation of the text forms of all the section 3
45         man pages except those that summarize individual functions. The other two
46         are the text forms of the section 1 man pages for the pcregrep and
47         pcretest commands. Text forms are provided for ease of scanning with text
48         editors or similar tools.
49    
50      2. A subdirectory called doc/html contains all the documentation in HTML
51         form, hyperlinked in various ways, and rooted in a file called
52         doc/index.html.
53    
54    
55    Contributions by users of PCRE
56    ------------------------------
57    
58    You can find contributions from PCRE users in the directory
59    
60      ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/Contrib
61    
62    where there is also a README file giving brief descriptions of what they are.
63    Several of them provide support for compiling PCRE on various flavours of
64    Windows systems (I myself do not use Windows). Some are complete in themselves;
65    others are pointers to URLs containing relevant files.
66    
67    
68    Building PCRE on a Unix-like system
69    -----------------------------------
70    
71    If you are using HP's ANSI C++ compiler (aCC), please see the special note
72    in the section entitled "Using HP's ANSI C++ compiler (aCC)" below.
73    
74    To build PCRE on a Unix-like system, first run the "configure" command from the
75    PCRE distribution directory, with your current directory set to the directory
76    where you want the files to be created. This command is a standard GNU
77    "autoconf" configuration script, for which generic instructions are supplied in
78    INSTALL.
79    
80    Most commonly, people build PCRE within its own distribution directory, and in
81    this case, on many systems, just running "./configure" is sufficient, but the
82    usual methods of changing standard defaults are available. For example:
83    
84    CFLAGS='-O2 -Wall' ./configure --prefix=/opt/local
85    
86    specifies that the C compiler should be run with the flags '-O2 -Wall' instead
87    of the default, and that "make install" should install PCRE under /opt/local
88    instead of the default /usr/local.
89    
90    If you want to build in a different directory, just run "configure" with that
91    directory as current. For example, suppose you have unpacked the PCRE source
92    into /source/pcre/pcre-xxx, but you want to build it in /build/pcre/pcre-xxx:
93    
94    cd /build/pcre/pcre-xxx
95    /source/pcre/pcre-xxx/configure
96    
97    PCRE is written in C and is normally compiled as a C library. However, it is
98    possible to build it as a C++ library, though the provided building apparatus
99    does not have any features to support this.
100    
101    There are some optional features that can be included or omitted from the PCRE
102    library. You can read more about them in the pcrebuild man page.
103    
104    . If you want to suppress the building of the C++ wrapper library, you can add
105      --disable-cpp to the "configure" command. Otherwise, when "configure" is run,
106      will try to find a C++ compiler and C++ header files, and if it succeeds, it
107      will try to build the C++ wrapper.
108    
109    . If you want to make use of the support for UTF-8 character strings in PCRE,
110      you must add --enable-utf8 to the "configure" command. Without it, the code
111      for handling UTF-8 is not included in the library. (Even when included, it
112      still has to be enabled by an option at run time.)
113    
114    . If, in addition to support for UTF-8 character strings, you want to include
115      support for the \P, \p, and \X sequences that recognize Unicode character
116      properties, you must add --enable-unicode-properties to the "configure"
117      command. This adds about 30K to the size of the library (in the form of a
118      property table); only the basic two-letter properties such as Lu are
119      supported.
120    
121    . You can build PCRE to recognize either CR or LF or the sequence CRLF or any
122      of the Unicode newline sequences as indicating the end of a line. Whatever
123      you specify at build time is the default; the caller of PCRE can change the
124      selection at run time. The default newline indicator is a single LF character
125      (the Unix standard). You can specify the default newline indicator by adding
126      --newline-is-cr or --newline-is-lf or --newline-is-crlf or --newline-is-any
127      to the "configure" command, respectively.
128    
129    . When called via the POSIX interface, PCRE uses malloc() to get additional
130      storage for processing capturing parentheses if there are more than 10 of
131      them. You can increase this threshold by setting, for example,
132    
133      --with-posix-malloc-threshold=20
134    
135      on the "configure" command.
136    
137    . PCRE has a counter that can be set to limit the amount of resources it uses.
138      If the limit is exceeded during a match, the match fails. The default is ten
139      million. You can change the default by setting, for example,
140    
141      --with-match-limit=500000
142    
143      on the "configure" command. This is just the default; individual calls to
144      pcre_exec() can supply their own value. There is discussion on the pcreapi
145      man page.
146    
147    . There is a separate counter that limits the depth of recursive function calls
148      during a matching process. This also has a default of ten million, which is
149      essentially "unlimited". You can change the default by setting, for example,
150    
151      --with-match-limit-recursion=500000
152    
153      Recursive function calls use up the runtime stack; running out of stack can
154      cause programs to crash in strange ways. There is a discussion about stack
155      sizes in the pcrestack man page.
156    
157    . The default maximum compiled pattern size is around 64K. You can increase
158      this by adding --with-link-size=3 to the "configure" command. You can
159      increase it even more by setting --with-link-size=4, but this is unlikely
160      ever to be necessary. If you build PCRE with an increased link size, test 2
161      (and 5 if you are using UTF-8) will fail. Part of the output of these tests
162      is a representation of the compiled pattern, and this changes with the link
163      size.
164    
165    . You can build PCRE so that its internal match() function that is called from
166      pcre_exec() does not call itself recursively. Instead, it uses blocks of data
167      from the heap via special functions pcre_stack_malloc() and pcre_stack_free()
168      to save data that would otherwise be saved on the stack. To build PCRE like
169      this, use
170    
171      --disable-stack-for-recursion
172    
173      on the "configure" command. PCRE runs more slowly in this mode, but it may be
174      necessary in environments with limited stack sizes. This applies only to the
175      pcre_exec() function; it does not apply to pcre_dfa_exec(), which does not
176      use deeply nested recursion.
177    
178    The "configure" script builds eight files for the basic C library:
179    
180    . Makefile is the makefile that builds the library
181    . config.h contains build-time configuration options for the library
182    . pcre-config is a script that shows the settings of "configure" options
183    . libpcre.pc is data for the pkg-config command
184    . libtool is a script that builds shared and/or static libraries
185    . RunTest is a script for running tests on the library
186    . RunGrepTest is a script for running tests on the pcregrep command
187    
188    In addition, if a C++ compiler is found, the following are also built:
189    
190    . pcrecpp.h is the header file for programs that call PCRE via the C++ wrapper
191    . pcre_stringpiece.h is the header for the C++ "stringpiece" functions
192    
193    The "configure" script also creates config.status, which is an executable
194    script that can be run to recreate the configuration, and config.log, which
195    contains compiler output from tests that "configure" runs.
196    
197    ChangeLog         log of changes to the code  Once "configure" has run, you can run "make". It builds two libraries, called
198    Makefile          for building PCRE  libpcre and libpcreposix, a test program called pcretest, and the pcregrep
199    Performance       notes on performance  command. If a C++ compiler was found on your system, it also builds the C++
200    README            this file  wrapper library, which is called libpcrecpp, and some test programs called
201    Tech.Notes        notes on the encoding  pcrecpp_unittest, pcre_scanner_unittest, and pcre_stringpiece_unittest.
202    pcre.3            man page for the functions  
203    pcreposix.3       man page for the POSIX wrapper API  The command "make test" runs all the appropriate tests. Details of the PCRE
204    maketables.c      auxiliary program for building chartables.c  tests are given in a separate section of this document, below.
205    study.c           ) source of  
206    pcre.c            )   the functions  You can use "make install" to copy the libraries, the public header files
207    pcreposix.c       )  pcre.h, pcreposix.h, pcrecpp.h, and pcre_stringpiece.h (the last two only if
208    pcre.h            header for the external API  the C++ wrapper was built), and the man pages to appropriate live directories
209    pcreposix.h       header for the external POSIX wrapper API  on your system, in the normal way.
210    internal.h        header for internal use  
211    pcretest.c        test program  If you want to remove PCRE from your system, you can run "make uninstall".
212    pgrep.1           man page for pgrep  This removes all the files that "make install" installed. However, it does not
213    pgrep.c           source of a grep utility that uses PCRE  remove any directories, because these are often shared with other programs.
214    perltest          Perl test program  
215    testinput         test data, compatible with Perl  
216    testinput2        test data for error messages and non-Perl things  Retrieving configuration information on Unix-like systems
217    testoutput        test results corresponding to testinput  ---------------------------------------------------------
218    testoutput2       test results corresponding to testinput2  
219    Running "make install" also installs the command pcre-config, which can be used
220  To build PCRE, edit Makefile for your system (it is a fairly simple make file)  to recall information about the PCRE configuration and installation. For
221  and then run it. It builds a two libraries called libpcre.a and libpcreposix.a,  example:
222  a test program called pcretest, and the pgrep command.  
223      pcre-config --version
224  To test PCRE, run pcretest on the file testinput, and compare the output with  
225  the contents of testoutput. There should be no differences. For example:  prints the version number, and
226    
227    pcretest testinput some.file    pcre-config --libs
228    diff some.file testoutput  
229    outputs information about where the library is installed. This command can be
230  Do the same with testinput2, comparing the output with testoutput2, but this  included in makefiles for programs that use PCRE, saving the programmer from
231  time using the -i flag for pcretest, i.e.  having to remember too many details.
232    
233    pcretest -i testinput2 some.file  The pkg-config command is another system for saving and retrieving information
234    diff some.file testoutput2  about installed libraries. Instead of separate commands for each library, a
235    single command is used. For example:
236  The make target "runtest" runs both these tests, using the file "testtry" to  
237  store the intermediate output, deleting it at the end if all goes well.    pkg-config --cflags pcre
238    
239  There are two sets of tests because the first set can also be fed directly into  The data is held in *.pc files that are installed in a directory called
240  the perltest program to check that Perl gives the same results. The second set  pkgconfig.
241  of tests check pcre_info(), pcre_study(), error detection and run-time flags  
242  that are specific to PCRE, as well as the POSIX wrapper API.  
243    Shared libraries on Unix-like systems
244  To install PCRE, copy libpcre.a to any suitable library directory (e.g.  -------------------------------------
245  /usr/local/lib), pcre.h to any suitable include directory (e.g.  
246  /usr/local/include), and pcre.3 to any suitable man directory (e.g.  The default distribution builds PCRE as shared libraries and static libraries,
247  /usr/local/man/man3).  as long as the operating system supports shared libraries. Shared library
248    support relies on the "libtool" script which is built as part of the
249  To install the pgrep command, copy it to any suitable binary directory, (e.g.  "configure" process.
250  /usr/local/bin) and pgrep.1 to any suitable man directory (e.g.  
251  /usr/local/man/man1).  The libtool script is used to compile and link both shared and static
252    libraries. They are placed in a subdirectory called .libs when they are newly
253  PCRE has its own native API, but a set of "wrapper" functions that are based on  built. The programs pcretest and pcregrep are built to use these uninstalled
254  the POSIX API are also supplied in the library libpcreposix.a. Note that this  libraries (by means of wrapper scripts in the case of shared libraries). When
255  just provides a POSIX calling interface to PCRE: the regular expressions  you use "make install" to install shared libraries, pcregrep and pcretest are
256  themselves still follow Perl syntax and semantics. The header file  automatically re-built to use the newly installed shared libraries before being
257  for the POSIX-style functions is called pcreposix.h. The official POSIX name is  installed themselves. However, the versions left in the source directory still
258  regex.h, but I didn't want to risk possible problems with existing files of  use the uninstalled libraries.
259  that name by distributing it that way. To use it with an existing program that  
260  uses the POSIX API it will have to be renamed or pointed at by a link.  To build PCRE using static libraries only you must use --disable-shared when
261    configuring it. For example:
262    
263    ./configure --prefix=/usr/gnu --disable-shared
264    
265    Then run "make" in the usual way. Similarly, you can use --disable-static to
266    build only shared libraries.
267    
268    
269    Cross-compiling on a Unix-like system
270    -------------------------------------
271    
272    You can specify CC and CFLAGS in the normal way to the "configure" command, in
273    order to cross-compile PCRE for some other host. However, during the building
274    process, the dftables.c source file is compiled *and run* on the local host, in
275    order to generate the default character tables (the chartables.c file). It
276    therefore needs to be compiled with the local compiler, not the cross compiler.
277    You can do this by specifying CC_FOR_BUILD (and if necessary CFLAGS_FOR_BUILD;
278    there are also CXX_FOR_BUILD and CXXFLAGS_FOR_BUILD for the C++ wrapper)
279    when calling the "configure" command. If they are not specified, they default
280    to the values of CC and CFLAGS.
281    
282    
283    Using HP's ANSI C++ compiler (aCC)
284    ----------------------------------
285    
286    Unless C++ support is disabled by specifying the "--disable-cpp" option of the
287    "configure" script, you *must* include the "-AA" option in the CXXFLAGS
288    environment variable in order for the C++ components to compile correctly.
289    
290    Also, note that the aCC compiler on PA-RISC platforms may have a defect whereby
291    needed libraries fail to get included when specifying the "-AA" compiler
292    option. If you experience unresolved symbols when linking the C++ programs,
293    use the workaround of specifying the following environment variable prior to
294    running the "configure" script:
295    
296      CXXLDFLAGS="-lstd_v2 -lCsup_v2"
297    
298    
299    Building on non-Unix systems
300    ----------------------------
301    
302    For a non-Unix system, read the comments in the file NON-UNIX-USE, though if
303    the system supports the use of "configure" and "make" you may be able to build
304    PCRE in the same way as for Unix systems.
305    
306    PCRE has been compiled on Windows systems and on Macintoshes, but I don't know
307    the details because I don't use those systems. It should be straightforward to
308    build PCRE on any system that has a Standard C compiler and library, because it
309    uses only Standard C functions.
310    
311    
312    Testing PCRE
313    ------------
314    
315    To test PCRE on a Unix system, run the RunTest script that is created by the
316    configuring process. There is also a script called RunGrepTest that tests the
317    options of the pcregrep command. If the C++ wrapper library is build, three
318    test programs called pcrecpp_unittest, pcre_scanner_unittest, and
319    pcre_stringpiece_unittest are provided.
320    
321    Both the scripts and all the program tests are run if you obey "make runtest",
322    "make check", or "make test". For other systems, see the instructions in
323    NON-UNIX-USE.
324    
325    The RunTest script runs the pcretest test program (which is documented in its
326    own man page) on each of the testinput files (in the testdata directory) in
327    turn, and compares the output with the contents of the corresponding testoutput
328    files. A file called testtry is used to hold the main output from pcretest
329    (testsavedregex is also used as a working file). To run pcretest on just one of
330    the test files, give its number as an argument to RunTest, for example:
331    
332      RunTest 2
333    
334    The first test file can also be fed directly into the perltest script to check
335    that Perl gives the same results. The only difference you should see is in the
336    first few lines, where the Perl version is given instead of the PCRE version.
337    
338    The second set of tests check pcre_fullinfo(), pcre_info(), pcre_study(),
339    pcre_copy_substring(), pcre_get_substring(), pcre_get_substring_list(), error
340    detection, and run-time flags that are specific to PCRE, as well as the POSIX
341    wrapper API. It also uses the debugging flag to check some of the internals of
342    pcre_compile().
343    
344    If you build PCRE with a locale setting that is not the standard C locale, the
345    character tables may be different (see next paragraph). In some cases, this may
346    cause failures in the second set of tests. For example, in a locale where the
347    isprint() function yields TRUE for characters in the range 128-255, the use of
348    [:isascii:] inside a character class defines a different set of characters, and
349    this shows up in this test as a difference in the compiled code, which is being
350    listed for checking. Where the comparison test output contains [\x00-\x7f] the
351    test will contain [\x00-\xff], and similarly in some other cases. This is not a
352    bug in PCRE.
353    
354    The third set of tests checks pcre_maketables(), the facility for building a
355    set of character tables for a specific locale and using them instead of the
356    default tables. The tests make use of the "fr_FR" (French) locale. Before
357    running the test, the script checks for the presence of this locale by running
358    the "locale" command. If that command fails, or if it doesn't include "fr_FR"
359    in the list of available locales, the third test cannot be run, and a comment
360    is output to say why. If running this test produces instances of the error
361    
362      ** Failed to set locale "fr_FR"
363    
364    in the comparison output, it means that locale is not available on your system,
365    despite being listed by "locale". This does not mean that PCRE is broken.
366    
367    The fourth test checks the UTF-8 support. It is not run automatically unless
368    PCRE is built with UTF-8 support. To do this you must set --enable-utf8 when
369    running "configure". This file can be also fed directly to the perltest script,
370    provided you are running Perl 5.8 or higher. (For Perl 5.6, a small patch,
371    commented in the script, can be be used.)
372    
373    The fifth test checks error handling with UTF-8 encoding, and internal UTF-8
374    features of PCRE that are not relevant to Perl.
375    
376    The sixth and test checks the support for Unicode character properties. It it
377    not run automatically unless PCRE is built with Unicode property support. To to
378    this you must set --enable-unicode-properties when running "configure".
379    
380    The seventh, eighth, and ninth tests check the pcre_dfa_exec() alternative
381    matching function, in non-UTF-8 mode, UTF-8 mode, and UTF-8 mode with Unicode
382    property support, respectively. The eighth and ninth tests are not run
383    automatically unless PCRE is build with the relevant support.
384    
385    
386  Character tables  Character tables
387  ----------------  ----------------
388    
389  PCRE uses four tables for manipulating and identifying characters. These are  PCRE uses four tables for manipulating and identifying characters whose values
390  compiled from a source file called chartables.c. This is not supplied in  are less than 256. The final argument of the pcre_compile() function is a
391  the distribution, but is built by the program maketables (compiled from  pointer to a block of memory containing the concatenated tables. A call to
392  maketables.c), which uses the ANSI C character handling functions such as  pcre_maketables() can be used to generate a set of tables in the current
393  isalnum(), isalpha(), isupper(), islower(), etc. to build the table sources.  locale. If the final argument for pcre_compile() is passed as NULL, a set of
394  This means that the default C locale set in your system may affect the contents  default tables that is built into the binary is used.
395  of the tables. You can change the tables by editing chartables.c and then  
396  re-building PCRE. If you do this, you should probably also edit Makefile to  The source file called chartables.c contains the default set of tables. This is
397  ensure that the file doesn't ever get re-generated.  not supplied in the distribution, but is built by the program dftables
398    (compiled from dftables.c), which uses the ANSI C character handling functions
399  The first two tables pcre_lcc[] and pcre_fcc[] provide lower casing and a  such as isalnum(), isalpha(), isupper(), islower(), etc. to build the table
400  case flipping functions, respectively. The pcre_cbits[] table consists of four  sources. This means that the default C locale which is set for your system will
401  32-byte bit maps which identify digits, letters, "word" characters, and white  control the contents of these default tables. You can change the default tables
402  space, respectively. These are used when building 32-byte bit maps that  by editing chartables.c and then re-building PCRE. If you do this, you should
403  represent character classes.  probably also edit Makefile to ensure that the file doesn't ever get
404    re-generated.
405    
406    The first two 256-byte tables provide lower casing and case flipping functions,
407    respectively. The next table consists of three 32-byte bit maps which identify
408    digits, "word" characters, and white space, respectively. These are used when
409    building 32-byte bit maps that represent character classes.
410    
411  The pcre_ctypes[] table has bits indicating various character types, as  The final 256-byte table has bits indicating various character types, as
412  follows:  follows:
413    
414      1   white space character      1   white space character
# Line 102  You should not alter the set of characte Line 422  You should not alter the set of characte
422  will cause PCRE to malfunction.  will cause PCRE to malfunction.
423    
424    
425  The pcretest program  Manifest
426  --------------------  --------
427    
428    The distribution should contain the following files:
429    
430  This program is intended for testing PCRE, but it can also be used for  (A) The actual source files of the PCRE library functions and their
431  experimenting with regular expressions.      headers:
432    
433  If it is given two filename arguments, it reads from the first and writes to    dftables.c            auxiliary program for building chartables.c
 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.  
   
 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  
 set. The regular expressions are given enclosed in any non-alphameric  
 delimiters, for example  
   
   /(a|bc)x+yz/  
   
 and may be followed by i, m, s, or x to set the PCRE_CASELESS, PCRE_MULTILINE,  
 PCRE_DOTALL, or PCRE_EXTENDED options, respectively. These options have the  
 same effect as they do in Perl.  
   
 There are also some upper case options that do not match Perl options: /A, /E,  
 and /X set PCRE_ANCHORED, PCRE_DOLLAR_ENDONLY, and PCRE_EXTRA respectively.  
 The /D option is a PCRE debugging feature. It causes the internal form of  
 compiled regular expressions to be output after compilation. The /S option  
 causes pcre_study() to be called after the expression has been compiled, and  
 the results used when the expression is matched. If /I is present as well as  
 /S, then pcre_study() is called with the PCRE_CASELESS option.  
   
 Finally, the /P option causes pcretest to call PCRE via the POSIX wrapper API  
 rather than its native API. When this is done, all other options except /i and  
 /m 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.  
   
 A regular expression can extend over several lines of input; the newlines are  
 included in it. See the testinput file for many examples.  
   
 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()  
   \E     pass the PCRE_DOLLAR_ENDONLY option to pcre_exec()  
   \I     pass the PCRE_CASELESS option to pcre_exec()  
   \M     pass the PCRE_MULTILINE option to pcre_exec()  
   \S     pass the PCRE_DOTALL 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 identified 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  
   Testing Perl-Compatible Regular Expressions  
   PCRE version 0.90 08-Sep-1997  
   
       re> /^abc(\d+)/  
     data> abc123  
    0: abc123  
    1: 123  
     data> xyz  
   No match  
   
 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 (for "information") is given to pcretest, it calls pcre_info()  
 after compiling an expression, and outputs the information it gets back. If the  
 pattern is studied, the results of that are also output.  
   
 If the option -s is given to pcretest, it outputs the size of each compiled  
 pattern after it has been compiled.  
   
 If the -t option is given, each compile, study, and match is run 2000 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  
 2000 times and the timing will be distorted.  
   
   
   
 The perltest program  
 --------------------  
   
 The perltest program tests Perl's regular expressions; it has the same  
 specification as pcretest, and so can be given identical input, except that  
 input patterns can be followed only by Perl's lower case options.  
   
 The data lines are processed as Perl strings, so if they contain $ or @  
 characters, these have to be escaped. For this reason, all such characters in  
 the testinput file are escaped so that it can be used for perltest as well as  
 for pcretest, and the special upper case options such as /A that pcretest  
 recognizes are not used in this file. The output should be identical, apart  
 from the initial identifying banner.  
   
 The testinput2 file is not suitable for feeding to Perltest, since it does  
 make use of the special upper case options and escapes that pcretest uses to  
 test additional features of PCRE.  
434    
435  Philip Hazel <ph10@cam.ac.uk>    pcreposix.c           )
436  October 1997    pcre_compile.c        )
437      pcre_config.c         )
438      pcre_dfa_exec.c       )
439      pcre_exec.c           )
440      pcre_fullinfo.c       )
441      pcre_get.c            ) sources for the functions in the library,
442      pcre_globals.c        )   and some internal functions that they use
443      pcre_info.c           )
444      pcre_maketables.c     )
445      pcre_newline.c        )
446      pcre_ord2utf8.c       )
447      pcre_refcount.c       )
448      pcre_study.c          )
449      pcre_tables.c         )
450      pcre_try_flipped.c    )
451      pcre_ucp_searchfuncs.c)
452      pcre_valid_utf8.c     )
453      pcre_version.c        )
454      pcre_xclass.c         )
455      ucptable.c            )
456    
457      pcre_printint.src     ) debugging function that is #included in pcretest, and
458                            )   can also be #included in pcre_compile()
459    
460      pcre.h                the public PCRE header file
461      pcreposix.h           header for the external POSIX wrapper API
462      pcre_internal.h       header for internal use
463      ucp.h                 ) headers concerned with
464      ucpinternal.h         )   Unicode property handling
465      config.in             template for config.h, which is built by configure
466    
467      pcrecpp.h             the header file for the C++ wrapper
468      pcrecpparg.h.in       "source" for another C++ header file
469      pcrecpp.cc            )
470      pcre_scanner.cc       ) source for the C++ wrapper library
471    
472      pcre_stringpiece.h.in "source" for pcre_stringpiece.h, the header for the
473                              C++ stringpiece functions
474      pcre_stringpiece.cc   source for the C++ stringpiece functions
475    
476    (B) Auxiliary files:
477    
478      AUTHORS               information about the author of PCRE
479      ChangeLog             log of changes to the code
480      INSTALL               generic installation instructions
481      LICENCE               conditions for the use of PCRE
482      COPYING               the same, using GNU's standard name
483      Makefile.in           template for Unix Makefile, which is built by configure
484      NEWS                  important changes in this release
485      NON-UNIX-USE          notes on building PCRE on non-Unix systems
486      README                this file
487      RunTest.in            template for a Unix shell script for running tests
488      RunGrepTest.in        template for a Unix shell script for pcregrep tests
489      config.guess          ) files used by libtool,
490      config.sub            )   used only when building a shared library
491      config.h.in           "source" for the config.h header file
492      configure             a configuring shell script (built by autoconf)
493      configure.ac          the autoconf input used to build configure
494      doc/Tech.Notes        notes on the encoding
495      doc/*.3               man page sources for the PCRE functions
496      doc/*.1               man page sources for pcregrep and pcretest
497      doc/html/*            HTML documentation
498      doc/pcre.txt          plain text version of the man pages
499      doc/pcretest.txt      plain text documentation of test program
500      doc/perltest.txt      plain text documentation of Perl test program
501      install-sh            a shell script for installing files
502      libpcre.pc.in         "source" for libpcre.pc for pkg-config
503      ltmain.sh             file used to build a libtool script
504      mkinstalldirs         script for making install directories
505      pcretest.c            comprehensive test program
506      pcredemo.c            simple demonstration of coding calls to PCRE
507      perltest              Perl test program
508      pcregrep.c            source of a grep utility that uses PCRE
509      pcre-config.in        source of script which retains PCRE information
510      pcrecpp_unittest.c           )
511      pcre_scanner_unittest.c      ) test programs for the C++ wrapper
512      pcre_stringpiece_unittest.c  )
513      testdata/testinput*   test data for main library tests
514      testdata/testoutput*  expected test results
515      testdata/grep*        input and output for pcregrep tests
516    
517    (C) Auxiliary files for Win32 DLL
518    
519      libpcre.def
520      libpcreposix.def
521    
522    (D) Auxiliary file for VPASCAL
523    
524      makevp.bat
525    
526    Philip Hazel
527    Email local part: ph10
528    Email domain: cam.ac.uk
529    November 2006

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