If you save compiled patterns to a file, you can copy them to a different host and run them there. If the two hosts have different endianness (byte order), -you should run the pcre[16]_pattern_to_host_byte_order() function on the +you should run the pcre[16|32]_pattern_to_host_byte_order() function on the new host before trying to match the pattern. The matching functions return PCRE_ERROR_BADENDIANNESS if they detect a pattern with the wrong endianness.
@@ -46,9 +46,9 @@ restoring a compiled pattern loses any JIT optimizatio-The value returned by pcre[16]_compile() points to a single block of +The value returned by pcre[16|32]_compile() points to a single block of memory that holds the compiled pattern and associated data. You can find the -length of this block in bytes by calling pcre[16]_fullinfo() with an +length of this block in bytes by calling pcre[16|32]_fullinfo() with an argument of PCRE_INFO_SIZE. You can then save the data in any appropriate manner. Here is sample code for the 8-bit library that compiles a pattern and writes it to a file. It assumes that the variable fd refers to a file @@ -87,31 +87,31 @@ If the pattern has been studied, it is also possible t data in a similar way to the compiled pattern itself. However, if the PCRE_STUDY_JIT_COMPILE was used, the just-in-time data that is created cannot be saved because it is too dependent on the current environment. When studying -generates additional information, pcre[16]_study() returns a pointer to a -pcre[16]_extra data block. Its format is defined in the +generates additional information, pcre[16|32]_study() returns a pointer to a +pcre[16|32]_extra data block. Its format is defined in the section on matching a pattern in the pcreapi documentation. The study_data field points to the binary study data, and -this is what you must save (not the pcre[16]_extra block itself). The -length of the study data can be obtained by calling pcre[16]_fullinfo() +this is what you must save (not the pcre[16|32]_extra block itself). The +length of the study data can be obtained by calling pcre[16|32]_fullinfo() with an argument of PCRE_INFO_STUDYSIZE. Remember to check that -pcre[16]_study() did return a non-NULL value before trying to save the +pcre[16|32]_study() did return a non-NULL value before trying to save the study data.
Re-using a precompiled pattern is straightforward. Having reloaded it into main -memory, called pcre[16]_pattern_to_host_byte_order() if necessary, -you pass its pointer to pcre[16]_exec() or pcre[16]_dfa_exec() in +memory, called pcre[16|32]_pattern_to_host_byte_order() if necessary, you +pass its pointer to pcre[16|32]_exec() or pcre[16|32]_dfa_exec() in the usual way.
However, if you passed a pointer to custom character tables when the pattern -was compiled (the tableptr argument of pcre[16]_compile()), you -must now pass a similar pointer to pcre[16]_exec() or -pcre[16]_dfa_exec(), because the value saved with the compiled pattern -will obviously be nonsense. A field in a pcre[16]_extra() block is used +was compiled (the tableptr argument of pcre[16|32]_compile()), you +must now pass a similar pointer to pcre[16|32]_exec() or +pcre[16|32]_dfa_exec(), because the value saved with the compiled pattern +will obviously be nonsense. A field in a pcre[16|32]_extra() block is used to pass this data, as described in the section on matching a pattern in the @@ -119,6 +119,11 @@ in the documentation.
+Warning: The tables that pcre_exec() and pcre_dfa_exec() use +must be the same as those that were used when the pattern was compiled. If this +is not the case, the behaviour is undefined. +
+If you did not provide custom character tables when the pattern was compiled, the pointer in the compiled pattern is NULL, which causes the matching functions to use PCRE's internal tables. Thus, you do not need to take any @@ -126,10 +131,10 @@ special action at run time in this case.
If you saved study data with the compiled pattern, you need to create your own -pcre[16]_extra data block and set the study_data field to point to the -reloaded study data. You must also set the PCRE_EXTRA_STUDY_DATA bit in the -flags field to indicate that study data is present. Then pass the -pcre[16]_extra block to the matching function in the usual way. If the +pcre[16|32]_extra data block and set the study_data field to point +to the reloaded study data. You must also set the PCRE_EXTRA_STUDY_DATA bit in +the flags field to indicate that study data is present. Then pass the +pcre[16|32]_extra block to the matching function in the usual way. If the pattern was studied for just-in-time optimization, that data cannot be saved, and so is lost by a save/restore cycle.
@@ -149,9 +154,9 @@ Cambridge CB2 3QH, England.
-Last updated: 10 January 2012
+Last updated: 12 November 2013
-Copyright © 1997-2012 University of Cambridge.
+Copyright © 1997-2013 University of Cambridge.
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