Useful Link : Learn regular expression


 
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Old 05-10-2011
Useful Link : Learn regular expression

Hi All,

recently i came across this site txt2re site is good for learning how to write regular expression.

P.S : Mods I was not sure where to post this hence i posted it here. You can move to proper section.
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re_comp(3C)						   Standard C Library Functions 					       re_comp(3C)

NAME
re_comp, re_exec - compile and execute regular expressions SYNOPSIS
#include <re_comp.h> char *re_comp(const char *string); int re_exec(const char *string); DESCRIPTION
The re_comp() function converts a regular expression string (RE) into an internal form suitable for pattern matching. The re_exec() func- tion compares the string pointed to by the string argument with the last regular expression passed to re_comp(). If re_comp() is called with a null pointer argument, the current regular expression remains unchanged. Strings passed to both re_comp() and re_exec() must be terminated by a null byte, and may include NEWLINE characters. The re_comp() and re_exec() functions support simple regular expressions, which are defined on the regexp(5) manual page. The regular expressions of the form {m}, {m,}, or {m,n} are not supported. RETURN VALUES
The re_comp() function returns a null pointer when the string pointed to by the string argument is successfully converted. Otherwise, a pointer to one of the following error message strings is returned: No previous regular expression Regular expression too long unmatched ( missing ] too many () pairs unmatched ) Upon successful completion, re_exec() returns 1 if string matches the last compiled regular expression. Otherwise, re_exec() returns 0 if string fails to match the last compiled regular expression, and -1 if the compiled regular expression is invalid (indicating an internal error). ERRORS
No errors are defined. USAGE
For portability to implementations conforming to X/Open standards prior to SUS, regcomp(3C) and regexec(3C) are preferred to these func- tions. See standards(5). SEE ALSO
grep(1), regcmp(1), regcmp(3C), regcomp(3C), regexec(3C), regexpr(3GEN), regexp(5), standards(5) SunOS 5.11 26 Feb 1997 re_comp(3C)