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Top Forums Shell Programming and Scripting Question on regex with * and . Post 302437921 by clx on Friday 16th of July 2010 03:35:07 PM
Old 07-16-2010
Quote:
Originally Posted by mirage
'.' matches "one or more of previous characters"
"." (dot) specifies "any single character"
"+" (plus) specifies "one or more of previous"

---------- Post updated at 01:04 AM ---------- Previous update was at 12:59 AM ----------

Quote:
Originally Posted by mirage
I should be reading it as:
"Match characters
^ - starting with
[0123456789] - one of the digits from 0 thro' 9 and
*$ - zero (none) or more of digits from 0 thro' 9 at the end. "

Thus it matches 3, 33, 34, 345 etc.

You should read as:

"Match characters
^ - starting with
[0123456789]* - zero or more digits from 0 thro' 9 and
$ - end."

---------- Post updated at 01:05 AM ---------- Previous update was at 01:04 AM ----------

Quote:
Originally Posted by mirage
I should be reading it as:
"Match characters
^ - starting with
[0123456789] - one of the digits from 0 thro' 9 and
*$ - zero or more of digits from 0 thro' 9 at the end. "

Thus it matches 3, 33, 34, 345 etc.

You should read as:

"Match characters
^ - starting with
[0123456789]* - zero (none) or more digits from 0 thro' 9 and
$ - end."
 

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RE_COMP(3)						     Linux Programmer's Manual							RE_COMP(3)

NAME
re_comp, re_exec - BSD regex functions SYNOPSIS
#define _REGEX_RE_COMP #include <sys/types.h> #include <regex.h> char *re_comp(char *regex); int re_exec(char *string); DESCRIPTION
re_comp() is used to compile the null-terminated regular expression pointed to by regex. The compiled pattern occupies a static area, the pattern buffer, which is overwritten by subsequent use of re_comp(). If regex is NULL, no operation is performed and the pattern buffer's contents are not altered. re_exec() is used to assess whether the null-terminated string pointed to by string matches the previously compiled regex. RETURN VALUE
re_comp() returns NULL on successful compilation of regex otherwise it returns a pointer to an appropriate error message. re_exec() returns 1 for a successful match, zero for failure. CONFORMING TO
4.3BSD. NOTES
These functions are obsolete; the functions documented in regcomp(3) should be used instead. SEE ALSO
regcomp(3), regex(7), GNU regex manual COLOPHON
This page is part of release 3.25 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. GNU
1995-07-14 RE_COMP(3)
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