re_comp()

Compile a regular expression

Synopsis:

#include <unix.h>

char *re_comp( char *s );

Arguments:

s

A string that contains the regular expression that you want to compile. This string must end with a null byte and may include newline characters. If this argument is NULL, the current regular expression remains unchanged.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

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This function is in libc.a, but not in libc.so (in order to save space).

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Description:

The re_comp() function converts a regular expression string (RE) into an internal form suitable for pattern matching. Use this function with re_exec().

The re_comp() and re_exec() functions support simple regular expressions. The regular expressions of the form \{m\}, \{m,\}, or \{m,n\} aren't supported.

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For better portability, use regcomp(), regerror(), and regexec() instead of these functions.

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Returns:

NULL if the string pointed to by s was 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 \)

Classification:

Legacy Unix

See also:

re_exec(), regcomp(), regerror(), regexec()

grep in the Utilities Reference