str_replace.h

#ifndef COMMON_H
#define COMMON_H

#include <sys/types.h>

// str_replace(haystack, haystacksize, oldneedle, newneedle) --
//  Search haystack and replace all occurences of oldneedle with newneedle.
//  Resulting haystack contains no more than haystacksize characters (including the '\0').
//  If haystacksize is too small to make the replacements, do not modify haystack at all.
//
// RETURN VALUES
// str_replace() returns haystack on success and NULL on failure. 
// Failure means there was not enough room to replace all occurences of oldneedle.
// Success is returned otherwise, even if no replacement is made.
char *str_replace(char *haystack, size_t haystacksize, const char *oldneedle, const char *newneedle);

#endif