Useful string functions source code

This snippet submitted by yzb3 on 2012-03-14. It has been viewed 34942 times.
Rating of 6.0 with 217 votes

#include <string.h>
#include <stdlib.h>

void remchars(char *str, char c);
void remcnks(char *str, char *cnk);
void replchars(char *str, char c1, char c2);
void replcnks(char *str, char *cnk1, char *cnk2);
void reverse(char *str);

//remove specified characters from a string
void remchars(char *str, char c)
{
	char *pos;
	while(pos = strchr(str,c))
		memmove(pos, pos + 1, strlen(pos));
}

//remove specified chunks from a string
void remcnks(char *str, char *cnk)
{
	char *pos;
	int clen = strlen(cnk);
	while(pos = strstr(str, cnk))
		memmove(pos, pos + clen, strlen(pos) - clen + 1);
}

//replace specified characters in a string
void replchars(char *str, char c1, char c2)
{
	char *pos;
	while(pos = strchr(str, c1))
		*pos = c2;
}

//replace specified chunks in a string (size-independent, just remember about memory)
void replcnks(char *str, char *cnk1, char *cnk2)
{
	char *pos;
	int clen1 = strlen(cnk1), clen2 = strlen(cnk2);
	while(pos = strstr(str, cnk1))
	{
		memmove(pos + clen2, pos + clen1, strlen(pos) - clen1 + 1);
		memcpy(pos, cnk2, clen2);
	}
}

//reverse a string
void reverse(char *str)
{
	int i;
	int len = strlen(str) - 1;
	int mid = (len % 2) ? (len / 2) : ((len + 1) / 2);
	for(i = 0; i <= mid; ++i)
	{
		char buf = str[i];
		str[i] = str[len - i];
		str[len - i] = buf;
	}
}

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