STRING(3)

NAME
strcat, strncat, strcmp, strncmp, strcpy, strncpy, strlen, index, rindex, strtok - string operations

SYNOPSIS
#include <strings.h>

char *strcat(s1, s2)
char *s1, *s2;

char *strncat(s1, s2, n)
char *s1, *s2;

strcmp(s1, s2)
char *s1, *s2;

strncmp(s1, s2, n)
char *s1, *s2;

char *strcpy(s1, s2)
char *s1, *s2;

char *strncpy(s1, s2, n)
char *s1, *s2;

strlen(s)
char *s;

char *index(s, c)
char *s, c;

char *rindex(s, c)
char *s, c;

char *strtok(s1, s2)
char *s1, *s2;

DESCRIPTION
These functions operate on null-terminated strings. They do not check for overflow of any receiving string.

Strcat appends a copy of string s2 to the end of string s1. Strncat copies at most n characters. Both return a pointer to the null-terminated result.

Strcmp compares its arguments and returns an integer greater than, equal to, or less than 0, according as s1 is lexicographically greater than, equal to, or less than s2. Strncmp makes the same comparison but looks at at most n characters.

Strcpy copies string s2 to s1, stopping after the null character has been moved. Strncpy copies exactly n characters, truncating or null-padding s2; the target may not be null-terminated if the length of s2 is n or more. Both return s1.

Strlen returns the number of non-null characters in s.

Index (rindex) returns a pointer to the first (last) occurrence of character c in string s, or zero if c does not occur in the string.

Strtok considers the string s1 to consist of a sequence of zero or more text tokens separated by spans of one or more characters from the separator string s2. The first call (with pointer s1 specified) returns a pointer to the first character of the first token, and will have written a NULL character into s1 immediately following the returned token. The function keeps track of its position in the string between separate calls, so that subsequent calls (which must be made with the first argument a NULL pointer) will work through the string s1 immediately following that token. In this way subsequent calls will work through the string s1 until no tokens remain. The separator string s2 may be different from call to call. When no token remains in s1, a NULL pointer is returned.