#include <strings.h> char *strcat(s, append) char *s, *append; char *strncat(s, append, count) char *s, *append; int count; strcmp(s1, s2) char *s1, *s2; strncmp(s1, s2, count) char *s1, *s2; int count; strcasecmp(s1, s2) char *s1, *s2; strncasecmp(s1, s2, count) char *s1, *s2; int count; char *strcpy(to, from) char *to, *from; char *strncpy(to, from, count) char *to, *from; int count; strlen(s) char *s; char *index(s, c) char *s, c; char *rindex(s, c) char *s, c;
Strcat appends a copy of string append to the end of string s. Strncat copies at most count 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 count characters. Strcasecmp and strncasecmp are identical in function, but are case insensitive. The returned lexicographic difference reflects a conversion to lower-case.
Strcpy copies string from to to, stopping after the null character has been moved. Strncpy copies exactly count characters, appending nulls if from is less than count characters in length; the target may not be null-terminated if the length of from is count or more. Both return to.
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. Setting c to NULL works.