STRSTR(3) | Library Functions Manual | STRSTR(3)

# NAME

`strstr`, `strcasestr` — locate a substring in a string

# SYNOPSIS

`#include <string.h>`

char *
`strstr`(const char *big, const char *little);

char *
`strcasestr`(const char *big, const char *little);

# DESCRIPTION

The `strstr`() function locates the first occurrence of the NUL-terminated string little in the NUL-terminated string big.

The `strcasestr`() function is similar to `strstr`() but ignores the case of both strings.

# RETURN VALUES

If little is an empty string, big is returned; if little occurs nowhere in big, `NULL` is returned; otherwise a pointer to the first character of the first occurrence of little is returned.

# SEE ALSO

memchr(3), memmem(3), strchr(3), strcspn(3), strpbrk(3), strrchr(3), strsep(3), strspn(3), strtok(3), wcsstr(3)

# STANDARDS

The `strstr`() function conforms to ANSI X3.159-1989 (“ANSI C89”).

# HISTORY

The `strstr`() function first appeared in 4.3BSD-Reno. The `strcasestr`() function appeared in glibc 2.1, was reimplemented for FreeBSD 4.5 and ported to OpenBSD 3.8.

May 11, 2016 | Debian