June 9, 1993 STRCASECMP 3

### NAME

strcasecmp, strncasecmp - compare strings, ignoring case

### LIBRARY

Standard C Library (libc, -lc)

### SYNOPSIS

```int` strcasecmp(```const char *s1``, const char *s2`)
```int` strncasecmp(```const char *s1``, const char *s2``, size_t len`)

### DESCRIPTION

The strcasecmp(``) and strncasecmp(``) functions compare the nul-terminated strings ```s1` and ```s2` and return an integer greater than, equal to, or less than 0, according to whether ```s1` is lexicographically greater than, equal to, or less than ```s2` after translation of each corresponding character to lower-case. The strings themselves are not modified. The comparison is done using unsigned characters, so that ````\200`' is greater than `\0'.

The strncasecmp(``) compares at most ```len` characters.

### SEE ALSO

bcmp(3), memcmp(3), strcmp(3), strcoll(3), strxfrm(3)

### HISTORY

The strcasecmp(``) and strncasecmp(``) functions first appeared in 4.4BSD.

### NOTES

If ```len` is zero strncasecmp(``) returns always 0.