August 11, 2002 STRSPN 3

### NAME

strspn - span a string

### LIBRARY

Standard C Library (libc, -lc)

### SYNOPSIS

```size_t` strspn(```const char *s``, const char *charset`)

### DESCRIPTION

The strspn(``) function spans the initial part of the nul-terminated string ```s` as long as the characters from ```s` occur in string ```charset`.

### RETURN VALUES

The strspn(``) function returns the number of characters spanned.

### EXAMPLES

The following call to strspn(``) will return 3, since the first three characters of string ```s` are part of string ```charset`:

  `

      char *s = "foobar";
      char *charset = "of";
      size_t span;

      span = strspn(s, charset);

  `

### SEE ALSO

index(3), memchr(3), rindex(3), strchr(3), strcspn(3), strpbrk(3), strrchr(3), strsep(3), strstr(3), strtok(3)

### STANDARDS

The strspn(``) function conforms to ANSI X3.159-1989 (``ANSI C89'') .