strcspn
—
span the complement of a string
Standard C Library (libc, -lc)
#include <string.h>
size_t
strcspn
(const
char *s, const char
*charset);
The strcspn
() function spans the initial part of the
nul-terminated string s as long as the characters from
s do not occur in string charset
(it spans the complement of charset).
The strcspn
() function returns the number of characters
spanned.
The following call to strcspn
() will return 3, since the
first three characters of string s do not occur in
string charset:
char *s = "foobar";
char *charset = "bar";
size_t span;
span = strcspn(s, charset);
The strcspn
() function conforms to ANSI
X3.159-1989 (“ANSI C89”).