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@(#)strspn.3 8.1 (Berkeley) 6/4/93
$FreeBSD: releng/11.0/lib/libc/string/strspn.3 276006 2014-12-21 12:36:36Z brueffer $

.Dd May 24, 2014 .Dt STRSPN 3 .Os .Sh NAME .Nm strspn , .Nm strcspn .Nd span a string .Sh LIBRARY .Lb libc .Sh SYNOPSIS n string.h .Ft size_t .Fn strspn "const char *s" "const char *charset" .Ft size_t .Fn strcspn "const char *s" "const char *charset" .Sh DESCRIPTION The .Fn strspn function spans the initial part of the null-terminated string .Fa s as long as the characters from .Fa s occur in the null-terminated string .Fa charset . In other words, it computes the string array index of the first character of .Fa s which is not in .Fa charset , else the index of the first null character.

p The .Fn strcspn function spans the initial part of the null-terminated string .Fa s as long as the characters from .Fa s .Sy do not occur in the null-terminated string .Fa charset

o it spans the .Sy complement of .Fa charset

c . In other words, it computes the string array index of the first character of .Fa s which is also in .Fa charset , else the index of the first null character. .Sh RETURN VALUES The .Fn strspn and .Fn strcspn functions return the number of characters spanned. .Sh SEE ALSO .Xr memchr 3 , .Xr strchr 3 , .Xr strpbrk 3 , .Xr strrchr 3 , .Xr strsep 3 , .Xr strstr 3 , .Xr strtok 3 , .Xr wcsspn 3 .Sh STANDARDS The .Fn strspn and .Fn strcspn functions conform to .St -isoC .