diff options
Diffstat (limited to 'lib/libc')
| -rw-r--r-- | lib/libc/string/strcpy.3 | 38 |
1 files changed, 35 insertions, 3 deletions
diff --git a/lib/libc/string/strcpy.3 b/lib/libc/string/strcpy.3 index ff74d58f8fa..0e4804200fa 100644 --- a/lib/libc/string/strcpy.3 +++ b/lib/libc/string/strcpy.3 @@ -33,7 +33,7 @@ .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" -.\" $OpenBSD: strcpy.3,v 1.3 1998/11/28 14:51:34 espie Exp $ +.\" $OpenBSD: strcpy.3,v 1.4 1999/03/05 23:16:05 millert Exp $ .\" .Dd June 29, 1991 .Dt STRCPY 3 @@ -96,16 +96,48 @@ The following sets to .Dq Li abc\e0\e0\e0 : .Bd -literal -offset indent -(void)strncpy(chararray, "abc", 6). +(void)strncpy(chararray, "abc", 6); .Ed .Pp The following sets .Dq Li chararray to -.Dq Li abcdef : +.Dq Li abcdef +and does +.Em not +NUL-terminate chararray because the source string is >= the length parameter. +.Fn strncpy +.Em only +NUL-terminates the destination string when then length of the source +string is less than the length parameter. .Bd -literal -offset indent (void)strncpy(chararray, "abcdefgh", 6); .Ed +.Pp +The following copies as many characters from +.Dq Li input +to +.Dq Li buf +as will fit and NUL-terminates the result. Because +.Fn strncpy +does +.Em not +guarantee to NUL-terminate the string itself, we must do this by hand. +.Bd -literal -offset indent +char buf[BUFSIZ]; + +(void)strncpy(buf, input, sizeof(buf) - 1); +buf[sizeof(buf) - 1] = '\\0'; +.Ed +.Pp +Note that +.Xr strlcpy 3 +is a better choice for this kind of operation. The equivalent using +.Xr strlcpy 3 +is simply: +.Bd -literal -offset indent +(void)strncpy(buf, input, sizeof(buf)); +.Ed .Sh SEE ALSO .Xr bcopy 3 , .Xr memccpy 3 , |