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| author | Jacob McDonnell <jacob@jacobmcdonnell.com> | 2026-04-25 19:54:44 -0400 |
|---|---|---|
| committer | Jacob McDonnell <jacob@jacobmcdonnell.com> | 2026-04-25 19:54:44 -0400 |
| commit | a9157ce950dfe2fc30795d43b9d79b9d1bffc48b (patch) | |
| tree | 9df484304b560466d145e662c1c254ff0e9ae0ba /static/openbsd/man3/stpcpy.3 | |
| parent | 160aa82b2d39c46ad33723d7d909cb4972efbb03 (diff) | |
docs: Added All OpenBSD Manuals
Diffstat (limited to 'static/openbsd/man3/stpcpy.3')
| -rw-r--r-- | static/openbsd/man3/stpcpy.3 | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/static/openbsd/man3/stpcpy.3 b/static/openbsd/man3/stpcpy.3 new file mode 100644 index 00000000..973eebec --- /dev/null +++ b/static/openbsd/man3/stpcpy.3 @@ -0,0 +1,184 @@ +.\" $OpenBSD: stpcpy.3,v 1.6 2014/02/23 23:09:34 schwarze Exp $ +.\" +.\" Copyright (c) 1990, 1991 The Regents of the University of California. +.\" All rights reserved. +.\" +.\" This code is derived from software contributed to Berkeley by +.\" Chris Torek and the American National Standards Committee X3, +.\" on Information Processing Systems. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.Dd $Mdocdate: February 23 2014 $ +.Dt STPCPY 3 +.Os +.Sh NAME +.Nm stpcpy , +.Nm stpncpy +.Nd copy strings +.Sh SYNOPSIS +.In string.h +.Ft char * +.Fn stpcpy "char *dst" "const char *src" +.Ft char * +.Fn stpncpy "char *dst" "const char *src" "size_t len" +.Sh DESCRIPTION +The +.Fn stpcpy +and +.Fn stpncpy +functions copy the string +.Fa src +to +.Fa dst +(including the terminating +.Ql \e0 +character). +.Pp +The +.Fn stpncpy +function copies not more than +.Fa len +characters into +.Fa dst , +appending +.Ql \e0 +characters if +.Fa src +is less than +.Fa len +characters long, and +.Em not +terminating +.Fa dst +if the length of +.Fa src +is greater than or equal to +.Fa len . +.Pp +If the +.Fa src +and +.Fa dst +strings overlap, the behavior is undefined. +.Sh RETURN VALUES +The +.Fn stpcpy +function returns a pointer to the terminating +.Ql \e0 +character written into +.Fa dst . +.Pp +The +.Fn stpncpy +function returns a pointer to the first +.Ql \e0 +character written into +.Fa dst , +or to +.Fa &dst[len] +if the length of +.Fa src +is greater than or equal to +.Fa len . +.Sh EXAMPLES +The most common use of +.Fn stpcpy +is to build up a string from multiple elements. +The following example builds up a pathname from +directory and file components using +.Fn stpcpy : +.Bd -literal -offset indent +char *dir, *file, pname[PATH_MAX]; + +\&... + +if (strlen(dir) + strlen("/") + strlen(file) >= sizeof(pname)) + goto toolong; +stpcpy(stpcpy(stpcpy(pname, dir), "/"), file); +.Ed +.Pp +However, the size check required to avoid a buffer overflow is error +prone since the check can become out of sync with the code that +performs the copy. +.Pp +One might expect that +.Fn stpncpy +could be safely used instead, but it suffers from the same defects as +.Fn strncpy . +The example below using +.Fn stpncpy +is even more prone to error and will not detect when truncation occurs: +.Bd -literal -offset indent +char *dir, *file, pname[PATH_MAX]; +char *p1, *p2; + +\&... + +p1 = stpncpy(pname, dir, sizeof(pname) - 1); +p2 = stpncpy(p1, "/", sizeof(pname) - 1 - (p1 - pname)); +stpncpy(p2, file, sizeof(pname) - 1 - (p2 - pname)); +pname[sizeof(pname) - 1] = '\e0'; +.Ed +.Pp +A safer (and simpler) approach is to use +.Fn snprintf : +.Bd -literal -offset indent +char *dir, *file, pname[PATH_MAX]; +int len; + +\&... + +len = snprintf(pname, sizeof(pname), "%s/%s", dir, file); +if (len >= sizeof(pname)) + goto toolong; +.Ed +.Pp +In most cases, it is better to use +.Fn snprintf , +.Fn strlcpy , +or +.Fn strlcat . +.Sh SEE ALSO +.Xr snprintf 3 , +.Xr strcpy 3 , +.Xr strlcpy 3 , +.Xr strncpy 3 +.Sh STANDARDS +The +.Fn stpcpy +and +.Fn stpncpy +functions conform to +.St -p1003.1-2008 . +.Sh HISTORY +The function +.Fn stpcpy +first appeared in the Lattice C AmigaDOS compiler (1986 or earlier). +The function +.Fn stpncpy +first appeared in the GNU C library version 1.07 (1993). +Both functions have been available since +.Ox 5.1 . |
