diff options
author | wollman <wollman@FreeBSD.org> | 2002-10-28 00:15:43 +0000 |
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committer | wollman <wollman@FreeBSD.org> | 2002-10-28 00:15:43 +0000 |
commit | d47f5a7e94eaddce370ce4688d56fb6f615db5fe (patch) | |
tree | ef8b51b7909ca8da3340038a26cdd405f3576f40 /lib/libc/gen/check_utility_compat.c | |
parent | 092b51aeec7dc966bbc8dcd2ac52a71641bd3a4c (diff) | |
download | FreeBSD-src-d47f5a7e94eaddce370ce4688d56fb6f615db5fe.zip FreeBSD-src-d47f5a7e94eaddce370ce4688d56fb6f615db5fe.tar.gz |
Create a small library function, check_utility_compat(3), to determine
whether a named utility should behave in FreeBSD 4.x-compatible mode
or in a standard mode (default standard). The configuration is done
malloc(3)-style, with either an environment variable or a symlink.
Update expr(1) to use this new interface.
Diffstat (limited to 'lib/libc/gen/check_utility_compat.c')
-rw-r--r-- | lib/libc/gen/check_utility_compat.c | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/lib/libc/gen/check_utility_compat.c b/lib/libc/gen/check_utility_compat.c new file mode 100644 index 0000000..0ccdec1 --- /dev/null +++ b/lib/libc/gen/check_utility_compat.c @@ -0,0 +1,75 @@ +/* + * Copyright 2002 Massachusetts Institute of Technology + * + * Permission to use, copy, modify, and distribute this software and + * its documentation for any purpose and without fee is hereby + * granted, provided that both the above copyright notice and this + * permission notice appear in all copies, that both the above + * copyright notice and this permission notice appear in all + * supporting documentation, and that the name of M.I.T. not be used + * in advertising or publicity pertaining to distribution of the + * software without specific, written prior permission. M.I.T. makes + * no representations about the suitability of this software for any + * purpose. It is provided "as is" without express or implied + * warranty. + * + * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''. M.I.T. DISCLAIMS + * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE, + * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT + * SHALL M.I.T. 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. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +/* + * I din't use "namespace.h" here because none of the relevant utilities + * are threaded, so I'm not concerned about cancellation points or other + * niceties. + */ +#include <limits.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#ifndef LINE_MAX +#define LINE_MAX _POSIX2_LINE_MAX +#endif + +#define _PATH_UTIL_COMPAT "/etc/compat-FreeBSD-4-util" +#define _ENV_UTIL_COMPAT "_COMPAT_FreeBSD_4" + +int +check_utility_compat(const char *utility) +{ + char buf[LINE_MAX]; + char *p, *bp; + int len; + + if ((p = getenv(_ENV_UTIL_COMPAT)) != NULL) { + strlcpy(buf, p, sizeof buf); + } else { + if ((len = readlink(_PATH_UTIL_COMPAT, buf, sizeof buf)) < 0) + return 0; + if (len > sizeof buf) + len = sizeof buf; + buf[len] = '\0'; + } + if (buf[0] == '\0') + return 1; + + bp = buf; + while ((p = strsep(&bp, ",")) != NULL) { + if (strcmp(p, utility) == 0) + return 1; + } + return 0; +} |