2015-12-23 00:50:04 +00:00

94 lines
2.8 KiB
C

/*
* Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009
* The President and Fellows of Harvard College.
*
* 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 UNIVERSITY 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 UNIVERSITY 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.
*/
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <err.h>
/*
* ln - hardlink or symlink files
*
* Usage: ln oldfile newfile
* ln -s symlinkcontents symlinkfile
*/
/*
* Create a symlink with filename PATH that contains text TEXT.
* When fed to ls -l, this produces something that looks like
*
* lrwxrwxrwx [stuff] PATH -> TEXT
*/
static
void
dosymlink(const char *text, const char *path)
{
if (symlink(text, path)) {
err(1, "%s", path);
}
}
/*
* Create a hard link such that NEWFILE names the same file as
* OLDFILE. Since it's a hard link, the two names for the file
* are equal; both are the "real" file.
*/
static
void
dohardlink(const char *oldfile, const char *newfile)
{
if (link(oldfile, newfile)) {
err(1, "%s or %s", oldfile, newfile);
exit(1);
}
}
int
main(int argc, char *argv[])
{
/*
* Just do whatever was asked for.
*
* We don't allow the Unix model where you can do
* ln [-s] file1 file2 file3 destination-directory
*/
if (argc==4 && !strcmp(argv[1], "-s")) {
dosymlink(argv[2], argv[3]);
}
else if (argc==3) {
dohardlink(argv[1], argv[2]);
}
else {
warnx("Usage: ln oldfile newfile");
errx(1, " ln -s symlinkcontents symlinkfile\n");
}
return 0;
}