88 lines
2.2 KiB
C
88 lines
2.2 KiB
C
/* ln.c - Create filesystem links
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*
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* Copyright 2012 Andre Renaud <andre@bluewatersys.com>
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*
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* See http://opengroup.org/onlinepubs/9699919799/utilities/ln.html
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USE_LN(NEWTOY(ln, "<1vnfs", TOYFLAG_BIN))
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config LN
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bool "ln"
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default y
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help
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usage: ln [-sfnv] [FROM...] TO
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Create a link between FROM and TO.
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With only one argument, create link in current directory.
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-s Create a symbolic link
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-f Force the creation of the link, even if TO already exists
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-n Symlink at destination treated as file
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-v Verbose
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*/
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#define FOR_ln
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#include "toys.h"
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void ln_main(void)
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{
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char *dest = toys.optargs[--toys.optc], *new;
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struct stat buf;
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int i;
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// With one argument, create link in current directory.
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if (!toys.optc) {
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toys.optc++;
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dest=".";
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}
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// Is destination a directory?
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if (((toys.optflags&FLAG_n) ? lstat : stat)(dest, &buf)
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|| !S_ISDIR(buf.st_mode))
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{
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if (toys.optc>1) error_exit("'%s' not a directory", dest);
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buf.st_mode = 0;
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}
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for (i=0; i<toys.optc; i++) {
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int rc;
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char *oldnew, *try = toys.optargs[i];
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if (S_ISDIR(buf.st_mode)) new = xmprintf("%s/%s", dest, basename(try));
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else new = dest;
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// Force needs to unlink the existing target (if any). Do that by creating
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// a temp version and renaming it over the old one, so we can retain the
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// old file in cases we can't replace it (such as hardlink between mounts).
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oldnew = new;
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if (toys.optflags & FLAG_f) {
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new = xmprintf("%s_XXXXXX", new);
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rc = mkstemp(new);
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if (rc >= 0) {
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close(rc);
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if (unlink(new)) perror_msg("unlink '%s'", new);
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}
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}
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rc = (toys.optflags & FLAG_s) ? symlink(try, new) : link(try, new);
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if (toys.optflags & FLAG_f) {
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if (!rc) {
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int temp;
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rc = rename(new, oldnew);
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temp = errno;
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if (rc && unlink(new)) perror_msg("unlink '%s'", new);
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errno = temp;
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}
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free(new);
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new = oldnew;
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}
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if (rc)
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perror_msg("cannot create %s link from '%s' to '%s'",
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(toys.optflags & FLAG_s) ? "symbolic" : "hard", try, new);
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else
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if (toys.optflags & FLAG_v) fprintf(stderr, "'%s' -> '%s'\n", new, try);
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if (new != dest) free(new);
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}
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}
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