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Repository switched to git at https://github.com/landley/toybox
author Rob Landley <rob@landley.net>
date Thu, 09 Apr 2015 02:28:32 -0500
parents 58d9f1b61f0a
children
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1 /* ln.c - Create filesystem links
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2 *
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3 * Copyright 2012 Andre Renaud <andre@bluewatersys.com>
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4 *
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5 * See http://opengroup.org/onlinepubs/9699919799/utilities/ln.html
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6
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7 USE_LN(NEWTOY(ln, "<1vnfs", TOYFLAG_BIN))
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8
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9 config LN
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10 bool "ln"
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11 default y
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12 help
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13 usage: ln [-sfnv] [FROM...] TO
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15 Create a link between FROM and TO.
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16 With only one argument, create link in current directory.
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18 -s Create a symbolic link
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19 -f Force the creation of the link, even if TO already exists
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20 -n Symlink at destination treated as file
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21 -v Verbose
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22 */
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23
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7e846e281e38 New build infrastructure to generate FLAG_ macros and TT alias, #define FOR_commandname before #including toys.h to trigger it. Rename DEFINE_GLOBALS() to just GLOBALS() (because I could never remember if it was DECLARE_GLOBALS). Convert existing commands to use new infrastructure, and replace optflag constants with FLAG_ macros where appropriate.
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24 #define FOR_ln
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25 #include "toys.h"
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26
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27 void ln_main(void)
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28 {
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29 char *dest = toys.optargs[--toys.optc], *new;
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30 struct stat buf;
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31 int i;
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32
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33 // With one argument, create link in current directory.
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34 if (!toys.optc) {
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35 toys.optc++;
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36 dest=".";
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37 }
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39 // Is destination a directory?
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40 if (((toys.optflags&FLAG_n) ? lstat : stat)(dest, &buf)
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41 || !S_ISDIR(buf.st_mode))
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42 {
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43 if (toys.optc>1) error_exit("'%s' not a directory", dest);
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44 buf.st_mode = 0;
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45 }
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46
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47 for (i=0; i<toys.optc; i++) {
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48 int rc;
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49 char *oldnew, *try = toys.optargs[i];
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50
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51 if (S_ISDIR(buf.st_mode)) new = xmprintf("%s/%s", dest, basename(try));
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52 else new = dest;
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53
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54 // Force needs to unlink the existing target (if any). Do that by creating
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55 // a temp version and renaming it over the old one, so we can retain the
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56 // old file in cases we can't replace it (such as hardlink between mounts).
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57 oldnew = new;
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58 if (toys.optflags & FLAG_f) {
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59 new = xmprintf("%s_XXXXXX", new);
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60 rc = mkstemp(new);
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61 if (rc >= 0) {
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62 close(rc);
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63 if (unlink(new)) perror_msg("unlink '%s'", new);
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64 }
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65 }
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67 rc = (toys.optflags & FLAG_s) ? symlink(try, new) : link(try, new);
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68 if (toys.optflags & FLAG_f) {
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69 if (!rc) {
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70 int temp;
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71
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72 rc = rename(new, oldnew);
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73 temp = errno;
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74 if (rc && unlink(new)) perror_msg("unlink '%s'", new);
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75 errno = temp;
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76 }
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77 free(new);
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78 new = oldnew;
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79 }
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80 if (rc)
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81 perror_msg("cannot create %s link from '%s' to '%s'",
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82 (toys.optflags & FLAG_s) ? "symbolic" : "hard", try, new);
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83 else
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84 if (toys.optflags & FLAG_v) fprintf(stderr, "'%s' -> '%s'\n", new, try);
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85
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86 if (new != dest) free(new);
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87 }
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88 }