Den 06/10/2010 kl. 13.07 skrev Erik Cederstrand: > Is something like the following acceptable? Without risking changes to > buildworld/distribution just now, this would allow me to dump contents of an > archive and re-insert them with '0' for mtime, uid and gid before checking > checksums, without affecting normal ar behaviour.
Great, I didn't even see the discussion on this list recently: http://lists.freebsd.org/pipermail/freebsd-hackers/2010-September/033005.html Anyway, I added file mode to the patch. Apparently recent binutils also added this feature. I haven't looked at their patch, but chance has it I used the same option '-D'. I'm sure the file mode I'm setting in line 175 of write.c is wrong (obj->md = 100644), but I couldn't quite figure out how to set the value to rw-r--r--. Here's the new patch: Index: ar.1 =================================================================== --- ar.1 (revision 213478) +++ ar.1 (working copy) @@ -62,6 +62,7 @@ .Op Fl a Ar position-after .Op Fl b Ar position-before .Op Fl c +.Op Fl D .Op Fl i Ar position-before .Op Fl j .Op Fl s @@ -179,6 +180,14 @@ .Ar archive . The archive's symbol table, if present, is updated to reflect the new contents of the archive. +.It Fl D +When used in combination with the +.Fl r +option, insterts 0's instead of the real mtime, uid and gid values +and 644 instead of file mode from the members named by arguments +.Ar files ... . +This ensures that checksums on the resulting archives are reproducible +when member contents are identical. .It Fl f Synonymous with option .Fl T . Index: ar.c =================================================================== --- ar.c (revision 213478) +++ ar.c (working copy) @@ -154,7 +154,7 @@ } } - while ((opt = getopt_long(argc, argv, "abCcdfijlMmopqrSsTtuVvxz", + while ((opt = getopt_long(argc, argv, "abCcdDfijlMmopqrSsTtuVvxz", longopts, NULL)) != -1) { switch(opt) { case 'a': @@ -173,6 +173,9 @@ case 'd': set_mode(bsdar, opt); break; + case 'D': + bsdar->options |= AR_D; + break; case 'f': case 'T': bsdar->options |= AR_TR; @@ -357,8 +360,8 @@ (void)fprintf(stderr, "\tar -m [-Tabijsvz] position archive file ...\n"); (void)fprintf(stderr, "\tar -p [-Tv] archive [file ...]\n"); (void)fprintf(stderr, "\tar -q [-Tcjsvz] archive file ...\n"); - (void)fprintf(stderr, "\tar -r [-Tcjsuvz] archive file ...\n"); - (void)fprintf(stderr, "\tar -r [-Tabcijsuvz] position archive file ...\n"); + (void)fprintf(stderr, "\tar -r [-TcDjsuvz] archive file ...\n"); + (void)fprintf(stderr, "\tar -r [-TabcDijsuvz] position archive file ...\n"); (void)fprintf(stderr, "\tar -s [-jz] archive\n"); (void)fprintf(stderr, "\tar -t [-Tv] archive [file ...]\n"); (void)fprintf(stderr, "\tar -x [-CTouv] archive [file ...]\n"); Index: ar.h =================================================================== --- ar.h (revision 213478) +++ ar.h (working copy) @@ -43,6 +43,7 @@ #define AR_U 0x0200 /* only extract or update newer members.*/ #define AR_V 0x0400 /* verbose mode */ #define AR_Z 0x0800 /* gzip compression */ +#define AR_D 0x1000 /* insert members with dummy mode, mtime, uid and gid */ #define DEF_BLKSZ 10240 /* default block size */ Index: write.c =================================================================== --- write.c (revision 213478) +++ write.c (working copy) @@ -163,11 +163,23 @@ if (mtime != 0 && bsdar->options & AR_U && sb.st_mtime <= mtime) goto giveup; - obj->uid = sb.st_uid; - obj->gid = sb.st_gid; - obj->md = sb.st_mode; + /* + * When option '-D' is specified, mtime and UID / GID from the file + * will be replaced with 0, and file mode with 644. This ensures that + * checksums will match for two archives containing the exact same files. + */ + if (bsdar->options & AR_D) { + obj->uid = 0; + obj->gid = 0; + obj->mtime = 0; + obj->md = 100644; + } else { + obj->uid = sb.st_uid; + obj->gid = sb.st_gid; + obj->mtime = sb.st_mtime; + obj->md = sb.st_mode; + } obj->size = sb.st_size; - obj->mtime = sb.st_mtime; obj->dev = sb.st_dev; obj->ino = sb.st_ino; @@ -621,7 +633,10 @@ bsdar->options & AR_S) { entry = archive_entry_new(); archive_entry_copy_pathname(entry, "/"); - archive_entry_set_mtime(entry, time(NULL), 0); + if (bsdar->options & AR_O) + archive_entry_set_mtime(entry, 0, 0); + else + archive_entry_set_mtime(entry, time(NULL), 0); archive_entry_set_size(entry, (bsdar->s_cnt + 1) * sizeof(uint32_t) + bsdar->s_sn_sz); AC(archive_write_header(a, entry)); Thanks, Erik
