sbase

suckless unix tools
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commit 1d9d17eba2f151996a01218cd16d45d8cd702f97
parent 7dff7d4c83ccb621d2826bc9b13788078df5931a
Author: Hiltjo Posthuma <hiltjo@codemadness.org>
Date:   Fri May  8 12:43:33 +0200

tar: add support for compressing with an external tool

... and add xz, compress and lzma as options

Diffstat:
tar.1 | 13++++++-------
tar.c | 65+++++++++++++++++++++++++++++++++++++++++++++++++++--------------
2 files changed, 57 insertions(+), 21 deletions(-)
diff --git a/tar.1 b/tar.1 @@ -7,12 +7,13 @@ .Sh SYNOPSIS .Nm .Op Fl C Ar dir -.Op Fl j | Fl z +.Op Fl J | Fl Z | Fl a | Fl j | Fl z .Fl x Op Fl m | Fl t .Op Fl f Ar file .Op Ar file ... .Nm .Op Fl C Ar dir +.Op Fl J | Fl Z | Fl a | Fl j | Fl z .Op Fl h .Fl c Ar path ... .Op Fl f Ar file @@ -40,16 +41,14 @@ List all files in the archive. Extract archive. .It Fl h Always dereference symbolic links while recursively traversing directories. -.It Fl j | Fl z -Use bzip2 | gzip decompression. The -.Xr bzip2 1 | -.Xr gzip 1 +.It Fl J | Fl Z | Fl a | Fl j | Fl z +Use xz | compress | lzma | bzip2 | gzip decompression. These utilities must be installed separately. Using these flags is discouraged in favour of the flexibility and clarity of pipes: .Bd -literal -offset indent -$ bzcat archive.tar.bz2 | tar -x -$ zcat archive.tar.gz | tar -x +$ bzip2 -cd archive.tar.bz2 | tar -x +$ gzip -cd archive.tar.gz | tar -x .Ed .Bd -literal -offset indent $ tar -c file ... | bzip2 > archive.tar.bz2 diff --git a/tar.c b/tar.c @@ -67,6 +67,15 @@ static dev_t tardev; static int mflag, vflag; static int filtermode; +static const char *filtertool; + +static const char *filtertools[] = { + ['J'] = "xz", + ['Z'] = "compress", + ['a'] = "lzma", + ['j'] = "bzip2", + ['z'] = "gzip", +}; static void pushent(char *name, time_t mtime) @@ -88,10 +97,34 @@ popent(void) } static int -decomp(int fd) +comp(int fd, const char *tool, const char *flags) +{ + int fds[2]; + + if (pipe(fds) < 0) + eprintf("pipe:"); + + switch (fork()) { + case -1: + eprintf("fork:"); + case 0: + dup2(fd, 1); + dup2(fds[0], 0); + close(fds[0]); + close(fds[1]); + + execlp(tool, tool, flags, NULL); + weprintf("execlp %s:", tool); + _exit(1); + } + close(fds[0]); + return fds[1]; +} + +static int +decomp(int fd, const char *tool, const char *flags) { int fds[2]; - char *tool; if (pipe(fds) < 0) eprintf("pipe:"); @@ -105,8 +138,7 @@ decomp(int fd) close(fds[0]); close(fds[1]); - tool = (filtermode == 'j') ? "bzip2" : "gzip"; - execlp(tool, tool, "-cd", NULL); + execlp(tool, tool, flags, NULL); weprintf("execlp %s:", tool); _exit(1); } @@ -390,7 +422,7 @@ bad: } static void -xt(int argc, char *argv[], int (*fn)(char *, ssize_t, char[BLKSIZ])) +xt(int argc, char *argv[], int mode) { char b[BLKSIZ], fname[256 + 1], *p; struct timeval times[2]; @@ -398,6 +430,7 @@ xt(int argc, char *argv[], int (*fn)(char *, ssize_t, char[BLKSIZ])) struct ent *ent; long size; int i, n; + int (*fn)(char *, ssize_t, char[BLKSIZ]) = (mode == 'x') ? unarchive : print; while (eread(tarfd, b, BLKSIZ) > 0 && h->name[0]) { chktar(h); @@ -451,8 +484,8 @@ xt(int argc, char *argv[], int (*fn)(char *, ssize_t, char[BLKSIZ])) static void usage(void) { - eprintf("usage: %s [-C dir] [-j | -z] -x [-m | -t] [-f file] [file ...]\n" - " %s [-C dir] [-h] -c path ... [-f file]\n", argv0, argv0); + eprintf("usage: %s [-C dir] [-J | -Z | -a | -j | -z] -x [-m | -t] [-f file] [file ...]\n" + " %s [-C dir] [-J | -Z | -a | -j | -z] [-h] -c path ... [-f file]\n", argv0, argv0); } int @@ -479,9 +512,13 @@ main(int argc, char *argv[]) case 'm': mflag = 1; break; + case 'J': + case 'Z': + case 'a': case 'j': case 'z': filtermode = ARGC(); + filtertool = filtertools[filtermode]; break; case 'h': r.follow = 'L'; @@ -496,7 +533,7 @@ main(int argc, char *argv[]) if (!mode) usage(); if (mode == 'c') - if (!argc || filtermode) + if (!argc) usage(); switch (mode) { @@ -512,6 +549,9 @@ main(int argc, char *argv[]) tardev = st.st_dev; } + if (filtertool) + tarfd = comp(tarfd, filtertool, "-cf"); + if (chdir(dir) < 0) eprintf("chdir %s:", dir); for (; *argv; argc--, argv++) @@ -526,18 +566,15 @@ main(int argc, char *argv[]) eprintf("open %s:", file); } - switch (filtermode) { - case 'j': - case 'z': + if (filtertool) { fd = tarfd; - tarfd = decomp(tarfd); + tarfd = decomp(tarfd, filtertool, "-cd"); close(fd); - break; } if (chdir(dir) < 0) eprintf("chdir %s:", dir); - xt(argc, argv, (mode == 'x') ? unarchive : print); + xt(argc, argv, mode); break; }