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authorRob Landley <rob@landley.net>2019-04-03 13:52:02 -0500
committerRob Landley <rob@landley.net>2019-04-03 13:52:02 -0500
commit7b11e55921aa4e5d3265e96756436ee97641ccf5 (patch)
tree350621538611688432ec69474507e148e8dd4be8
parentaa349873624f2a5d4129c0ef8c33a1495d0b46fc (diff)
downloadtoybox-7b11e55921aa4e5d3265e96756436ee97641ccf5.tar.gz
Autodetect gzip and bz2 for both compression and decompression.
-rw-r--r--toys/pending/tar.c91
1 files changed, 74 insertions, 17 deletions
diff --git a/toys/pending/tar.c b/toys/pending/tar.c
index b7952039..b32a5098 100644
--- a/toys/pending/tar.c
+++ b/toys/pending/tar.c
@@ -475,7 +475,7 @@ static void extract_to_disk(void)
}
}
-static void unpack_tar(void)
+static void unpack_tar(struct tar_hdr *first)
{
struct double_list *walk, *delete;
struct tar_hdr tar;
@@ -484,9 +484,14 @@ static void unpack_tar(void)
char *s;
for (;;) {
- // align to next block and read it
- if (TT.hdr.size%512) skippy(512-TT.hdr.size%512);
- i = readall(TT.fd, &tar, 512);
+ if (first) {
+ memcpy(&tar, first, i = 512);
+ first = 0;
+ } else {
+ // align to next block and read it
+ if (TT.hdr.size%512) skippy(512-TT.hdr.size%512);
+ i = readall(TT.fd, &tar, 512);
+ }
if (i && i != 512) error_exit("read error");
@@ -619,7 +624,7 @@ static void unpack_tar(void)
printf(" %d-%02d-%02d %02d:%02d%s ", 1900+lc->tm_year, 1+lc->tm_mon,
lc->tm_mday, lc->tm_hour, lc->tm_min, FLAG(full_time) ? perm : "");
}
- printf(" %s", TT.hdr.name);
+ printf("%s", TT.hdr.name);
if (TT.hdr.link_target) printf(" -> %s", TT.hdr.link_target);
xputc('\n');
skippy(TT.hdr.size);
@@ -653,10 +658,12 @@ static void trim_list(char **pline, long len)
void tar_main(void)
{
char *s, **args = toys.optargs;
+ int len = 0;
- // When extracting to command
+ // Needed when extracting to command
signal(SIGPIPE, SIG_IGN);
+ // Get possible early errors out of the way
if (!geteuid()) toys.optflags |= FLAG_p;
if (TT.owner) TT.ouid = xgetuid(TT.owner);
if (TT.group) TT.ggid = xgetgid(TT.group);
@@ -667,15 +674,25 @@ void tar_main(void)
for (args = toys.optargs; *args; args++) trim_list(args, strlen(*args));
for (;TT.T; TT.T = TT.T->next) do_lines(xopenro(TT.T->arg), '\n', trim_list);
- // Open archive file
+ // If include file list empty, don't create empty archive
if (FLAG(c)) {
if (!TT.incl) error_exit("empty archive");
TT.fd = 1;
}
- if (TT.f && strcmp(TT.f, "-"))
- TT.fd = xcreate(TT.f, TT.fd*(O_WRONLY|O_CREAT|O_TRUNC), 0666);
- // grab archive inode
+ // nommu reentry for nonseekable input skips this, parent did it for us
+ if (toys.stacktop) {
+ if (TT.f && strcmp(TT.f, "-"))
+ TT.fd = xcreate(TT.f, TT.fd*(O_WRONLY|O_CREAT|O_TRUNC), 0666);
+ // Get destination directory
+ if (TT.C) xchdir(TT.C);
+ }
+
+ // Get destination directory
+ TT.cwd = xabspath(s = xgetcwd(), 1);
+ free(s);
+
+ // Remember archive inode
{
struct stat st;
@@ -685,23 +702,54 @@ void tar_main(void)
}
}
- // Get destination directory
- if (TT.C) xchdir(TT.C);
- TT.cwd = xabspath(s = xgetcwd(), 1);
- free(s);
-
// Are we reading?
if (FLAG(x)||FLAG(t)) {
+ struct tar_hdr *hdr = (void *)(toybuf+sizeof(toybuf)-512);
+
+ // autodetect compression type when not specified
+ if (!FLAG(j)&&!FLAG(z)) {
+ len = xread(TT.fd, hdr, 512);
+ if (len!=512 || strncmp("ustar", hdr->magic, 5)) {
+ // detect gzip and bzip signatures
+ if (SWAP_BE16(*(short *)hdr)==0x1f8b) toys.optflags |= FLAG_z;
+ else if (!memcmp(hdr->name, "BZh", 3)) toys.optflags |= FLAG_j;
+ else error_exit("Not tar");
+
+ // if we can seek back we don't need to loop and copy data
+ if (!lseek(TT.fd, -len, SEEK_CUR)) hdr = 0;
+ }
+ }
+
if (FLAG(j)||FLAG(z)) {
- int pipefd[2] = {TT.fd, -1};
+ int pipefd[2] = {hdr ? -1 : TT.fd, -1}, i;
xpopen_both((char *[]){FLAG(z)?"gunzip":"bunzip2", "-cf", "-", NULL},
pipefd);
close(TT.fd);
TT.fd = pipefd[1];
+
+ // If we autodetected type but then couldn't lseek to put the data back
+ if (hdr) {
+ // dirty trick: move pipefd[0] to 0 so child closes spare copy
+ dup2(pipefd[0], 0);
+ if (pipefd[0]) close(pipefd[0]);
+
+ // Fork a copy of ourselves to handle extraction (reads from zip proc)
+ pipefd[0] = TT.fd;
+ pipefd[1] = 1;
+ xpopen_both(0, pipefd);
+ close(TT.fd);
+
+ // loop writing collated data to zip proc
+ xwrite(0, hdr, len);
+ for (;;) {
+ if ((i = read(0, toybuf, sizeof(toybuf)))<1) return;
+ xwrite(0, toybuf, i);
+ }
+ } else hdr = 0;
}
- unpack_tar();
+ unpack_tar(hdr);
if (TT.seen != TT.incl) {
if (!TT.seen) TT.seen = TT.incl;
while (TT.incl != TT.seen) {
@@ -714,6 +762,15 @@ void tar_main(void)
} else {
struct double_list *dl = TT.incl;
+ // autodetect compression type based on -f name. (Use > to avoid.)
+ if (TT.f && !FLAG(j) && !FLAG(z)) {
+ char *tbz[] = {".tbz", ".tbz2", ".tar.bz", ".tar.bz2"};
+ if (strend(TT.f, ".tgz") || strend(TT.f, ".tar.gz"))
+ toys.optflags |= FLAG_z;
+ else for (len = 0; len<ARRAY_LEN(tbz); len++)
+ if (strend(TT.f, tbz[len])) toys.optflags |= FLAG_j;
+ }
+
if (FLAG(j)||FLAG(z)) {
int pipefd[2] = {-1, TT.fd};