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cp: add support for -s, -l. Fix free(nonmalloc) bug.

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Add doc on POSIX's rules on -i and -f (insane!).
ln: make "ln dangling_symlink new_link" work.
This commit is contained in:
Denis Vlasenko
2006-10-21 23:40:20 +00:00
parent 8d73c35916
commit f24e1f40e0
6 changed files with 190 additions and 161 deletions
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214
libbb/copy_file.c
View File

@ -10,31 +10,53 @@
#include "libbb.h"
static int retry_overwrite(const char *dest, int flags)
{
if (!(flags & (FILEUTILS_FORCE|FILEUTILS_INTERACTIVE))) {
fprintf(stderr, "'%s' exists\n", dest);
return -1;
}
if (flags & FILEUTILS_INTERACTIVE) {
fprintf(stderr, "%s: overwrite '%s'? ", applet_name, dest);
if (!bb_ask_confirmation())
return 0; // not allowed to overwrite
}
if (unlink(dest) < 0) {
bb_perror_msg("cannot remove '%s'", dest);
return -1; // error
}
return 1; // ok (to try again)
}
int copy_file(const char *source, const char *dest, int flags)
{
struct stat source_stat;
struct stat dest_stat;
int dest_exists = 0;
int status = 0;
signed char dest_exists = 0;
signed char ovr;
if ((!(flags & FILEUTILS_DEREFERENCE) &&
lstat(source, &source_stat) < 0) ||
((flags & FILEUTILS_DEREFERENCE) &&
stat(source, &source_stat) < 0)) {
bb_perror_msg("%s", source);
#define FLAGS_DEREF (flags & FILEUTILS_DEREFERENCE)
if ((FLAGS_DEREF ? stat : lstat)(source, &source_stat) < 0) {
// This may be a dangling symlink.
// Making [sym]links to dangling symlinks works, so...
if (flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK))
goto make_links;
bb_perror_msg("cannot stat '%s'", source);
return -1;
}
if (lstat(dest, &dest_stat) < 0) {
if (errno != ENOENT) {
bb_perror_msg("unable to stat `%s'", dest);
bb_perror_msg("cannot stat '%s'", dest);
return -1;
}
} else {
if (source_stat.st_dev == dest_stat.st_dev &&
source_stat.st_ino == dest_stat.st_ino)
{
bb_error_msg("`%s' and `%s' are the same file", source, dest);
if (source_stat.st_dev == dest_stat.st_dev
&& source_stat.st_ino == dest_stat.st_ino
) {
bb_error_msg("'%s' and '%s' are the same file", source, dest);
return -1;
}
dest_exists = 1;
@ -46,14 +68,14 @@ int copy_file(const char *source, const char *dest, int flags)
mode_t saved_umask = 0;
if (!(flags & FILEUTILS_RECUR)) {
bb_error_msg("%s: omitting directory", source);
bb_error_msg("omitting directory '%s'", source);
return -1;
}
/* Create DEST. */
if (dest_exists) {
if (!S_ISDIR(dest_stat.st_mode)) {
bb_error_msg("`%s' is not a directory", dest);
bb_error_msg("target '%s' is not a directory", dest);
return -1;
}
} else {
@ -67,7 +89,7 @@ int copy_file(const char *source, const char *dest, int flags)
if (mkdir(dest, mode) < 0) {
umask(saved_umask);
bb_perror_msg("cannot create directory `%s'", dest);
bb_perror_msg("cannot create directory '%s'", dest);
return -1;
}
@ -75,7 +97,8 @@ int copy_file(const char *source, const char *dest, int flags)
}
/* Recursively copy files in SOURCE. */
if ((dp = opendir(source)) == NULL) {
dp = opendir(source);
if (dp == NULL) {
status = -1;
goto preserve_status;
}
@ -84,7 +107,7 @@ int copy_file(const char *source, const char *dest, int flags)
char *new_source, *new_dest;
new_source = concat_subpath_file(source, d->d_name);
if(new_source == NULL)
if (new_source == NULL)
continue;
new_dest = concat_path_file(dest, d->d_name);
if (copy_file(new_source, new_dest, flags) < 0)
@ -92,103 +115,119 @@ int copy_file(const char *source, const char *dest, int flags)
free(new_source);
free(new_dest);
}
/* closedir have only EBADF error, but "dp" not changes */
closedir(dp);
if (!dest_exists &&
chmod(dest, source_stat.st_mode & ~saved_umask) < 0) {
bb_perror_msg("unable to change permissions of `%s'", dest);
if (!dest_exists
&& chmod(dest, source_stat.st_mode & ~saved_umask) < 0
) {
bb_perror_msg("cannot change permissions of '%s'", dest);
status = -1;
}
} else if (S_ISREG(source_stat.st_mode) ||
(S_ISLNK(source_stat.st_mode) && (flags & FILEUTILS_DEREFERENCE)))
{
} else if (flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) {
int (*lf)(const char *oldpath, const char *newpath);
make_links:
// Hmm... maybe
// if (DEREF && MAKE_SOFTLINK) source = realpath(source) ?
// (but realpath returns NULL on dangling symlinks...)
lf = (flags & FILEUTILS_MAKE_SOFTLINK) ? symlink : link;
if (lf(source, dest) < 0) {
ovr = retry_overwrite(dest, flags);
if (ovr <= 0)
return ovr;
if (lf(source, dest) < 0) {
bb_perror_msg("cannot create link '%s'", dest);
return -1;
}
}
return 0;
} else if (S_ISREG(source_stat.st_mode)
// Huh? DEREF uses stat, which never returns links IIRC...
|| (FLAGS_DEREF && S_ISLNK(source_stat.st_mode))
) {
int src_fd;
int dst_fd;
if (ENABLE_FEATURE_PRESERVE_HARDLINKS) {
char *link_name;
if (!(flags & FILEUTILS_DEREFERENCE) &&
is_in_ino_dev_hashtable(&source_stat, &link_name)) {
if (!FLAGS_DEREF
&& is_in_ino_dev_hashtable(&source_stat, &link_name)
) {
if (link(link_name, dest) < 0) {
bb_perror_msg("unable to link `%s'", dest);
return -1;
ovr = retry_overwrite(dest, flags);
if (ovr <= 0)
return ovr;
if (link(link_name, dest) < 0) {
bb_perror_msg("cannot create link '%s'", dest);
return -1;
}
}
return 0;
}
// TODO: probably is_in_.. and add_to_...
// can be combined: find_or_add_...
add_to_ino_dev_hashtable(&source_stat, dest);
}
src_fd = open(source, O_RDONLY);
if (src_fd == -1) {
bb_perror_msg("unable to open `%s'", source);
return(-1);
bb_perror_msg("cannot open '%s'", source);
return -1;
}
if (dest_exists) {
if (flags & FILEUTILS_INTERACTIVE) {
fprintf(stderr, "%s: overwrite `%s'? ", applet_name, dest);
if (!bb_ask_confirmation()) {
close (src_fd);
return 0;
}
}
dst_fd = open(dest, O_WRONLY|O_TRUNC);
if (dst_fd == -1) {
if (!(flags & FILEUTILS_FORCE)) {
bb_perror_msg("unable to open `%s'", dest);
close(src_fd);
return -1;
}
if (unlink(dest) < 0) {
bb_perror_msg("unable to remove `%s'", dest);
close(src_fd);
return -1;
}
goto dest_removed;
}
} else {
dest_removed:
dst_fd = open(dest, O_WRONLY|O_CREAT, source_stat.st_mode);
if (dst_fd == -1) {
bb_perror_msg("unable to open `%s'", dest);
// POSIX: if exists and -i, ask (w/o -i assume yes).
// Then open w/o EXCL.
// If open still fails and -f, try unlink, then try open again.
// Result: a mess:
// If dest is a softlink, we overwrite softlink's destination!
// (or fail, if it points to dir/nonexistent location/etc).
// This is strange, but POSIX-correct.
// coreutils cp has --remove-destination to override this...
dst_fd = open(dest, (flags & FILEUTILS_INTERACTIVE)
? O_WRONLY|O_CREAT|O_TRUNC|O_EXCL
: O_WRONLY|O_CREAT|O_TRUNC, source_stat.st_mode);
if (dst_fd == -1) {
// We would not do POSIX insanity. -i asks,
// then _unlinks_ the offender. Presto.
// Or else we will end up having 3 open()s!
ovr = retry_overwrite(dest, flags);
if (ovr <= 0) {
close(src_fd);
return(-1);
return ovr;
}
dst_fd = open(dest, O_WRONLY|O_CREAT|O_TRUNC, source_stat.st_mode);
if (dst_fd == -1) {
bb_perror_msg("cannot open '%s'", dest);
close(src_fd);
return -1;
}
}
if (bb_copyfd_eof(src_fd, dst_fd) == -1)
status = -1;
if (close(dst_fd) < 0) {
bb_perror_msg("unable to close `%s'", dest);
bb_perror_msg("cannot close '%s'", dest);
status = -1;
}
if (close(src_fd) < 0) {
bb_perror_msg("unable to close `%s'", source);
bb_perror_msg("cannot close '%s'", source);
status = -1;
}
} else if (S_ISBLK(source_stat.st_mode) || S_ISCHR(source_stat.st_mode) ||
S_ISSOCK(source_stat.st_mode) || S_ISFIFO(source_stat.st_mode) ||
S_ISLNK(source_stat.st_mode)) {
} else if (S_ISBLK(source_stat.st_mode) || S_ISCHR(source_stat.st_mode)
|| S_ISSOCK(source_stat.st_mode) || S_ISFIFO(source_stat.st_mode)
|| S_ISLNK(source_stat.st_mode)
) {
// We are lazy here, a bit lax with races...
if (dest_exists) {
if((flags & FILEUTILS_FORCE) == 0) {
fprintf(stderr, "`%s' exists\n", dest);
return -1;
}
if(unlink(dest) < 0) {
bb_perror_msg("unable to remove `%s'", dest);
return -1;
}
ovr = retry_overwrite(dest, flags);
if (ovr <= 0)
return ovr;
}
if (S_ISFIFO(source_stat.st_mode)) {
if (mkfifo(dest, source_stat.st_mode) < 0) {
bb_perror_msg("cannot create fifo `%s'", dest);
bb_perror_msg("cannot create fifo '%s'", dest);
return -1;
}
} else if (S_ISLNK(source_stat.st_mode)) {
@ -196,20 +235,21 @@ dest_removed:
lpath = xreadlink(source);
if (symlink(lpath, dest) < 0) {
bb_perror_msg("cannot create symlink `%s'", dest);
bb_perror_msg("cannot create symlink '%s'", dest);
free(lpath);
return -1;
}
free(lpath);
if (flags & FILEUTILS_PRESERVE_STATUS)
if (lchown(dest, source_stat.st_uid, source_stat.st_gid) < 0)
bb_perror_msg("unable to preserve ownership of `%s'", dest);
bb_perror_msg("cannot preserve %s of '%s'", "ownership", dest);
return 0;
} else {
if (mknod(dest, source_stat.st_mode, source_stat.st_rdev) < 0) {
bb_perror_msg("unable to create `%s'", dest);
bb_perror_msg("cannot create '%s'", dest);
return -1;
}
}
@ -218,22 +258,24 @@ dest_removed:
return -1;
}
preserve_status:
preserve_status:
if (flags & FILEUTILS_PRESERVE_STATUS) {
if (flags & FILEUTILS_PRESERVE_STATUS
/* Cannot happen: */
/* && !(flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) */
) {
struct utimbuf times;
char *msg="unable to preserve %s of `%s'";
times.actime = source_stat.st_atime;
times.modtime = source_stat.st_mtime;
if (utime(dest, &times) < 0)
bb_perror_msg(msg, "times", dest);
bb_perror_msg("cannot preserve %s of '%s'", "times", dest);
if (chown(dest, source_stat.st_uid, source_stat.st_gid) < 0) {
source_stat.st_mode &= ~(S_ISUID | S_ISGID);
bb_perror_msg(msg, "ownership", dest);
bb_perror_msg("cannot preserve %s of '%s'", "ownership", dest);
}
if (chmod(dest, source_stat.st_mode) < 0)
bb_perror_msg(msg, "permissions", dest);
bb_perror_msg("cannot preserve %s of '%s'", "permissions", dest);
}
return status;