Путь: Toys/POSIX, команды версии: Ver.4 Ver.9 Комментарии в файле cp.c : Команд: 3 cp
mv
install
Исходный текст в файле cp.c #define FORCE_FLAGS
#define FOR_cp
#include "toys.h"
GLOBALS(
union {
// install's options
struct {
char *g, *o, *m, *t;
} i;
// cp's options
struct {
char *t, *preserve;
} c;
};
char *destname;
struct stat top;
int (*callback)(struct dirtree *try);
uid_t uid;
gid_t gid;
int pflags;
)
struct cp_preserve {
char *name;
} static const cp_preserve[] = TAGGED_ARRAY(CP,
{"mode"}, {"ownership"}, {"timestamps"}, {"context"}, {"xattr"},
);
// Callback from dirtree_read() for each file/directory under a source dir.
static int cp_node(struct dirtree *try)
{
int fdout = -1, cfd = try->parent ? try->parent->extra : AT_FDCWD,
save = DIRTREE_SAVE*(CFG_MV && toys.which->name[0] == 'm'), rc = 0,
tfd = dirtree_parentfd(try);
unsigned flags = toys.optflags;
char *s = 0, *catch = try->parent ? try->name : TT.destname, *err = "%s";
struct stat cst;
if (!dirtree_notdotdot(try)) return 0;
// If returning from COMEAGAIN, jump straight to -p logic at end.
if (S_ISDIR(try->st.st_mode) && try->again) {
fdout = try->extra;
err = 0;
// If mv child had a problem, free data and don't try to delete parent dir.
if (try->child) {
save = 0;
llist_traverse(try->child, free);
}
} else {
// -d is only the same as -r for symlinks, not for directories
if (S_ISLNK(try->st.st_mode) && (flags & FLAG_d)) flags |= FLAG_r;
// Detect recursive copies via repeated top node (cp -R .. .) or
// identical source/target (fun with hardlinks).
if ((same_file(&TT.top, &try->st) && (catch = TT.destname))
|| (!fstatat(cfd, catch, &cst, 0) && same_file(&cst, &try->st)))
{
error_msg("'%s' is '%s'", catch, err = dirtree_path(try, 0));
free(err);
return save;
}
// Handle -inuvF
if (!faccessat(cfd, catch, F_OK, 0) && !S_ISDIR(cst.st_mode)) {
if (S_ISDIR(try->st.st_mode))
error_msg("dir at '%s'", s = dirtree_path(try, 0));
else if ((flags & FLAG_F) && unlinkat(cfd, catch, 0))
error_msg("unlink '%s'", catch);
else if (flags & FLAG_i) {
fprintf(stderr, "%s: overwrite '%s'", toys.which->name,
s = dirtree_path(try, 0));
if (yesno(0)) rc++;
} else if (!((flags&FLAG_u) && nanodiff(&try->st.st_mtim, &cst.st_mtim)>0)
&& !(flags & FLAG_n)) rc++;
free(s);
if (!rc) return save;
}
if (flags & FLAG_v) {
printf("%s '%s'\n", toys.which->name, s = dirtree_path(try, 0));
free(s);
}
// Loop for -f retry after unlink
do {
// directory, hardlink, symlink, mknod (char, block, fifo, socket), file
// Copy directory
if (S_ISDIR(try->st.st_mode)) {
struct stat st2;
if (!(flags & (FLAG_a|FLAG_r))) {
err = "Skipped dir '%s'";
catch = try->name;
break;
}
// Always make directory writeable to us, so we can create files in it.
//
// Yes, there's a race window between mkdir() and open() so it's
// possible that -p can be made to chown a directory other than the one
// we created. The closest we can do to closing this is make sure
// that what we open _is_ a directory rather than something else.
if (!mkdirat(cfd, catch, try->st.st_mode | 0200) || errno == EEXIST)
if (-1 != (try->extra = openat(cfd, catch, O_NOFOLLOW)))
if (!fstat(try->extra, &st2) && S_ISDIR(st2.st_mode))
return DIRTREE_COMEAGAIN | (DIRTREE_SYMFOLLOW*!!FLAG(L));
// Hardlink
} else if (flags & FLAG_l) {
if (!linkat(tfd, try->name, cfd, catch, 0)) err = 0;
// Copy tree as symlinks. For non-absolute paths this involves
// appending the right number of .. entries as you go down the tree.
} else if (flags & FLAG_s) {
char *s;
struct dirtree *or;
int dotdots = 0;
s = dirtree_path(try, 0);
for (or = try; or->parent; or = or->parent) dotdots++;
if (*or->name == '/') dotdots = 0;
if (dotdots) {
char *s2 = xmprintf("%*c%s", 3*dotdots, ' ', s);
free(s);
s = s2;
while(dotdots--) {
memcpy(s2, "../", 3);
s2 += 3;
}
}
if (!symlinkat(s, cfd, catch)) {
err = 0;
fdout = AT_FDCWD;
}
free(s);
// Do something _other_ than copy contents of a file?
} else if (!S_ISREG(try->st.st_mode)
&& (try->parent || (flags & (FLAG_a|FLAG_P|FLAG_r))))
{
// make symlink, or make block/char/fifo/socket
if (S_ISLNK(try->st.st_mode)
? readlinkat0(tfd, try->name, toybuf, sizeof(toybuf)) &&
(!unlinkat(cfd, catch, 0) || ENOENT == errno) &&
!symlinkat(toybuf, cfd, catch)
: !mknodat(cfd, catch, try->st.st_mode, try->st.st_rdev))
{
err = 0;
fdout = AT_FDCWD;
}
// Copy contents of file.
} else {
int fdin, ii;
fdin = openat(tfd, try->name, O_RDONLY);
if (fdin < 0) {
catch = try->name;
break;
}
// When copying contents use symlink target's attributes
if (S_ISLNK(try->st.st_mode)) fstat(fdin, &try->st);
fdout = openat(cfd, catch, O_RDWR|O_CREAT|O_TRUNC, try->st.st_mode);
if (fdout >= 0) {
xsendfile(fdin, fdout);
err = 0;
}
// We only copy xattrs for files because there's no flistxattrat()
if (TT.pflags&(_CP_xattr|_CP_context)) {
ssize_t listlen = xattr_flist(fdin, 0, 0), len;
char *name, *value, *list;
if (listlen>0) {
list = xmalloc(listlen);
xattr_flist(fdin, list, listlen);
list[listlen-1] = 0; // I do not trust this API.
for (name = list; name-list < listlen; name += strlen(name)+1) {
// context copies security, xattr copies everything else
ii = strncmp(name, "security.", 9) ? _CP_xattr : _CP_context;
if (!(TT.pflags&ii)) continue;
if ((len = xattr_fget(fdin, name, 0, 0))>0) {
value = xmalloc(len);
if (len == xattr_fget(fdin, name, value, len))
if (xattr_fset(fdout, name, value, len, 0))
perror_msg("%s setxattr(%s=%s)", catch, name, value);
free(value);
}
}
free(list);
}
}
close(fdin);
}
} while (err && (flags & (FLAG_f|FLAG_n)) && !unlinkat(cfd, catch, 0));
}
// Did we make a thing?
if (fdout != -1) {
// Inability to set --preserve isn't fatal, some require root access.
// ownership
if (TT.pflags & _CP_ownership) {
// permission bits already correct for mknod and don't apply to symlink
// If we can't get a filehandle to the actual object, use racy functions
if (fdout == AT_FDCWD)
rc = fchownat(cfd, catch, try->st.st_uid, try->st.st_gid,
AT_SYMLINK_NOFOLLOW);
else rc = fchown(fdout, try->st.st_uid, try->st.st_gid);
if (rc && !geteuid()) {
char *pp;
perror_msg("chown '%s'", pp = dirtree_path(try, 0));
free(pp);
}
}
// timestamp
if (TT.pflags & _CP_timestamps) {
struct timespec times[] = {try->st.st_atim, try->st.st_mtim};
if (fdout == AT_FDCWD) utimensat(cfd, catch, times, AT_SYMLINK_NOFOLLOW);
else futimens(fdout, times);
}
// mode comes last because other syscalls can strip suid bit
if (fdout != AT_FDCWD) {
if (TT.pflags & _CP_mode) fchmod(fdout, try->st.st_mode);
xclose(fdout);
}
if (save)
if (unlinkat(tfd, try->name, S_ISDIR(try->st.st_mode) ? AT_REMOVEDIR :0))
err = "%s";
}
if (err) {
if (catch == try->name) {
s = dirtree_path(try, 0);
while (try->parent) try = try->parent;
catch = xmprintf("%s%s", TT.destname, s+strlen(try->name));
free(s);
s = catch;
} else s = 0;
perror_msg(err, catch);
free(s);
}
return 0;
}
void cp_main(void)
{
char *tt = *toys.which->name == 'i' ? TT.i.t : TT.c.t,
*destname = tt ? : toys.optargs[--toys.optc];
int i, destdir = !stat(destname, &TT.top);
if (!toys.optc) error_exit("Needs 2 arguments");
if (!destdir && errno==ENOENT && FLAG(D)) {
if (tt && mkpathat(AT_FDCWD, tt, 0777, MKPATHAT_MAKE|MKPATHAT_MKLAST))
perror_exit("-t '%s'", tt);
destdir = 1;
} else {
destdir = destdir && S_ISDIR(TT.top.st_mode);
if (!destdir && (toys.optc>1 || FLAG(D) || tt))
error_exit("'%s' not directory", destname);
}
if (FLAG(T)) {
if (toys.optc>1) help_exit("Max 2 arguments");
if (destdir) error_exit("'%s' is a directory", destname);
}
if (FLAG(a)||FLAG(p)) TT.pflags = _CP_mode|_CP_ownership|_CP_timestamps;
// Not using comma_args() (yet?) because interpeting as letters.
if (FLAG(preserve)) {
char *pre = xstrdup(TT.c.preserve ? TT.c.preserve : "mot"), *s;
if (comma_remove(pre, "all")) TT.pflags = ~0;
for (i=0; i<ARRAY_LEN(cp_preserve); i++)
while (comma_remove(pre, cp_preserve[i].name)) TT.pflags |= 1<<i;
if (*pre) {
// Try to interpret as letters, commas won't set anything this doesn't.
for (s = pre; *s; s++) {
for (i=0; i<ARRAY_LEN(cp_preserve); i++)
if (*s == *cp_preserve[i].name) break;
if (i == ARRAY_LEN(cp_preserve)) {
if (*s == 'a') TT.pflags = ~0;
else break;
} else TT.pflags |= 1<<i;
}
if (*s) error_exit("bad --preserve=%s", pre);
}
free(pre);
}
if (TT.pflags & _CP_mode) umask(0);
if (!TT.callback) TT.callback = cp_node;
// Loop through sources
for (i=0; i<toys.optc; i++) {
char *src = toys.optargs[i], *trail;
int send = 1;
if (!(trail = strrchr(src, '/')) || trail[1]) trail = 0;
else while (trail>src && *trail=='/') *trail-- = 0;
if (destdir) {
char *s = FLAG(D) ? src : getbasename(src);
TT.destname = xmprintf("%s/%s", destname, s);
if (FLAG(D)) {
if (!(s = fileunderdir(TT.destname, destname))) {
error_msg("%s not under %s", TT.destname, destname);
continue;
}
// TODO: .. follows abspath, not links...
free(s);
mkpath(TT.destname);
}
} else TT.destname = destname;
// "mv across devices" triggers cp fallback path, so set that as default
errno = EXDEV;
if (CFG_MV && toys.which->name[0] == 'm') {
int force = FLAG(f), no_clobber = FLAG(n);
if (!force || no_clobber) {
struct stat st;
int exists = !stat(TT.destname, &st);
// Prompt if -i or file isn't writable. Technically "is writable" is
// more complicated (022 is not writeable by the owner, just everybody
// _else_) but I don't care.
if (exists && (FLAG(i) || (!(st.st_mode & 0222) && isatty(0)))) {
fprintf(stderr, "%s: overwrite '%s'", toys.which->name, TT.destname);
if (!yesno(0)) send = 0;
else unlink(TT.destname);
}
// if -n and dest exists, don't try to rename() or copy
if (exists && no_clobber) send = 0;
}
if (send) send = rename(src, TT.destname);
if (trail) trail[1] = '/';
}
// Copy if we didn't mv or hit an error, skipping nonexistent sources
if (send) {
if (errno!=EXDEV || dirtree_flagread(src, DIRTREE_SHUTUP+
DIRTREE_SYMFOLLOW*!!(FLAG(H)||FLAG(L)), TT.callback))
perror_msg("bad '%s'", src);
}
if (destdir) free(TT.destname);
}
}
void mv_main(void)
{
toys.optflags |= FLAG_d|FLAG_p|FLAG_r;
cp_main();
}
// Export cp flags into install's flag context.
static inline int cp_flag_F(void) { return FLAG_F; };
static inline int cp_flag_p(void) { return FLAG_p; };
static inline int cp_flag_v(void) { return FLAG_v; };
// Switch to install's flag context
#define FOR_install
#include <generated/flags.h>
static int install_node(struct dirtree *try)
{
try->st.st_mode = TT.i.m ? string_to_mode(TT.i.m, try->st.st_mode) : 0755;
if (TT.i.g) try->st.st_gid = TT.gid;
if (TT.i.o) try->st.st_uid = TT.uid;
// Always returns 0 because no -r
cp_node(try);
// No -r so always one level deep, so destname as set by cp_node() is correct
if (FLAG(s) && xrun((char *[]){"strip", "-p", TT.destname, 0}))
toys.exitval = 1;
return 0;
}
void install_main(void)
{
char **ss;
TT.uid = TT.i.o ? xgetuid(TT.i.o) : -1;
TT.gid = TT.i.g ? xgetgid(TT.i.g) : -1;
if (FLAG(d)) {
for (ss = toys.optargs; *ss; ss++) {
if (FLAG(v)) printf("%s\n", *ss);
if (mkpathat(AT_FDCWD, *ss, 0777, MKPATHAT_MKLAST | MKPATHAT_MAKE))
perror_msg_raw(*ss);
if (FLAG(g)||FLAG(o))
if (lchown(*ss, TT.uid, TT.gid)) perror_msg("chown '%s'", *ss);
}
return;
}
if (FLAG(D)) {
char *destname = FLAG(t) ? TT.i.t : (TT.destname = toys.optargs[toys.optc-1]);
if (mkpathat(AT_FDCWD, destname, 0777, MKPATHAT_MAKE | (FLAG(t) ? MKPATHAT_MKLAST : 0)))
perror_exit("-D '%s'", destname);
if (toys.optc == !FLAG(t)) return;
}
// Translate flags from install to cp
toys.optflags = cp_flag_F() + cp_flag_v()*!!FLAG(v)
+ cp_flag_p()*!!(FLAG(p)|FLAG(o)|FLAG(g));
TT.callback = install_node;
cp_main();
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