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mc/lib/utilunix.c

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/*
Various utilities - Unix variants
Copyright (C) 1994-2024
Free Software Foundation, Inc.
Written by:
Miguel de Icaza, 1994, 1995, 1996
Janne Kukonlehto, 1994, 1995, 1996
Dugan Porter, 1994, 1995, 1996
Jakub Jelinek, 1994, 1995, 1996
Mauricio Plaza, 1994, 1995, 1996
Andrew Borodin <aborodin@vmail.ru> 2010-2022
The mc_realpath routine is mostly from uClibc package, written
by Rick Sladkey <jrs@world.std.com>
This file is part of the Midnight Commander.
The Midnight Commander is free software: you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation, either version 3 of the License,
or (at your option) any later version.
The Midnight Commander is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/** \file utilunix.c
* \brief Source: various utilities - Unix variant
*/
#include <config.h>
#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#include <sys/types.h>
#include <sys/stat.h>
#ifdef HAVE_SYS_SELECT_H
#include <sys/select.h>
#endif
#include <sys/wait.h>
#include <pwd.h>
#include <grp.h>
#include "lib/global.h"
#include "lib/unixcompat.h"
#include "lib/vfs/vfs.h" /* VFS_ENCODING_PREFIX */
#include "lib/strutil.h" /* str_move() */
#include "lib/util.h"
#include "lib/widget.h" /* message() */
#include "lib/vfs/xdirentry.h"
#ifdef HAVE_CHARSET
#include "lib/charsets.h"
#endif
#include "utilunix.h"
/*** global variables ****************************************************************************/
struct sigaction startup_handler;
/*** file scope macro definitions ****************************************************************/
#define UID_CACHE_SIZE 200
#define GID_CACHE_SIZE 30
/*** file scope type declarations ****************************************************************/
typedef struct
{
int index;
char *string;
} int_cache;
typedef enum
{
FORK_ERROR = -1,
FORK_CHILD,
FORK_PARENT,
} my_fork_state_t;
typedef struct
{
struct sigaction intr;
struct sigaction quit;
struct sigaction stop;
} my_system_sigactions_t;
/*** forward declarations (file scope functions) *************************************************/
/*** file scope variables ************************************************************************/
static int_cache uid_cache[UID_CACHE_SIZE];
static int_cache gid_cache[GID_CACHE_SIZE];
/* --------------------------------------------------------------------------------------------- */
/*** file scope functions ************************************************************************/
/* --------------------------------------------------------------------------------------------- */
static char *
i_cache_match (int id, int_cache * cache, int size)
{
int i;
for (i = 0; i < size; i++)
if (cache[i].index == id)
return cache[i].string;
return 0;
}
/* --------------------------------------------------------------------------------------------- */
static void
i_cache_add (int id, int_cache * cache, int size, char *text, int *last)
{
g_free (cache[*last].string);
cache[*last].string = g_strdup (text);
cache[*last].index = id;
*last = ((*last) + 1) % size;
}
/* --------------------------------------------------------------------------------------------- */
static my_fork_state_t
my_fork (void)
{
pid_t pid;
pid = fork ();
if (pid < 0)
{
fprintf (stderr, "\n\nfork () = -1\n");
return FORK_ERROR;
}
if (pid == 0)
return FORK_CHILD;
while (TRUE)
{
int status = 0;
if (waitpid (pid, &status, 0) > 0)
return WEXITSTATUS (status) == 0 ? FORK_PARENT : FORK_ERROR;
if (errno != EINTR)
return FORK_ERROR;
}
}
/* --------------------------------------------------------------------------------------------- */
static void
my_system__save_sigaction_handlers (my_system_sigactions_t * sigactions)
{
struct sigaction ignore;
memset (&ignore, 0, sizeof (ignore));
ignore.sa_handler = SIG_IGN;
sigemptyset (&ignore.sa_mask);
sigaction (SIGINT, &ignore, &sigactions->intr);
sigaction (SIGQUIT, &ignore, &sigactions->quit);
/* Restore the original SIGTSTP handler, we don't want ncurses' */
/* handler messing the screen after the SIGCONT */
sigaction (SIGTSTP, &startup_handler, &sigactions->stop);
}
/* --------------------------------------------------------------------------------------------- */
static void
my_system__restore_sigaction_handlers (my_system_sigactions_t * sigactions)
{
sigaction (SIGINT, &sigactions->intr, NULL);
sigaction (SIGQUIT, &sigactions->quit, NULL);
sigaction (SIGTSTP, &sigactions->stop, NULL);
}
/* --------------------------------------------------------------------------------------------- */
static GPtrArray *
my_system_make_arg_array (int flags, const char *shell, char **execute_name)
{
GPtrArray *args_array;
args_array = g_ptr_array_new ();
if ((flags & EXECUTE_AS_SHELL) != 0)
{
g_ptr_array_add (args_array, (gpointer) shell);
g_ptr_array_add (args_array, (gpointer) "-c");
*execute_name = g_strdup (shell);
}
else
{
char *shell_token;
shell_token = shell != NULL ? strchr (shell, ' ') : NULL;
if (shell_token == NULL)
*execute_name = g_strdup (shell);
else
*execute_name = g_strndup (shell, (gsize) (shell_token - shell));
g_ptr_array_add (args_array, (gpointer) shell);
}
return args_array;
}
/* --------------------------------------------------------------------------------------------- */
static void
mc_pread_stream (mc_pipe_stream_t * ps, const fd_set * fds)
{
size_t buf_len;
ssize_t read_len;
if (!FD_ISSET (ps->fd, fds))
{
ps->len = MC_PIPE_STREAM_UNREAD;
return;
}
buf_len = (size_t) ps->len;
if (buf_len >= MC_PIPE_BUFSIZE)
buf_len = ps->null_term ? MC_PIPE_BUFSIZE - 1 : MC_PIPE_BUFSIZE;
do
{
read_len = read (ps->fd, ps->buf, buf_len);
}
while (read_len < 0 && errno == EINTR);
if (read_len < 0)
{
/* reading error */
ps->len = MC_PIPE_ERROR_READ;
ps->error = errno;
}
else if (read_len == 0)
/* EOF */
ps->len = MC_PIPE_STREAM_EOF;
else
{
/* success */
ps->len = read_len;
if (ps->null_term)
ps->buf[(size_t) ps->len] = '\0';
}
ps->pos = 0;
}
/* --------------------------------------------------------------------------------------------- */
/*** public functions ****************************************************************************/
/* --------------------------------------------------------------------------------------------- */
const char *
get_owner (uid_t uid)
{
struct passwd *pwd;
char *name;
static uid_t uid_last;
name = i_cache_match ((int) uid, uid_cache, UID_CACHE_SIZE);
if (name != NULL)
return name;
pwd = getpwuid (uid);
if (pwd != NULL)
{
i_cache_add ((int) uid, uid_cache, UID_CACHE_SIZE, pwd->pw_name, (int *) &uid_last);
return pwd->pw_name;
}
else
{
static char ibuf[10];
g_snprintf (ibuf, sizeof (ibuf), "%d", (int) uid);
return ibuf;
}
}
/* --------------------------------------------------------------------------------------------- */
const char *
get_group (gid_t gid)
{
struct group *grp;
char *name;
static gid_t gid_last;
name = i_cache_match ((int) gid, gid_cache, GID_CACHE_SIZE);
if (name != NULL)
return name;
grp = getgrgid (gid);
if (grp != NULL)
{
i_cache_add ((int) gid, gid_cache, GID_CACHE_SIZE, grp->gr_name, (int *) &gid_last);
return grp->gr_name;
}
else
{
static char gbuf[10];
g_snprintf (gbuf, sizeof (gbuf), "%d", (int) gid);
return gbuf;
}
}
/* --------------------------------------------------------------------------------------------- */
/* Since ncurses uses a handler that automatically refreshes the */
/* screen after a SIGCONT, and we don't want this behavior when */
/* spawning a child, we save the original handler here */
void
save_stop_handler (void)
{
sigaction (SIGTSTP, NULL, &startup_handler);
}
/* --------------------------------------------------------------------------------------------- */
/**
* Wrapper for _exit() system call.
* The _exit() function has gcc's attribute 'noreturn', and this is reason why we can't
* mock the call.
*
* @param status exit code
*/
void
/* __attribute__ ((noreturn)) */
my_exit (int status)
{
_exit (status);
}
/* --------------------------------------------------------------------------------------------- */
/**
* Call external programs.
*
* @parameter flags addition conditions for running external programs.
* @parameter shell shell (if flags contain EXECUTE_AS_SHELL), command to run otherwise.
* Shell (or command) will be found in paths described in PATH variable
* (if shell parameter doesn't begin from path delimiter)
* @parameter command Command for shell (or first parameter for command, if flags contain EXECUTE_AS_SHELL)
* @return 0 if successful, -1 otherwise
*/
int
my_system (int flags, const char *shell, const char *command)
{
return my_systeml (flags, shell, command, NULL);
}
/* --------------------------------------------------------------------------------------------- */
/**
* Call external programs with various parameters number.
*
* @parameter flags addition conditions for running external programs.
* @parameter shell shell (if flags contain EXECUTE_AS_SHELL), command to run otherwise.
* Shell (or command) will be found in paths described in PATH variable
* (if shell parameter doesn't begin from path delimiter)
* @parameter ... Command for shell with addition parameters for shell
* (or parameters for command, if flags contain EXECUTE_AS_SHELL).
* Should be NULL terminated.
* @return 0 if successful, -1 otherwise
*/
int
my_systeml (int flags, const char *shell, ...)
{
GPtrArray *args_array;
int status = 0;
va_list vargs;
char *one_arg;
args_array = g_ptr_array_new ();
va_start (vargs, shell);
while ((one_arg = va_arg (vargs, char *)) != NULL)
g_ptr_array_add (args_array, one_arg);
va_end (vargs);
g_ptr_array_add (args_array, NULL);
status = my_systemv_flags (flags, shell, (char *const *) args_array->pdata);
g_ptr_array_free (args_array, TRUE);
return status;
}
/* --------------------------------------------------------------------------------------------- */
/**
* Call external programs with array of strings as parameters.
*
* @parameter command command to run. Command will be found in paths described in PATH variable
* (if command parameter doesn't begin from path delimiter)
* @parameter argv Array of strings (NULL-terminated) with parameters for command
* @return 0 if successful, -1 otherwise
*/
int
my_systemv (const char *command, char *const argv[])
{
my_fork_state_t fork_state;
int status = 0;
my_system_sigactions_t sigactions;
my_system__save_sigaction_handlers (&sigactions);
fork_state = my_fork ();
switch (fork_state)
{
case FORK_ERROR:
status = -1;
break;
case FORK_CHILD:
{
signal (SIGINT, SIG_DFL);
signal (SIGQUIT, SIG_DFL);
signal (SIGTSTP, SIG_DFL);
signal (SIGCHLD, SIG_DFL);
execvp (command, argv);
my_exit (127); /* Exec error */
}
MC_FALLTHROUGH;
/* no break here, or unreachable-code warning by no returning my_exit() */
default:
status = 0;
break;
}
my_system__restore_sigaction_handlers (&sigactions);
return status;
}
/* --------------------------------------------------------------------------------------------- */
/**
* Call external programs with flags and with array of strings as parameters.
*
* @parameter flags addition conditions for running external programs.
* @parameter command shell (if flags contain EXECUTE_AS_SHELL), command to run otherwise.
* Shell (or command) will be found in paths described in PATH variable
* (if shell parameter doesn't begin from path delimiter)
* @parameter argv Array of strings (NULL-terminated) with parameters for command
* @return 0 if successful, -1 otherwise
*/
int
my_systemv_flags (int flags, const char *command, char *const argv[])
{
char *execute_name = NULL;
GPtrArray *args_array;
int status = 0;
args_array = my_system_make_arg_array (flags, command, &execute_name);
for (; argv != NULL && *argv != NULL; argv++)
g_ptr_array_add (args_array, *argv);
g_ptr_array_add (args_array, NULL);
status = my_systemv (execute_name, (char *const *) args_array->pdata);
g_free (execute_name);
g_ptr_array_free (args_array, TRUE);
return status;
}
/* --------------------------------------------------------------------------------------------- */
/**
* Create pipe and run child process.
*
* @parameter command command line of child process
* @parameter read_out do or don't read the stdout of child process
* @parameter read_err do or don't read the stderr of child process
* @parameter error contains pointer to object to handle error code and message
*
* @return newly created object of mc_pipe_t class in success, NULL otherwise
*/
mc_pipe_t *
mc_popen (const char *command, gboolean read_out, gboolean read_err, GError ** error)
{
mc_pipe_t *p;
const char *const argv[] = { "/bin/sh", "sh", "-c", command, NULL };
p = g_try_new (mc_pipe_t, 1);
if (p == NULL)
{
mc_replace_error (error, MC_PIPE_ERROR_CREATE_PIPE, "%s",
_("Cannot create pipe descriptor"));
goto ret_err;
}
p->out.fd = -1;
p->err.fd = -1;
if (!g_spawn_async_with_pipes
(NULL, (gchar **) argv, NULL, G_SPAWN_DO_NOT_REAP_CHILD | G_SPAWN_FILE_AND_ARGV_ZERO, NULL,
NULL, &p->child_pid, NULL, read_out ? &p->out.fd : NULL, read_err ? &p->err.fd : NULL,
error))
{
mc_replace_error (error, MC_PIPE_ERROR_CREATE_PIPE_STREAM, "%s",
_("Cannot create pipe streams"));
goto ret_err;
}
p->out.buf[0] = '\0';
p->out.len = MC_PIPE_BUFSIZE;
p->out.null_term = FALSE;
p->err.buf[0] = '\0';
p->err.len = MC_PIPE_BUFSIZE;
p->err.null_term = FALSE;
return p;
ret_err:
g_free (p);
return NULL;
}
/* --------------------------------------------------------------------------------------------- */
/**
* Read stdout and stderr of pipe asynchronously.
*
* @parameter p pipe descriptor
*
* The lengths of read data contain in p->out.len and p->err.len.
*
* Before read, p->xxx.len is an input. It defines the number of data to read.
* Should not be greater than MC_PIPE_BUFSIZE.
*
* After read, p->xxx.len is an output and contains the following:
* p->xxx.len > 0: an actual length of read data stored in p->xxx.buf;
* p->xxx.len == MC_PIPE_STREAM_EOF: EOF of stream p->xxx;
* p->xxx.len == MC_PIPE_STREAM_UNREAD: stream p->xxx was not read;
* p->xxx.len == MC_PIPE_ERROR_READ: reading error, and p->xxx.errno is set appropriately.
*
* @parameter error contains pointer to object to handle error code and message
*/
void
mc_pread (mc_pipe_t * p, GError ** error)
{
gboolean read_out, read_err;
fd_set fds;
int maxfd = 0;
int res;
if (error != NULL)
*error = NULL;
read_out = p->out.fd >= 0;
read_err = p->err.fd >= 0;
if (!read_out && !read_err)
{
p->out.len = MC_PIPE_STREAM_UNREAD;
p->err.len = MC_PIPE_STREAM_UNREAD;
return;
}
FD_ZERO (&fds);
if (read_out)
{
FD_SET (p->out.fd, &fds);
maxfd = p->out.fd;
}
if (read_err)
{
FD_SET (p->err.fd, &fds);
maxfd = MAX (maxfd, p->err.fd);
}
/* no timeout */
res = select (maxfd + 1, &fds, NULL, NULL, NULL);
if (res < 0 && errno != EINTR)
{
mc_propagate_error (error, MC_PIPE_ERROR_READ,
_
("Unexpected error in select() reading data from a child process:\n%s"),
unix_error_string (errno));
return;
}
if (read_out)
mc_pread_stream (&p->out, &fds);
else
p->out.len = MC_PIPE_STREAM_UNREAD;
if (read_err)
mc_pread_stream (&p->err, &fds);
else
p->err.len = MC_PIPE_STREAM_UNREAD;
}
/* --------------------------------------------------------------------------------------------- */
/**
* Reads a line from @stream. Reading stops after an EOL or a newline. If a newline is read,
* it is appended to the line.
*
* @stream mc_pipe_stream_t object
*
* @return newly created GString or NULL in case of EOL;
*/
GString *
mc_pstream_get_string (mc_pipe_stream_t * ps)
{
char *s;
size_t size, i;
gboolean escape = FALSE;
g_return_val_if_fail (ps != NULL, NULL);
if (ps->len < 0)
return NULL;
size = ps->len - ps->pos;
if (size == 0)
return NULL;
s = ps->buf + ps->pos;
if (s[0] == '\0')
return NULL;
/* find '\0' or unescaped '\n' */
for (i = 0; i < size && !(s[i] == '\0' || (s[i] == '\n' && !escape)); i++)
escape = s[i] == '\\' ? !escape : FALSE;
if (i != size && s[i] == '\n')
i++;
ps->pos += i;
return g_string_new_len (s, i);
}
/* --------------------------------------------------------------------------------------------- */
/**
* Close pipe and destroy pipe descriptor.
*
* @parameter p pipe descriptor
* @parameter error contains pointer to object to handle error code and message
*/
void
mc_pclose (mc_pipe_t * p, GError ** error)
{
int res;
if (p == NULL)
{
mc_replace_error (error, MC_PIPE_ERROR_READ, "%s",
_("Cannot close pipe descriptor (p == NULL)"));
return;
}
if (p->out.fd >= 0)
res = close (p->out.fd);
if (p->err.fd >= 0)
res = close (p->err.fd);
do
{
int status;
res = waitpid (p->child_pid, &status, 0);
}
while (res < 0 && errno == EINTR);
if (res < 0)
mc_replace_error (error, MC_PIPE_ERROR_READ, _("Unexpected error in waitpid():\n%s"),
unix_error_string (errno));
g_free (p);
}
/* --------------------------------------------------------------------------------------------- */
/**
* Perform tilde expansion if possible.
*
* @param directory pointer to the path
*
* @return newly allocated string, even if it's unchanged.
*/
char *
tilde_expand (const char *directory)
{
struct passwd *passwd;
const char *p, *q;
if (*directory != '~')
return g_strdup (directory);
p = directory + 1;
/* d = "~" or d = "~/" */
if (*p == '\0' || IS_PATH_SEP (*p))
{
passwd = getpwuid (geteuid ());
q = IS_PATH_SEP (*p) ? p + 1 : "";
}
else
{
q = strchr (p, PATH_SEP);
if (q == NULL)
passwd = getpwnam (p);
else
{
char *name;
name = g_strndup (p, q - p);
passwd = getpwnam (name);
q++;
g_free (name);
}
}
/* If we can't figure the user name, leave tilde unexpanded */
if (passwd == NULL)
return g_strdup (directory);
return g_strconcat (passwd->pw_dir, PATH_SEP_STR, q, (char *) NULL);
}
/* --------------------------------------------------------------------------------------------- */
/**
* Canonicalize path.
*
* @param path path to file
* @param flags canonicalization flags
*
* All modifications of @path are made in place.
* Well formed UNC paths are modified only in the local part.
*/
void
canonicalize_pathname_custom (char *path, canon_path_flags_t flags)
{
char *p, *s;
char *lpath = path; /* path without leading UNC part */
const size_t url_delim_len = strlen (VFS_PATH_URL_DELIMITER);
/* Detect and preserve UNC paths: //server/... */
if ((flags & CANON_PATH_GUARDUNC) != 0 && IS_PATH_SEP (path[0]) && IS_PATH_SEP (path[1]))
{
for (p = path + 2; p[0] != '\0' && !IS_PATH_SEP (p[0]); p++)
;
if (IS_PATH_SEP (p[0]) && p > path + 2)
lpath = p;
}
if (lpath[0] == '\0' || lpath[1] == '\0')
return;
if ((flags & CANON_PATH_JOINSLASHES) != 0)
{
/* Collapse multiple slashes */
for (p = lpath; *p != '\0'; p++)
if (IS_PATH_SEP (p[0]) && IS_PATH_SEP (p[1]) && (p == lpath || *(p - 1) != ':'))
{
s = p + 1;
while (IS_PATH_SEP (*(++s)))
;
str_move (p + 1, s);
}
/* Collapse "/./" -> "/" */
for (p = lpath; *p != '\0';)
if (IS_PATH_SEP (p[0]) && p[1] == '.' && IS_PATH_SEP (p[2]))
str_move (p, p + 2);
else
p++;
}
if ((flags & CANON_PATH_REMSLASHDOTS) != 0)
{
size_t len;
/* Remove trailing slashes */
for (p = lpath + strlen (lpath) - 1; p > lpath && IS_PATH_SEP (*p); p--)
{
if (p >= lpath + url_delim_len - 1
&& strncmp (p - url_delim_len + 1, VFS_PATH_URL_DELIMITER, url_delim_len) == 0)
break;
*p = '\0';
}
/* Remove leading "./" */
if (lpath[0] == '.' && IS_PATH_SEP (lpath[1]))
{
if (lpath[2] == '\0')
{
lpath[1] = '\0';
return;
}
str_move (lpath, lpath + 2);
}
/* Remove trailing "/" or "/." */
len = strlen (lpath);
if (len < 2)
return;
if (IS_PATH_SEP (lpath[len - 1])
&& (len < url_delim_len
|| strncmp (lpath + len - url_delim_len, VFS_PATH_URL_DELIMITER,
url_delim_len) != 0))
lpath[len - 1] = '\0';
else if (lpath[len - 1] == '.' && IS_PATH_SEP (lpath[len - 2]))
{
if (len == 2)
{
lpath[1] = '\0';
return;
}
lpath[len - 2] = '\0';
}
}
/* Collapse "/.." with the previous part of path */
if ((flags & CANON_PATH_REMDOUBLEDOTS) != 0)
{
#ifdef HAVE_CHARSET
const size_t enc_prefix_len = strlen (VFS_ENCODING_PREFIX);
#endif /* HAVE_CHARSET */
for (p = lpath; p[0] != '\0' && p[1] != '\0' && p[2] != '\0';)
{
if (!IS_PATH_SEP (p[0]) || p[1] != '.' || p[2] != '.'
|| (!IS_PATH_SEP (p[3]) && p[3] != '\0'))
{
p++;
continue;
}
/* search for the previous token */
s = p - 1;
if (s >= lpath + url_delim_len - 2
&& strncmp (s - url_delim_len + 2, VFS_PATH_URL_DELIMITER, url_delim_len) == 0)
{
s -= (url_delim_len - 2);
while (s >= lpath && !IS_PATH_SEP (*s--))
;
}
while (s >= lpath)
{
if (s - url_delim_len > lpath
&& strncmp (s - url_delim_len, VFS_PATH_URL_DELIMITER, url_delim_len) == 0)
{
char *vfs_prefix = s - url_delim_len;
vfs_class *vclass;
while (vfs_prefix > lpath && !IS_PATH_SEP (*--vfs_prefix))
;
if (IS_PATH_SEP (*vfs_prefix))
vfs_prefix++;
*(s - url_delim_len) = '\0';
vclass = vfs_prefix_to_class (vfs_prefix);
*(s - url_delim_len) = *VFS_PATH_URL_DELIMITER;
if (vclass != NULL && (vclass->flags & VFSF_REMOTE) != 0)
{
s = vfs_prefix;
continue;
}
}
if (IS_PATH_SEP (*s))
break;
s--;
}
s++;
/* If the previous token is "..", we cannot collapse it */
if (s[0] == '.' && s[1] == '.' && s + 2 == p)
{
p += 3;
continue;
}
if (p[3] != '\0')
{
if (s == lpath && IS_PATH_SEP (*s))
{
/* "/../foo" -> "/foo" */
str_move (s + 1, p + 4);
}
else
{
/* "token/../foo" -> "foo" */
#ifdef HAVE_CHARSET
if ((strncmp (s, VFS_ENCODING_PREFIX, enc_prefix_len) == 0)
&& (is_supported_encoding (s + enc_prefix_len)))
/* special case: remove encoding */
str_move (s, p + 1);
else
#endif /* HAVE_CHARSET */
str_move (s, p + 4);
}
p = s > lpath ? s - 1 : s;
continue;
}
/* trailing ".." */
if (s == lpath)
{
/* "token/.." -> "." */
if (!IS_PATH_SEP (lpath[0]))
lpath[0] = '.';
lpath[1] = '\0';
}
else
{
/* "foo/token/.." -> "foo" */
if (s == lpath + 1)
s[0] = '\0';
#ifdef HAVE_CHARSET
else if ((strncmp (s, VFS_ENCODING_PREFIX, enc_prefix_len) == 0)
&& (is_supported_encoding (s + enc_prefix_len)))
{
/* special case: remove encoding */
s[0] = '.';
s[1] = '.';
s[2] = '\0';
/* search for the previous token */
/* IS_PATH_SEP (s[-1]) */
for (p = s - 1; p >= lpath && !IS_PATH_SEP (*p); p--)
;
if (p >= lpath)
continue;
}
#endif /* HAVE_CHARSET */
else
{
if (s >= lpath + url_delim_len
&& strncmp (s - url_delim_len, VFS_PATH_URL_DELIMITER, url_delim_len) == 0)
*s = '\0';
else
s[-1] = '\0';
}
}
break;
}
}
}
/* --------------------------------------------------------------------------------------------- */
char *
mc_realpath (const char *path, char *resolved_path)
{
#ifdef HAVE_CHARSET
const char *p = path;
gboolean absolute_path = FALSE;
if (IS_PATH_SEP (*p))
{
absolute_path = TRUE;
p++;
}
/* ignore encoding: skip "#enc:" */
if (g_str_has_prefix (p, VFS_ENCODING_PREFIX))
{
p += strlen (VFS_ENCODING_PREFIX);
p = strchr (p, PATH_SEP);
if (p != NULL)
{
if (!absolute_path && p[1] != '\0')
p++;
path = p;
}
}
#endif /* HAVE_CHARSET */
#ifdef HAVE_REALPATH
return realpath (path, resolved_path);
#else
{
char copy_path[PATH_MAX];
char got_path[PATH_MAX];
char *new_path = got_path;
char *max_path;
#ifdef S_IFLNK
char link_path[PATH_MAX];
int readlinks = 0;
int n;
#endif /* S_IFLNK */
/* Make a copy of the source path since we may need to modify it. */
if (strlen (path) >= PATH_MAX - 2)
{
errno = ENAMETOOLONG;
return NULL;
}
strcpy (copy_path, path);
path = copy_path;
max_path = copy_path + PATH_MAX - 2;
/* If it's a relative pathname use getwd for starters. */
if (!IS_PATH_SEP (*path))
{
new_path = g_get_current_dir ();
if (new_path == NULL)
strcpy (got_path, "");
else
{
g_snprintf (got_path, sizeof (got_path), "%s", new_path);
g_free (new_path);
new_path = got_path;
}
new_path += strlen (got_path);
if (!IS_PATH_SEP (new_path[-1]))
*new_path++ = PATH_SEP;
}
else
{
*new_path++ = PATH_SEP;
path++;
}
/* Expand each slash-separated pathname component. */
while (*path != '\0')
{
/* Ignore stray "/". */
if (IS_PATH_SEP (*path))
{
path++;
continue;
}
if (*path == '.')
{
/* Ignore ".". */
if (path[1] == '\0' || IS_PATH_SEP (path[1]))
{
path++;
continue;
}
if (path[1] == '.')
{
if (path[2] == '\0' || IS_PATH_SEP (path[2]))
{
path += 2;
/* Ignore ".." at root. */
if (new_path == got_path + 1)
continue;
/* Handle ".." by backing up. */
while (!IS_PATH_SEP ((--new_path)[-1]))
;
continue;
}
}
}
/* Safely copy the next pathname component. */
while (*path != '\0' && !IS_PATH_SEP (*path))
{
if (path > max_path)
{
errno = ENAMETOOLONG;
return NULL;
}
*new_path++ = *path++;
}
#ifdef S_IFLNK
/* Protect against infinite loops. */
if (readlinks++ > MAXSYMLINKS)
{
errno = ELOOP;
return NULL;
}
/* See if latest pathname component is a symlink. */
*new_path = '\0';
n = readlink (got_path, link_path, PATH_MAX - 1);
if (n < 0)
{
/* EINVAL means the file exists but isn't a symlink. */
if (errno != EINVAL)
{
/* Make sure it's null terminated. */
*new_path = '\0';
strcpy (resolved_path, got_path);
return NULL;
}
}
else
{
/* Note: readlink doesn't add the null byte. */
link_path[n] = '\0';
if (IS_PATH_SEP (*link_path))
/* Start over for an absolute symlink. */
new_path = got_path;
else
/* Otherwise back up over this component. */
while (!IS_PATH_SEP (*(--new_path)))
;
/* Safe sex check. */
if (strlen (path) + n >= PATH_MAX - 2)
{
errno = ENAMETOOLONG;
return NULL;
}
/* Insert symlink contents into path. */
strcat (link_path, path);
strcpy (copy_path, link_path);
path = copy_path;
}
#endif /* S_IFLNK */
*new_path++ = PATH_SEP;
}
/* Delete trailing slash but don't whomp a lone slash. */
if (new_path != got_path + 1 && IS_PATH_SEP (new_path[-1]))
new_path--;
/* Make sure it's null terminated. */
*new_path = '\0';
strcpy (resolved_path, got_path);
return resolved_path;
}
#endif /* HAVE_REALPATH */
}
/* --------------------------------------------------------------------------------------------- */
/**
* Return the index of the permissions triplet
*
*/
int
get_user_permissions (struct stat *st)
{
static gboolean initialized = FALSE;
static gid_t *groups;
static int ngroups;
static uid_t uid;
int i;
if (!initialized)
{
uid = geteuid ();
ngroups = getgroups (0, NULL);
if (ngroups == -1)
ngroups = 0; /* ignore errors */
/* allocate space for one element in addition to what
* will be filled by getgroups(). */
groups = g_new (gid_t, ngroups + 1);
if (ngroups != 0)
{
ngroups = getgroups (ngroups, groups);
if (ngroups == -1)
ngroups = 0; /* ignore errors */
}
/* getgroups() may or may not return the effective group ID,
* so we always include it at the end of the list. */
groups[ngroups++] = getegid ();
initialized = TRUE;
}
if (st->st_uid == uid || uid == 0)
return 0;
for (i = 0; i < ngroups; i++)
if (st->st_gid == groups[i])
return 1;
return 2;
}
/* --------------------------------------------------------------------------------------------- */
/**
* Build filename from arguments.
* Like to g_build_filename(), but respect VFS_PATH_URL_DELIMITER
*/
char *
mc_build_filenamev (const char *first_element, va_list args)
{
gboolean absolute;
const char *element = first_element;
GString *path;
char *ret;
if (element == NULL)
return NULL;
path = g_string_new ("");
absolute = IS_PATH_SEP (*first_element);
do
{
if (*element == '\0')
element = va_arg (args, char *);
else
{
char *tmp_element;
size_t len;
const char *start;
tmp_element = g_strdup (element);
element = va_arg (args, char *);
canonicalize_pathname (tmp_element);
len = strlen (tmp_element);
start = IS_PATH_SEP (tmp_element[0]) ? tmp_element + 1 : tmp_element;
g_string_append (path, start);
if (!IS_PATH_SEP (tmp_element[len - 1]) && element != NULL)
g_string_append_c (path, PATH_SEP);
g_free (tmp_element);
}
}
while (element != NULL);
if (absolute)
g_string_prepend_c (path, PATH_SEP);
ret = g_string_free (path, FALSE);
canonicalize_pathname (ret);
return ret;
}
/* --------------------------------------------------------------------------------------------- */
/**
* Build filename from arguments.
* Like to g_build_filename(), but respect VFS_PATH_URL_DELIMITER
*/
char *
mc_build_filename (const char *first_element, ...)
{
va_list args;
char *ret;
if (first_element == NULL)
return NULL;
va_start (args, first_element);
ret = mc_build_filenamev (first_element, args);
va_end (args);
return ret;
}
/* --------------------------------------------------------------------------------------------- */
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