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/* stringutils.c - String helper functions.
* Copyright (C) 1997, 2014 Werner Koch
* Copyright (C) 2020 g10 Code GmbH
*
* This file is part of libgpg-error.
*
* libgpg-error is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* libgpg-error 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* SPDX-License-Identifier: LGPL-2.1-or-later
*/
#include <config.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <stdarg.h>
#include <errno.h>
#ifdef HAVE_STAT
# include <sys/stat.h>
#endif
#include <sys/types.h>
#ifdef HAVE_PWD_H
# include <pwd.h>
#endif
#include "gpgrt-int.h"
/* Helper for _gpgrt_fnameconcat. The additional flag WANT_ABS tells
* whether an absolute file name is requested. */
char *
_gpgrt_vfnameconcat (int want_abs, const char *first_part, va_list arg_ptr)
{
const char *argv[32];
int argc;
size_t n;
int skip = 1; /* Characters to skip from FIRST_PART. */
char *home_buffer = NULL;
char *name, *home, *p;
/* Put all args into an array because we need to scan them twice. */
n = strlen (first_part) + 1;
argc = 0;
while ((argv[argc] = va_arg (arg_ptr, const char *)))
{
n += strlen (argv[argc]) + 1;
if (argc >= DIM (argv)-1)
{
_gpg_err_set_errno (EINVAL);
return NULL;
}
argc++;
}
n++;
home = NULL;
if (*first_part == '~')
{
if (first_part[1] == '/' || !first_part[1])
{
/* This is the "~/" or "~" case. */
home_buffer = _gpgrt_getenv ("HOME");
if (!home_buffer)
home_buffer = _gpgrt_getpwdir (NULL);
home = home_buffer;
if (home && *home)
n += strlen (home);
}
else
{
/* This is the "~username/" or "~username" case. */
char *user;
user = _gpgrt_strdup (first_part+1);
if (!user)
return NULL;
p = strchr (user, '/');
if (p)
*p = 0;
skip = 1 + strlen (user);
home = home_buffer = _gpgrt_getpwdir (user);
xfree (user);
if (home)
n += strlen (home);
else
skip = 1;
}
}
name = xtrymalloc (n);
if (!name)
{
_gpgrt_free (home_buffer);
return NULL;
}
if (home)
p = stpcpy (stpcpy (name, home), first_part + skip);
else
p = stpcpy (name, first_part);
xfree (home_buffer);
home_buffer = NULL;
for (argc=0; argv[argc]; argc++)
{
/* Avoid a leading double slash if the first part was "/". */
if (!argc && name[0] == '/' && !name[1])
p = stpcpy (p, argv[argc]);
else
p = stpcpy (stpcpy (p, "/"), argv[argc]);
}
if (want_abs)
{
#ifdef HAVE_W32_SYSTEM
p = strchr (name, ':');
if (p)
p++;
else
p = name;
#else
p = name;
#endif
if (*p != '/'
#ifdef HAVE_W32_SYSTEM
&& *p != '\\'
#endif
)
{
home = _gpgrt_getcwd ();
if (!home)
{
xfree (name);
return NULL;
}
n = strlen (home) + 1 + strlen (name) + 1;
home_buffer = xtrymalloc (n);
if (!home_buffer)
{
xfree (home);
xfree (name);
return NULL;
}
if (p == name)
p = home_buffer;
else /* Windows case. */
{
memcpy (home_buffer, p, p - name + 1);
p = home_buffer + (p - name + 1);
}
/* Avoid a leading double slash if the cwd is "/". */
if (home[0] == '/' && !home[1])
strcpy (stpcpy (p, "/"), name);
else
strcpy (stpcpy (stpcpy (p, home), "/"), name);
xfree (home);
xfree (name);
name = home_buffer;
/* Let's do a simple compression to catch the common case of
* a trailing "/.". */
n = strlen (name);
if (n > 2 && name[n-2] == '/' && name[n-1] == '.')
name[n-2] = 0;
}
}
#ifdef HAVE_W32_SYSTEM
for (p=name; *p; p++)
if (*p == '\\')
*p = '/';
#endif
return name;
}
/* Construct a filename from the NULL terminated list of parts. Tilde
* expansion is done for the first argument. The caller must release
* the result using gpgrt_free; on error ERRNO is set and NULL
* returned. */
char *
_gpgrt_fnameconcat (const char *first_part, ... )
{
va_list arg_ptr;
char *result;
va_start (arg_ptr, first_part);
result = _gpgrt_vfnameconcat (0, first_part, arg_ptr);
va_end (arg_ptr);
return result;
}
/* Construct a filename from the NULL terminated list of parts. Tilde
* expansion is done for the first argument. The caller must release
* the result using gpgrt_free; on error ERRNO is set and NULL
* returned. This version returns an absolute filename. */
char *
_gpgrt_absfnameconcat (const char *first_part, ... )
{
va_list arg_ptr;
char *result;
va_start (arg_ptr, first_part);
result = _gpgrt_vfnameconcat (1, first_part, arg_ptr);
va_end (arg_ptr);
return result;
}