Use the <pwd.h> API in getlogin_r(3).

This commit is contained in:
Jonas 'Sortie' Termansen 2013-10-02 11:02:29 +02:00
parent dd5a59e5f6
commit ca2de62ea7
1 changed files with 25 additions and 5 deletions

View File

@ -18,22 +18,42 @@
along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
unistd/getlogin_r.cpp
Get name of user logged ina t the controlling terminal.
Get name of user logged in at the controlling terminal.
*******************************************************************************/
#include <errno.h>
#include <pwd.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <unistd.h>
extern "C" int getlogin_r(char* buf, size_t size)
{
const char* env_username = getenv("USERNAME");
const char* username = env_username ? env_username : "root";
struct passwd passwd_object;
struct passwd* passwd;
int errnum = 0;
char* pwdbuf = NULL;
size_t pwdbuflen = 0;
do
{
size_t new_pwdbuflen = pwdbuflen ? 2 * pwdbuflen : 64;
char* new_pwdbuf = pwdbuf = (char*) realloc(pwdbuf, new_pwdbuflen);
if ( !new_pwdbuf )
return free(pwdbuf), -1;
pwdbuf = new_pwdbuf;
pwdbuflen = new_pwdbuflen;
} while ( (errnum = getpwuid_r(getuid(), &passwd_object, pwdbuf, pwdbuflen,
&passwd)) == ERANGE );
if ( errnum )
return free(pwdbuf), errno = errnum, -1;
const char* username = passwd->pw_name;
size_t username_len = strlen(username);
if ( size < (username_len + 1) * sizeof(char) )
return errno = ERANGE, -1;
return free(pwdbuf), errno = ERANGE, -1;
strcpy(buf, username);
return 0;
}