libexplain
1.4.D001
|
00001 /* 00002 * libexplain - a library of system-call-specific strerror replacements 00003 * Copyright (C) 2013 Peter Miller 00004 * Written by Peter Miller <pmiller@opensource.org.au> 00005 * 00006 * This program is free software; you can redistribute it and/or modify it 00007 * under the terms of the GNU Lesser General Public License as published by 00008 * the Free Software Foundation; either version 3 of the License, or (at your 00009 * option) any later version. 00010 * 00011 * This program is distributed in the hope that it will be useful, but WITHOUT 00012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 00013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 00014 * License for more details. 00015 * 00016 * You should have received a copy of the GNU Lesser General Public License 00017 * along with this program. If not, see <http://www.gnu.org/licenses/>. 00018 */ 00019 00020 #include <libexplain/ac/stdio.h> 00021 #include <libexplain/ac/string.h> 00022 00023 #include <libexplain/uid_from_pid.h> 00024 00025 00026 uid_t 00027 explain_uid_from_pid(pid_t pid) 00028 { 00029 char filename[100]; 00030 FILE *fp; 00031 00032 snprintf(filename, sizeof(filename), "/proc/%d/status", pid); 00033 fp = fopen(filename, "r"); 00034 if (!fp) 00035 return (pid_t)-1; 00036 for (;;) 00037 { 00038 int ruid; 00039 int euid; 00040 int suid; 00041 char line[200]; 00042 00043 if (!fgets(line, sizeof(line), fp)) 00044 break; 00045 if (0 != memcmp(line, "Uid:", 4)) 00046 continue; 00047 if (3 == sscanf(line + 4, "%d%d%d", &ruid, &euid, &suid)) 00048 { 00049 fclose(fp); 00050 return euid; 00051 } 00052 } 00053 fclose(fp); 00054 return (pid_t)-1; 00055 } 00056 00057 00058 /* vim: set ts=8 sw=4 et : */