libexplain
1.4.D001
|
00001 /* 00002 * libexplain - Explain errno values returned by libc functions 00003 * Copyright (C) 2013 Peter Miller 00004 * 00005 * This program is free software; you can redistribute it and/or modify it 00006 * under the terms of the GNU Lesser General Public License as published by 00007 * the Free Software Foundation; either version 3 of the License, or (at 00008 * your option) any later version. 00009 * 00010 * This program is distributed in the hope that it will be useful, but 00011 * WITHOUT ANY WARRANTY; without even the implied warranty of 00012 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser 00013 * General Public License for more details. 00014 * 00015 * You should have received a copy of the GNU Lesser General Public License 00016 * along with this program. If not, see <http://www.gnu.org/licenses/>. 00017 */ 00018 00019 #include <libexplain/ac/errno.h> 00020 #include <libexplain/ac/sys/resource.h> 00021 00022 #include <libexplain/getpriority.h> 00023 #include <libexplain/output.h> 00024 00025 00026 int 00027 explain_getpriority_or_die(int which, int who) 00028 { 00029 int hold_errno; 00030 int result; 00031 00032 hold_errno = errno; 00033 errno = 0; 00034 /* 00035 * Since getpriority() can legitimately return the value -1, it is 00036 * necessary to clear the external variable errno prior to the call, then 00037 * check it afterward to determine if -1 is an error or a legitimate value. 00038 */ 00039 result = explain_getpriority_on_error(which, who); 00040 if (errno != 0) 00041 hold_errno = errno; 00042 if (result == -1 && hold_errno != 0) 00043 { 00044 explain_output_exit_failure(); 00045 } 00046 errno = hold_errno; 00047 return result; 00048 } 00049 00050 00051 int 00052 explain_getpriority_on_error(int which, int who) 00053 { 00054 int hold_errno; 00055 int result; 00056 00057 hold_errno = errno; 00058 errno = 0; 00059 #ifdef HAVE_GETPRIORITY 00060 result = getpriority(which, who); 00061 #else 00062 errno = ENOSYS; 00063 result = -1; 00064 #endif 00065 if (result == -1 && errno != 0) 00066 { 00067 hold_errno = errno; 00068 explain_output_error 00069 ( 00070 "%s", 00071 explain_errno_getpriority(hold_errno, which, who) 00072 ); 00073 errno = hold_errno; 00074 result = -1; 00075 } 00076 return result; 00077 } 00078 00079 00080 /* vim: set ts=8 sw=4 et : */