Radix cross Linux Package Tools

     5         kx 
     5         kx /**********************************************************************
     5         kx 
     5         kx   Copyright 2019 Andrey V.Kosteltsev
     5         kx 
     9         kx   Licensed under the Radix cross Linux License, Version 1.0 .
     5         kx   you may not use this file  except  in compliance with the License.
     5         kx   You may obtain a copy of the License at
     5         kx 
     9         kx      https://radix-linux.su/licenses/LICENSE-1.0-en_US.txt
     5         kx 
     5         kx   Unless required by applicable law or agreed to in writing, software
     5         kx   distributed under the License is distributed on an "AS IS" BASIS,
     5         kx   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
     5         kx   implied.
     5         kx 
     5         kx  **********************************************************************/
     5         kx 
     5         kx #include <config.h>
     5         kx 
     5         kx #include <stdlib.h>
     5         kx #include <stdio.h>
     5         kx #include <string.h>
     5         kx #include <errno.h>
     5         kx #include <error.h>
     5         kx #include <sys/stat.h>
     5         kx #include <sys/wait.h>
     5         kx #include <stdarg.h>
     5         kx #include <unistd.h>
     5         kx 
     5         kx #include <msglog.h>
     5         kx 
     5         kx 
     5         kx static void xexec( const char *cmd )
     5         kx {
     5         kx   char *argv[4];
     5         kx   const char *shell = getenv ("SHELL");
     5         kx 
     5         kx   if( !shell ) shell = "/bin/sh";
     5         kx 
     5         kx   argv[0] = (char *) shell;
     5         kx   argv[1] = (char *) "-c";
     5         kx   argv[2] = (char *) cmd;
     5         kx   argv[3] = NULL;
     5         kx 
     5         kx   execv( shell, argv );
     5         kx 
     5         kx   /******************************************
     5         kx     xexec() is called by child process, and
     5         kx     here child process faced to FATAL error:
     5         kx    */
     5         kx   logmsg( errlog, MSG_FATAL, "%s: Cannot exec", cmd );
     5         kx   exit( EXIT_FAILURE );
     5         kx }
     5         kx 
     5         kx static pid_t xfork( void )
     5         kx {
     5         kx   pid_t p = fork();
     5         kx 
     5         kx   if( p == (pid_t) -1 )
     5         kx   {
     5         kx     FATAL_ERROR( "Cannot %s", "fork" );
     5         kx   }
     5         kx 
     5         kx   return p;
     5         kx }
     5         kx 
     5         kx pid_t sys_exec_command( const char *cmd )
     5         kx {
     5         kx   pid_t pid = xfork();
     5         kx 
     5         kx   if( pid != 0 )
     5         kx   {
     5         kx     return pid;
     5         kx   }
     5         kx 
     5         kx   xexec( cmd );
     5         kx   return pid; /* only to avoid compilaton warning */
     5         kx }
     5         kx 
     5         kx 
     5         kx /*****************************************************************
     5         kx   sys_wait_command() - Wait for pid.
     5         kx 
     5         kx   Return values:
     5         kx   -------------
     5         kx      0  - SUCCESS
     5         kx    >=1  - status returned by child process
     5         kx     -1  - Child terminated on signal
     5         kx     -2  - Child terminated on unknown reason
     5         kx     -3  - Cannot waitpid: waitpid() retusrs -1
     5         kx 
     5         kx      Error message with SIZE length saved into *ERRMSG buffer.
     5         kx  *****************************************************************/
     5         kx int sys_wait_command( pid_t pid, char *errmsg, size_t size )
     5         kx {
     5         kx   int status;
     5         kx 
     5         kx   if( pid < 0 ) return (pid_t) -1;
     5         kx 
     5         kx   while( waitpid( pid, &status, 0 ) == -1 )
     5         kx     if( errno != EINTR )
     5         kx     {
     5         kx       if( errmsg && size ) {
     5         kx         (void)snprintf( errmsg, size, "PID %lu: Cannot %s", (unsigned long)pid, "waitpid" );
     5         kx       }
     5         kx       return (int) -3;
     5         kx     }
     5         kx 
     5         kx   if( WIFEXITED( status ) )
     5         kx   {
     5         kx     if( WEXITSTATUS (status) )
     5         kx     {
     5         kx       if( errmsg && size ) {
     5         kx         (void)snprintf( errmsg, size, "PID %lu: Child returned status %d", (unsigned long)pid, WEXITSTATUS( status ) );
     5         kx       }
     5         kx       return (int) WEXITSTATUS( status );
     5         kx     }
     5         kx   }
     5         kx   else if( WIFSIGNALED( status ) )
     5         kx   {
     5         kx     if( errmsg && size ) {
     5         kx       (void)snprintf( errmsg, size, "PID %lu: Child terminated on signal %d", (unsigned long)pid, WTERMSIG( status ) );
     5         kx     }
     5         kx     return (int) -1;
     5         kx   }
     5         kx   else
     5         kx   {
     5         kx     if( errmsg && size ) {
     5         kx       (void)snprintf( errmsg, size, "PID %lu: Child terminated on unknown reason", (unsigned long)pid );
     5         kx     }
     5         kx     return (int) -2;
     5         kx   }
     5         kx 
     5         kx   return 0;
     5         kx }