libgfortran/intrinsics/execute_command_line.c

   1 /* Implementation of the EXECUTE_COMMAND_LINE intrinsic.
   2    Copyright (C) 2009-2016 Free Software Foundation, Inc.
   3    Contributed by FranÃ§ois-Xavier Coudert.
   4
   5 This file is part of the GNU Fortran runtime library (libgfortran).
   6
   7 Libgfortran is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 3, or (at your option) any later
  10 version.
  11
  12 Libgfortran is distributed in the hope that it will be useful, but WITHOUT
  13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 Under Section 7 of GPL version 3, you are granted additional
  18 permissions described in the GCC Runtime Library Exception, version
  19 3.1, as published by the Free Software Foundation.
  20
  21 You should have received a copy of the GNU General Public License and
  22 a copy of the GCC Runtime Library Exception along with this program;
  23 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24 <http://www.gnu.org/licenses/>.  */
  25
  26 #include "libgfortran.h"
  27 #include <string.h>
  28 #include <stdlib.h>
  29
  30 #ifdef HAVE_UNISTD_H
  31 #include <unistd.h>
  32 #endif
  33 #ifdef  HAVE_SYS_WAIT_H
  34 #include <sys/wait.h>
  35 #endif
  36
  37
  38 enum { EXEC_SYNCHRONOUS = -2, EXEC_NOERROR = 0, EXEC_SYSTEMFAILED,
  39        EXEC_CHILDFAILED, EXEC_INVALIDCOMMAND };
  40 static const char *cmdmsg_values[] =
  41   { "",
  42     "Termination status of the command-language interpreter cannot be obtained",
  43     "Execution of child process impossible",
  44     "Invalid command line" };
  45
  46
  47
  48 static void
  49 set_cmdstat (int *cmdstat, int value)
  50 {
  51   if (cmdstat)
  52     *cmdstat = value;
  53   else if (value > EXEC_NOERROR)
  54     {
  55 #define MSGLEN 200
  56       char msg[MSGLEN] = "EXECUTE_COMMAND_LINE: ";
  57       strncat (msg, cmdmsg_values[value], MSGLEN - strlen(msg) - 1);
  58       runtime_error (msg);
  59     }
  60 }
  61
  62
  63 static void
  64 execute_command_line (const char *command, bool wait, int *exitstat,
  65                       int *cmdstat, char *cmdmsg,
  66                       gfc_charlen_type command_len,
  67                       gfc_charlen_type cmdmsg_len)
  68 {
  69   /* Transform the Fortran string to a C string.  */
  70   char *cmd = fc_strdup (command, command_len);
  71
  72   /* Flush all I/O units before executing the command.  */
  73   flush_all_units();
  74
  75 #if defined(HAVE_FORK)
  76   if (!wait)
  77     {
  78       /* Asynchronous execution.  */
  79       pid_t pid;
  80
  81       set_cmdstat (cmdstat, EXEC_NOERROR);
  82
  83       if ((pid = fork()) < 0)
  84         set_cmdstat (cmdstat, EXEC_CHILDFAILED);
  85       else if (pid == 0)
  86         {
  87           /* Child process.  */
  88           int res = system (cmd);
  89           _exit (WIFEXITED(res) ? WEXITSTATUS(res) : res);
  90         }
  91     }
  92   else
  93 #endif
  94     {
  95       /* Synchronous execution.  */
  96       int res = system (cmd);
  97
  98       if (res == -1)
  99         set_cmdstat (cmdstat, EXEC_SYSTEMFAILED);
 100 #ifndef HAVE_FORK
 101       else if (!wait)
 102         set_cmdstat (cmdstat, EXEC_SYNCHRONOUS);
 103 #endif
 104       else if (res == 127 || res == 126
 105 #if defined(WEXITSTATUS) && defined(WIFEXITED)
 106                || (WIFEXITED(res) && WEXITSTATUS(res) == 127)
 107                || (WIFEXITED(res) && WEXITSTATUS(res) == 126)
 108 #endif
 109                )
 110         /* Shell return codes 126 and 127 mean that the command line could
 111            not be executed for various reasons.  */
 112         set_cmdstat (cmdstat, EXEC_INVALIDCOMMAND);
 113       else
 114         set_cmdstat (cmdstat, EXEC_NOERROR);
 115
 116       if (res != -1)
 117         {
 118 #if defined(WEXITSTATUS) && defined(WIFEXITED)
 119           *exitstat = WIFEXITED(res) ? WEXITSTATUS(res) : res;
 120 #else
 121           *exitstat = res;
 122 #endif
 123         }
 124     }
 125
 126   free (cmd);
 127
 128   /* Now copy back to the Fortran string if needed.  */
 129   if (cmdstat && *cmdstat > EXEC_NOERROR)
 130     {
 131       if (cmdmsg)
 132         fstrcpy (cmdmsg, cmdmsg_len, cmdmsg_values[*cmdstat],
 133                 strlen (cmdmsg_values[*cmdstat]));
 134       else
 135         runtime_error ("Failure in EXECUTE_COMMAND_LINE: %s",
 136                        cmdmsg_values[*cmdstat]);
 137     }
 138 }
 139
 140
 141 extern void
 142 execute_command_line_i4 (const char *command, GFC_LOGICAL_4 *wait,
 143                          GFC_INTEGER_4 *exitstat, GFC_INTEGER_4 *cmdstat,
 144                          char *cmdmsg, gfc_charlen_type command_len,
 145                          gfc_charlen_type cmdmsg_len);
 146 export_proto(execute_command_line_i4);
 147
 148 void
 149 execute_command_line_i4 (const char *command, GFC_LOGICAL_4 *wait,
 150                          GFC_INTEGER_4 *exitstat, GFC_INTEGER_4 *cmdstat,
 151                          char *cmdmsg, gfc_charlen_type command_len,
 152                          gfc_charlen_type cmdmsg_len)
 153 {
 154   bool w = wait ? *wait : true;
 155   int estat, estat_initial, cstat;
 156
 157   if (exitstat)
 158     estat_initial = estat = *exitstat;
 159
 160   execute_command_line (command, w, &estat, cmdstat ? &cstat : NULL,
 161                         cmdmsg, command_len, cmdmsg_len);
 162
 163   if (exitstat && estat != estat_initial)
 164     *exitstat = estat;
 165   if (cmdstat)
 166     *cmdstat = cstat;
 167 }
 168
 169
 170 extern void
 171 execute_command_line_i8 (const char *command, GFC_LOGICAL_8 *wait,
 172                          GFC_INTEGER_8 *exitstat, GFC_INTEGER_8 *cmdstat,
 173                          char *cmdmsg, gfc_charlen_type command_len,
 174                          gfc_charlen_type cmdmsg_len);
 175 export_proto(execute_command_line_i8);
 176
 177 void
 178 execute_command_line_i8 (const char *command, GFC_LOGICAL_8 *wait,
 179                          GFC_INTEGER_8 *exitstat, GFC_INTEGER_8 *cmdstat,
 180                          char *cmdmsg, gfc_charlen_type command_len,
 181                          gfc_charlen_type cmdmsg_len)
 182 {
 183   bool w = wait ? *wait : true;
 184   int estat, estat_initial, cstat;
 185
 186   if (exitstat)
 187     estat_initial = estat = *exitstat;
 188
 189   execute_command_line (command, w, &estat, cmdstat ? &cstat : NULL,
 190                         cmdmsg, command_len, cmdmsg_len);
 191
 192   if (exitstat && estat != estat_initial)
 193     *exitstat = estat;
 194   if (cmdstat)
 195     *cmdstat = cstat;
 196 }