libgfortran/intrinsics/execute_command_line.c

   1 /* Implementation of the EXECUTE_COMMAND_LINE intrinsic.
   2    Copyright (C) 2009-2018 Free Software Foundation, Inc.
   3    Contributed by François-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
  29 #ifdef HAVE_UNISTD_H
  30 #include <unistd.h>
  31 #endif
  32 #ifdef  HAVE_SYS_WAIT_H
  33 #include <sys/wait.h>
  34 #endif
  35
  36
  37 enum { EXEC_SYNCHRONOUS = -2, EXEC_NOERROR = 0, EXEC_SYSTEMFAILED,
  38        EXEC_CHILDFAILED, EXEC_INVALIDCOMMAND };
  39 static const char *cmdmsg_values[] =
  40   { "",
  41     "Termination status of the command-language interpreter cannot be obtained",
  42     "Execution of child process impossible",
  43     "Invalid command line" };
  44
  45
  46
  47 static void
  48 set_cmdstat (int *cmdstat, int value)
  49 {
  50   if (cmdstat)
  51     *cmdstat = value;
  52   else if (value > EXEC_NOERROR)
  53     {
  54 #define MSGLEN 200
  55       char msg[MSGLEN] = "EXECUTE_COMMAND_LINE: ";
  56       strncat (msg, cmdmsg_values[value], MSGLEN - strlen(msg) - 1);
  57       runtime_error ("%s", msg);
  58     }
  59 }
  60
  61
  62 static void
  63 execute_command_line (const char *command, bool wait, int *exitstat,
  64                       int *cmdstat, char *cmdmsg,
  65                       gfc_charlen_type command_len,
  66                       gfc_charlen_type cmdmsg_len)
  67 {
  68   /* Transform the Fortran string to a C string.  */
  69   char *cmd = fc_strdup (command, command_len);
  70
  71   /* Flush all I/O units before executing the command.  */
  72   flush_all_units();
  73
  74 #if defined(HAVE_FORK)
  75   if (!wait)
  76     {
  77       /* Asynchronous execution.  */
  78       pid_t pid;
  79
  80       set_cmdstat (cmdstat, EXEC_NOERROR);
  81
  82       if ((pid = fork()) < 0)
  83         set_cmdstat (cmdstat, EXEC_CHILDFAILED);
  84       else if (pid == 0)
  85         {
  86           /* Child process.  */
  87           int res = system (cmd);
  88           _exit (WIFEXITED(res) ? WEXITSTATUS(res) : res);
  89         }
  90     }
  91   else
  92 #endif
  93     {
  94       /* Synchronous execution.  */
  95       int res = system (cmd);
  96
  97       if (res == -1)
  98         set_cmdstat (cmdstat, EXEC_SYSTEMFAILED);
  99 #ifndef HAVE_FORK
 100       else if (!wait)
 101         set_cmdstat (cmdstat, EXEC_SYNCHRONOUS);
 102 #endif
 103       else if (res == 127 || res == 126
 104 #if defined(WEXITSTATUS) && defined(WIFEXITED)
 105                || (WIFEXITED(res) && WEXITSTATUS(res) == 127)
 106                || (WIFEXITED(res) && WEXITSTATUS(res) == 126)
 107 #endif
 108                )
 109         /* Shell return codes 126 and 127 mean that the command line could
 110            not be executed for various reasons.  */
 111         set_cmdstat (cmdstat, EXEC_INVALIDCOMMAND);
 112       else
 113         set_cmdstat (cmdstat, EXEC_NOERROR);
 114
 115       if (res != -1)
 116         {
 117 #if defined(WEXITSTATUS) && defined(WIFEXITED)
 118           *exitstat = WIFEXITED(res) ? WEXITSTATUS(res) : res;
 119 #else
 120           *exitstat = res;
 121 #endif
 122         }
 123     }
 124
 125   free (cmd);
 126
 127   /* Now copy back to the Fortran string if needed.  */
 128   if (cmdstat && *cmdstat > EXEC_NOERROR && cmdmsg)
 129     fstrcpy (cmdmsg, cmdmsg_len, cmdmsg_values[*cmdstat],
 130                 strlen (cmdmsg_values[*cmdstat]));
 131 }
 132
 133
 134 extern void
 135 execute_command_line_i4 (const char *command, GFC_LOGICAL_4 *wait,
 136                          GFC_INTEGER_4 *exitstat, GFC_INTEGER_4 *cmdstat,
 137                          char *cmdmsg, gfc_charlen_type command_len,
 138                          gfc_charlen_type cmdmsg_len);
 139 export_proto(execute_command_line_i4);
 140
 141 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 {
 147   bool w = wait ? *wait : true;
 148   int estat, estat_initial, cstat;
 149
 150   if (exitstat)
 151     estat_initial = estat = *exitstat;
 152
 153   execute_command_line (command, w, &estat, cmdstat ? &cstat : NULL,
 154                         cmdmsg, command_len, cmdmsg_len);
 155
 156   if (exitstat && estat != estat_initial)
 157     *exitstat = estat;
 158   if (cmdstat)
 159     *cmdstat = cstat;
 160 }
 161
 162
 163 extern void
 164 execute_command_line_i8 (const char *command, GFC_LOGICAL_8 *wait,
 165                          GFC_INTEGER_8 *exitstat, GFC_INTEGER_8 *cmdstat,
 166                          char *cmdmsg, gfc_charlen_type command_len,
 167                          gfc_charlen_type cmdmsg_len);
 168 export_proto(execute_command_line_i8);
 169
 170 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 {
 176   bool w = wait ? *wait : true;
 177   int estat, estat_initial, cstat;
 178
 179   if (exitstat)
 180     estat_initial = estat = *exitstat;
 181
 182   execute_command_line (command, w, &estat, cmdstat ? &cstat : NULL,
 183                         cmdmsg, command_len, cmdmsg_len);
 184
 185   if (exitstat && estat != estat_initial)
 186     *exitstat = estat;
 187   if (cmdstat)
 188     *cmdstat = cstat;
 189 }