https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62296
--- Comment #1 from Harald Anlauf <anlauf at gmx dot de> --- There was some confusion on my side regarding the semantics of the CMDSTAT argument on my side. I asked at https://groups.google.com/forum/?hl=en#!topic/comp.lang.fortran/6ymZIb6flDg where there was consensus that CMDSTAT should be zero if the command line could be executed, even if the exit status is non-zero. However, if the command could *not* be executed, there should be a non-zero value for CMDSTAT. However, modifying the code to integer :: stat, cstat character(len=255) :: cmdmsg cmdmsg = "" call execute_command_line ("/bin/true", exitstat=stat, cmdstat=cstat, cmdmsg=cmdmsg) print *, stat, cstat, "'", trim (cmdmsg), "'" call execute_command_line ("/bin/false", exitstat=stat, cmdstat=cstat, cmdmsg=cmdmsg) print *, stat, cstat, "'", trim (cmdmsg), "'" call execute_command_line ("/nosuchfile",exitstat=stat, cmdstat=cstat, cmdmsg=cmdmsg) print *, stat, cstat, "'", trim (cmdmsg), "'" call execute_command_line ("/bin/true", exitstat=stat) print *, stat call execute_command_line ("/bin/false", exitstat=stat) print *, stat call execute_command_line ("/nosuchfile",exitstat=stat) print *, stat end produces: 0 0 '' 1 0 '' sh: /nosuchfile: No such file or directory 127 0 '' 0 1 sh: /nosuchfile: No such file or directory 127 Thus the attempt to execute a non-existing command does not lead to an appropriate error. Looking at execute_command_line.c, the execution uses system(). The Linux man page system(3) says: It is possible for the shell command to return 127, so that code is not a sure indication that the execve(2) call failed. Unfortunately the man page does not say whether errno is set, as it is done for execve(2). So it might be necessary to replace system(3) by something like fork/exec to get the error status.
