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EXECUTE_COMMAND_LINE
— Execute a shell commandEXECUTE_COMMAND_LINE
runs a shell command, synchronously or
asynchronously.
The COMMAND
argument is passed to the shell and executed (The
shell is sh
on Unix systems, and cmd.exe
on Windows.).
If WAIT
is present and has the value false, the execution of
the command is asynchronous if the system supports it; otherwise, the
command is executed synchronously using the C library’s system
call.
The three last arguments allow the user to get status information. After
synchronous execution, EXITSTAT
contains the integer exit code of
the command, as returned by system
. CMDSTAT
is set to zero
if the command line was executed (whatever its exit status was).
CMDMSG
is assigned an error message if an error has occurred.
Note that the system
function need not be thread-safe. It is
the responsibility of the user to ensure that system
is not
called concurrently.
For asynchronous execution on supported targets, the POSIX
posix_spawn
or fork
functions are used. Also, a signal
handler for the SIGCHLD
signal is installed.
Fortran 2008 and later
Subroutine
CALL EXECUTE_COMMAND_LINE(COMMAND [, WAIT, EXITSTAT, CMDSTAT, CMDMSG ])
COMMAND | Shall be a default CHARACTER scalar. |
WAIT | (Optional) Shall be a default LOGICAL scalar. |
EXITSTAT | (Optional) Shall be an INTEGER of the
default kind. |
CMDSTAT | (Optional) Shall be an INTEGER of the
default kind. |
CMDMSG | (Optional) Shall be an CHARACTER scalar of the
default kind. |
program test_exec integer :: i call execute_command_line ("external_prog.exe", exitstat=i) print *, "Exit status of external_prog.exe was ", i call execute_command_line ("reindex_files.exe", wait=.false.) print *, "Now reindexing files in the background" end program test_exec
Because this intrinsic is implemented in terms of the system
function call, its behavior with respect to signaling is processor
dependent. In particular, on POSIX-compliant systems, the SIGINT and
SIGQUIT signals will be ignored, and the SIGCHLD will be blocked. As
such, if the parent process is terminated, the child process might not be
terminated alongside.
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