Function std.process.execvp
Replaces the current process by executing a command, pathname, with
the arguments in argv.
int execvp
(
const(string) pathname,
const(string[]) argv
);
int execvp
(
const(string) pathname,
const(string[]) argv
);
This function is Posix-Only.
Typically, the first element of argv is
the command being executed, i.e. argv[0] == pathname. The 'p'
versions of exec search the PATH environment variable for pathname. The 'e' versions additionally take the new process'
environment variables as an array of strings of the form key=value.
Does not return on success (the current process will have been replaced). Returns -1 on failure with no indication of the underlying error.
Windows specific
These functions are only supported on POSIX platforms, as the Windows
operating systems do not provide the ability to overwrite the current
process image with another. In single-threaded programs it is possible
to approximate the effect of execv* by using spawnProcess
and terminating the current process once the child process has returned.
For example:
auto commandLine = [ "program", "arg1", "arg2" ];
version (Posix)
{
execv(commandLine[0], commandLine);
throw new Exception("Failed to execute program");
}
else version (Windows)
{
import core This is, however, NOT equivalent to POSIX' execv*. For one thing, the
executed program is started as a separate process, with all this entails.
Secondly, in a multithreaded program, other threads will continue to do
work while the current thread is waiting for the child process to complete.
A better option may sometimes be to terminate the current program immediately
after spawning the child process. This is the behaviour exhibited by the
_exec
functions in Microsoft's C runtime library, and it is how D's now-deprecated
Windows execv* functions work. Example:
auto commandLine = [ "program", "arg1", "arg2" ];
version (Posix)
{
execv(commandLine[0], commandLine);
throw new Exception("Failed to execute program");
}
else version (Windows)
{
spawnProcess(commandLine);
import coreAuthors
Lars Tandle Kyllingstad, Steven Schveighoffer, Vladimir Panteleev