Python in a Nutshell

Name

execl, execle, execlp, execv, execve, execvp, execvpe

Synopsis

execl(path,*args)
execle(path,*args)
execlp(path,*args)
execv(path,args)
execve(path,args,env)
execvp(path,args)
execvpe(path,args,env)

These functions run the executable file (program) indicated by string path, replacing the current program (i.e., the Python interpreter) in the current process. The distinctions encoded in the function names (after the prefix exec) control three aspects of how the new program is found and run:

• Does path have to be a complete path to the program’s executable file, or can the function also accept just a name as the path argument and search for the executable in several directories, like operating system shells do? execlp, execvp, and execvpe can accept a path argument that is just a filename rather than a complete path. In this case, the functions search for an executable file of that name along the directories listed in os.environ['PATH']. The other functions require path to be a complete path to the executable file for the new program.

• Are arguments for the new program accepted as a single sequence argument args to the function or as separate arguments to the function? Functions whose names start with execv take a single argument args that is the sequence of the arguments to use for the new program. Functions whose names start with execl take the new program’s arguments as separate arguments (execle, in particular, uses its last argument as the environment for the new program).

• Is the ...