exec*
execl*(path, args)
path: executable file if needed with path
args: tuple or list of strings
path has to contain the executable file including the path.
exexp*(file, a1,a2,a3,...)
file: executable file within $PATH
a1, a2, ...: strings, arguments of file: a2, a3
a1 is meaningless
file will be searched in $PATH
execle*(path, args,env)
like above but env is a dictionary with environment variables, which are implemented before execution.
exexpe*(file, a1,...,env)
like above but env is a dictionary with environment variables, which are implemented before execution.