system
system("command", arg0, arg1 ...) 执行命令返回结束状态
exec
The exec function
executes a system command and
never returns;
use system instead
of exec if
you want it to return. It
fails and returns false only if the command does not exist and it
is executed directly instead of via your system's command shell (see below).
readpipe
The
collected standard output of the command is returned.
In scalar context, it comes back as a single (potentially multi-line) string. In list context, returns a list of lines (however you've defined lines with $/ or $INPUT_RECORD_SEPARATOR ).
返回运行结果
my $result = readpipe("ls -l");
print $result;