[root@perflnx14 SCRIPTS]# crontab -l * * * * * /root/nfs_share/SCRIPTS/cron_ncp.pl >>/root/nfs_share/SCRIPTS/temp.txt ---------------- cron_tab.pl script: #!/usr/bin/perl use warnings; use strict; #my $cmd='nohup expect -f /root/nfs_share/SCRIPTS/ncp_run.tcl &'; my $cmd='nohup /root/nfs_share/SCRIPTS/ncp_run.tcl &'; #my $tmp= `ps -ef | grep -v grep | grep ncp_run.tcl | wc -l`; my $tmp= `ps -ef | grep -c [n]cp_run.tcl`; if($tmp == 1) { print"already running\n"; } else { print"not running\n"; system $cmd; }