i am a dummy in ksh now i need to write a script to join a some file, either by joining 50 files to one file, or join the files in one after timeout. can anyone help me out?

Your question is too vague for me to answer it.

so sorry for that. i actually need to have the xxid.txt file in the log dir join under two condition: 1) when the dir's file reaches 50 files 2) after timeout of maybe 1 min if less than 50 files in that dir. it's quite tough for me since i never do one before. thanks in advance for the help.

Create two process, one will sleep for 60 seconds, then will kill the other process if it exists and join the files and then exit. The other one will continue to monitor the directory in 2 sec gap, if no of file is more than 50, then join the files, kill the other process and exit. My suggestion is write two scripts: Script1: #!/usr/bin/ksh rm -f /tmp/Temp.Script1 2>/dev/null touch /tmp/Temp.Script1 echo $$ > /tmp/Temp.Script1 sleep 60 #I assume one min is timeout if [ -s /tmp/Temp.Script2 ] then kill -9 `cat /tmp/Temp.Script2` 2>/dev/null cat `ls $logdir` > xxid.txt fi exit 0 Script2: #!/usr/bin/ksh rm -f /tmp/Temp.Script2 2>/dev/null touch /tmp/Temp.Script2 echo $$ > /tmp/Temp.Script2 wait=0 Script1 & #In the background while [ $wait -eq 0 ] do no_of_file=$(ls $logdir | wc -l) if [ $no_of_file -ge 50 ] then cat `ls $logdir` > xxid.txt wait=1 else sleep 2 fi done rm -f /tmp/Temp.Script2 2>/dev/null if [ -s /tmp/Temp.Script1 ] then kill -9 `cat /tmp/Temp.Script1` 2>/dev/null fi exit 0