nels, First, an if-statement should use -eq for numeric compares, but for string compares like this, it should use =.  And "then" is a separate command, so it should begin a new line (or separate with semicolon). Secondly, the expression "\f" will be interpreted by the shell as just a simple f character.  You precede any character with backslash to make it lose its special meaning to the shell and be taken as just itself.  Example: echo I won \$5. The following code demonstrates this, and shows that the echo command will interpret "\f" as the formfeed character. f1="f" f2="\f" eval f3="\f" f4=$(echo "\f") expr length $f1 expr length $f2 expr length $f3 expr length $f4 cat > f.out << ! f1=$f1 f2=$f2 f3=$f3 f4=$f4 ! echo '========' cat f.out echo '========' 1 2 1 1 ======== f1=f f2=\f f3=f f4= ======== f4 is a formfeed character, but it displays to the screen (as above) as a line break.  But if you read f.out into vi, you will see the ^L. So with all that said, your command is actually close to what you need. Instead of: if [ `tail -n 1 $1` -eq "\f" ] then ..... you can use this instead: if [ "`tail -n 1 $1`" = `echo "\f"` ] ; then ..... or I prefer the ksh syntax: if [ "$(tail -n 1 $1)" = $(echo "\f") ] ; then ..... And you should enclose the first argument in double-quotes as shown.  If the last line of the file is a null line, it would cause a syntax error unless the argument were in double-quotes. And while you do not need your other approach of using the ff file, that approach would have worked had you used the proper syntax.  Instead of: if [ `tail -n 1 $1` ] -eq [ `tail -n 1 ff` ]then ... you could use this instead: if [ "`tail -n 1 x1`" = `tail -n 1 ff` ] ; then ... The solution provided by nails would return a positive indication if the last line were null.

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Dear Jim, I really can't imagine that you provided me that full and clear explanation! Especially the exception case! What I can say is really thanks for you help & explanation. BTW, I still have a bit blur about the below code, can you give me some guideline or explaning?? What i know about the cat > f.out is trying to create a file of f.out, but how about the symbol !?? is it means echo or print??? cat > f.out << ! f1=$f1 f2=$f2 f3=$f3 f4=$f4 ! Second, what will cause a null at the end of a file?? is it a empty line?? Really thanks for your help!!! Best Regards, Nels

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You will sometimes see that referred to as a "here document". In a script, that is one way to feed lines into a command. It is common to use the exclamation mark, but any word will do, such as: ftp -n myserver << ENDIT user oracle mypasswd prompt cd /u01/prod/database mget * bye ENDIT The reason that I used cat to send the variables to either the screen or an output file is because in this demonstration I must avoid the echo command because it does its special interpretation and thus alters the results that I want to show - namely that the shell does not interpret "\f" as a formfeed. And yes, an empty line is same as a null line - nothing on it, not even spaces. It's length is zero, whereas lines having one or more spaces would have non-zero length. In the following, the first checks for empty (null) lines, the second checks for lines with no words on it, which would include empty lines and lines with spaces and tabs, and the third prints the length of each line: awk 'length==0' myfile awk 'NF==0' myfile awk '{print length}' myfile

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