Question

I am using following kind of script in my perl script and expecting entry at line 1. I am getting some error as below; any help?

plz ignore perl variable….

Error Messaage –
sed: -e expression #1, char 22: extra characters after command

# Empty file will not work for Sed line number 1
    `"Security Concerns Report" > $outputFile`;

    `sed '1i\
    \
    DATE :- $CDate \
    Utility accounts with super access:- $LNumOfSupUserUtil \
    Users not found in LDAP with super access: - $LNumOfSupUserNonLdap\

    ' $outputFile > $$`;
    `mv $$ $outputFile`;
}

Answer 1

Your immediate problem is that the backslash character is interpreted by Perl inside the backtick operator, as is the dollar character. So your backslash-newline sequence turns into a newline in the shell command that is executed. If you replace these backslashes by \\, you’ll go over this hurdle, but you’ll still have a very brittle program.

Perl is calling a shell which calls sed. This requires an extra level of quoting for the shell which you are not performing. If your file names and data contain no special characters, you may be able to get away with this, until someone uses a date format containing a ' (among many things that would break your code).

Rather than fix this, it is a lot simpler to do everything in Perl. Everything sed and shells can do, Perl can do almost as easily or easier. It’s not very clear from your question what you’re trying to do. I’ll focus on the sed call, but this may not be the best way to write your program.

If you really need to prepend some text to an existing file, there’s a widely-used module on CPAN that already does this well. Use existing libraries in preference to reinventing the wheel. File::Slurp has a prepend_file method just for that. In the code below I use a here-document operator for the multiline string.

use File::Slurp; # at the top of the script with the other use directives
File::Slurp->prepend_file($outputFile, <<EOF);
DATE :- $CDate
Utility accounts with super access:- $LNumOfSupUserUtil
Users not found in LDAP with super access: - $LNumOfSupUserNonLdap
EOF