Hi there,

would be great if you can help me. I have to find unwanted characters in a file, and all I have is a positive list of allowed characters as regular expression [a-zA-Z0-9 \[\]{}#\,\.();]. Using awk makes no sense, as each line also contains one of the allowed chars and isn´t found thereby :(

Thanks in advance

Criamon

I did the same job before.

I wrote a very simple C program using getc() to read the char one by one from the input file. If the char is in [a-zA-Z0-9 \[\]{}#\,\.();], then putc() to the output file, else do nothing.

It was a very simple C program.

Luke Chi

Try this following command, it work on Redhat 9:

awk '!/[[:almun:]\[\]{}#,.();]/' file.txt

It will list all lines not match the regular expression.

sed 's/[^a-zA-Z0-9 \[\]{}#\,\.();]//g' file.txt

Luke Chi