Shell Programming and Scripting

Hi,
I am trying to weed out DOS '^M' new-line characters from a file which I copied from windows inside my Linux box, using this following script. But it seems this script is not working properly if I have made a check 'xargs grep -l "\012$"'. Here, I am trying to filter only the files which contains the octal code of '\n'. Though I can grep directly '^M', I want to know why this script fails at this point, so pls tell me what I am doing wrong.

Code:

for fil in `find . -type f -name "*" | xargs grep -l "\012$" | xargs file | grep text | cut -d: -f1`
do
    tr -d "\015\032" < $fil > "${fil}".tmp
    mv "${fil}".tmp $fil
done

Why are you looking for \n? By definition, if they are text files (and do not consist of a single line without any line ending terminator) they will have newlines in them. And grep can't grep for those, it greps the actual contents of the line but internally doesn't see the newlines.

Grepping for \015 (aka ^M, aka \r) before you attempt to remove it would make some sense. But unless the files are very large, it might make more sense to simply tr them all and then just remove the temp file if it's identical to the original.

A large backtick expression like that is pretty hard to debug, kudos for pulling it off. I would have refactored it into a while loop, though.

Code:

find . -type f |  # name "*" is redundant, isn't it?
# xargs grep -l '\015$' |  # ?  or grep -l '^M$' (that's opening quote, ctrl-v ctrl-m dollar sign, closing quote)
xargs file |
grep text |
cut -d: -f1 |
while read fil; do ...

My GNU grep can't grep for \octal codes anyway.

if you are just getting rid of new line characters, run your files through the dos2unix command.

Thanks era for a clear illustration.

Could you tell me what purpose does '\032' serve in my script, i.e what symbol it is for?

Thanks ghostdog for the suggestion, however I would like to use script only rather a command.

\032? No idea, but I bet your man ascii will tell you it's a control code one less than ESC called SUB. Never seen that in anything but then I have no idea what file type you are processing anyway. Ask somebody who does?