#!/bin/sh
#
# Version 1.00
#
# A shell script for eliminating pesky DOS or Windows
# "carriage returns" from text files such as are used for
# programming in Perl.
#
# By peter@gregg.homelinux.net
# 20th July, 2006
#
# Are you baffled by server error (500) errors while executing
# a Perl script?
#
# Although there may be other reasons, this filter
# script should eliminate one of the most common causes of the error
# especially if you are trying to execute programmes that at some stage
# have been manipulated in a DOS or Windows environment.
#
# Background:-
# In text files, DOS and Windows delineate lines with a
# carriage return line feed combination (CRLF). Linux
# (and all Unix and Unix workalikes) use only a line feed (LF).
#
# "Perl" language programmes can fail and produce server errors (500)
# if the (CRLF) end of line format exists. To safeguard against "corrupt"
# Perl scripts this shell script will filter and remove those troublesome
# carriage returns. It works on single files and on wildcards by converting
# each file from DOS/Windows to UNIX format or, if the file is already in UNIX
# format then no conversion will take place. It keeps a backup of the file used
# at the time of running the script and retains the original file date and
# time by using the "touch" command.
#
# CAUTION:-
# This script must NEVER be used against binary files because it will
# irretrievably corrupt a binary file.
#
# The script is as simple as possible however it would be a good idea
# to also backup any files on which you intend to run the script. Use a safe
# area outside the directory that holds the files you wish to filter and be sure
# to make the copies prior to the actual execution of the script on the target files.
#
# Either type or cut and paste this document into your TEXT EDITOR.
# Never use a word processor like Windows Word or Wordperfect for editing
# programmes as they add formatting information to the file that corrupts it
# for the target application. You may leave out the comments but don't forget
# to include the very first line in this script i.e."#!/bin/sh" as it is used by the
# shell in the execution of the utility.
# (It may be necessary to adjust the first line if your environment uses a
# different shell or if it is located in a different path)
# Save the file with a suitable name e.g. filterCR
# Make the file executable. e.g. chmod 755 filterCR
# Copy the executable file to the /usr/bin directory
# You should now be ready to return to the directory containing the files you
# wish to filter and run your new utility.
# At your command prompt type e.g. filterCR ./filename
#
# Your filtered file is now ready for further use in Perl.
#
while [ $1 ]; do {
     echo Converting $1
     cp $1 $1.bak
     touch -r $1 $1.bak
     cat $1.bak | sed s/[[:cntrl:]M]$//g > $1
     touch -r $1.bak $1
     shift
}
done      
#
# PS. If you find this utility saves you days of frustration similar to what
# I experienced (along others in the forum) while trying to get Everyscripts
# "eAuction" up and running due to this very reason, please consider sending
# a small donatation to Dieter Werner so that he may quench his thirst and
# keep up his excellent work on the eAuction project. You will know if the
# script has saved you much heartache if the file created after running the
# script has fewer characters in it than the original. (There will be one less
# character for each line processed)
#
# Have fun!
# Peter Gregg - Brisbane Australia