Shell Programming and Scripting

#!/bin/sh 
# 
# 
# MD5FILE-parameter specifies where we want to save our md5print for 
# later use. 
MD5FILE=/tmp/.md5savefile 

# The FILE_TO_CHECK-parameter specifies the file we want to monitor 
# changes 
FILE_TO_CHECK=/tmp/filetocheck 

if [ ! -f $FILE_TO_CHECK ] 
then 
echo "ERROR Couldnt locate file to check:$FILE_TO_CHECK" 
exit 1 
fi 

echo "Taking a print on $FILE_TO_CHECK with md5sum" 
MD5PRINT=`md5sum $FILE_TO_CHECK | cut -d " " -f2` 

if [ -z $MD5PRINT ] 
then 
echo "ERROR Recived an empty MD5PRINT thats not valid, aborting" 
exit 1 
else 
echo "MD5PRINT we got was:$MD5PRINT" 
fi 

if [ -f $MD5FILE ] 
then 
echo "Found an old savefile:$MD5FILE we trying to match prints" 
OLDMD5PRINT=`cat $MD5FILE` 

if [ -z $OLDMD5PRINT ] 
then 
echo "Got an empty string from the oldfile, aborting" 
exit 1 
fi

if [ "$OLDMD5PRINT" = "$MD5PRINT" ] 
then 
echo "New and old md5print are identical, the file hasnt been changed" 
else 
echo "WARNING the old and new md5print doesnt match, the file has been changed" 
fi 

fi 

echo "Saving to new md5print in logfile:$MD5FILE for later checks" 
echo $MD5PRINT > $MD5FILE 

if [ $? = 0 ] 
then 
echo "Wrote to file OK" 
else 
echo "Writing to file failed...why??" 
exit 1 
fi

#!/bin/sh
#
#
# MD5FILE-parameter specifies where we want to save our md5print for
# later use.
MD5FILE=/tmp/.md5savefile

# The FILE_TO_CHECK-parameter specifies the file we want to monitor
# changes
current_date=`date +%Y%m%d`
FILE_TO_CHECK=MSN.htm

if [ ! -f $FILE_TO_CHECK ]
then
echo "ERROR Couldnt locate file to check:$FILE_TO_CHECK"
exit 1
fi

echo "Taking a print on $FILE_TO_CHECK with md5sum"
MD5PRINT=`md5sum $FILE_TO_CHECK | cut -d " " -f2`

if [ -z $MD5PRINT ]
then
echo "ERROR Recived an empty MD5PRINT thats not valid, aborting"
exit 1
else
echo "MD5PRINT we got was:$MD5PRINT"
fi

if [ -f $MD5FILE ]
then
echo "Found an old savefile:$MD5FILE we trying to match prints"
OLDMD5PRINT=`cat $MD5FILE`

if [ -z $OLDMD5PRINT ]
then
echo "Got an empty string from the oldfile, aborting"
exit 1
fi

if [ "$OLDMD5PRINT" = "$MD5PRINT" ]
then
exit 1
else
cp MSN.htm  MSN.$current_date.htm
fi

fi

echo "Saving to new md5print in logfile:$MD5FILE for later checks"
echo $MD5PRINT > $MD5FILE

if [ $? = 0 ]
then
echo "Wrote to file OK"
else
echo "Writing to file failed...why??"
exit 1
fi

#!/bin/bash

# If we have no /tmp/.md5sum
if [ ! -f /tmp/.md5sum ]
then
        echo "Generating new checksum file" >&2
        md5sum /path/to/file > /tmp/.md5sum
        # Return error if .md5sum couldn't be created
        [ -f /tmp/.md5sum ] || exit 1
        exit 0
fi


# Check if file has changed, quit if it hasn't.
md5sum -c /tmp/.md5sum && exit 0

echo "File has changed, do things here" >&2

# ...
# ... ftp and stuf
# ...

echo "Generating new checksum file" >&2
md5sum /path/to/file > /tmp/.md5sum

exit