UNIX for Beginners Questions & Answers

#!/bin/bash -i
SAVEIFS=$IFS
IFS=$"\n\b"

picc=$*
if [ -f "$picc" ]; then
echo $TDATE
if [ ! -z "$TDATE" ]; then
 touch dummy
 touch -t "tdate" dummy
 touch -r "dummy" "$picc"
else
    echo -e "No mod date value to apply. If there is one in your shell,\ninvoke \e[7msuperdate\e[0m and try again."
    exit 1
fi
fi
IFS=$SAVEIFS

TDATE=201612311234
touch -t $TDATE /tmp/dummy

#!/bin/bash -i

#!/bin/bash 
IFS=$"\n\b"

picc=$*

printf "%s\n" $picc

$ ./picc

$ ./picc eeny
ee
y
$ ./picc eeny meeny
ee
y
mee
y

IFS=$"\n\b"

IFS=$'\n\b'

$ ./picc

$ ./picc eeny
eeny
$ ./picc eeny meeny
eeny
meeny

#!/bin/bash         
                    # no need for the -i option
                    # IFS statements removed as you don't actually need them

usage() {           # Few do it but you really should have a usage
                    # function even on a script this short
   printf "Usage: %s file\n" ${0##*/}
   printf "Where file is the file to be timestamped.\n"
   printf "Remember to quote the filename if there are spaces in it.\n"
   printf "Example: %s %s\n" ${0##*/} $'"my holiday snap.jpg"'
   printf "Required environment variable: TDATE\n"
   printf "Please ensure it is exported with %s\n" $'\e[7msuperdate\e[0m'
}

if [ -z "${TDATE}" ]    # Do this test first
then                    # exit if it fails
   printf "\nTDATE not set\n\n"
   usage
   exit 1
fi

ref_file=/tmp/${0##*/}$$        # set up your reference file
trap 'rm -f "${ref_file}"' 0    # remove the reference file on exit
                                # The -f silences rm if file hasn't been created
                                # when we exit
trap 'exit' HUP INT QUIT ABRT TERM  # clean exit on any of these interrupts
                                    # Probably not useful in this short script

touch -t "${TDATE}" "${ref_file}"

picc="${1}"
if [ -z "${picc}" ] || [ ! -f "${picc}" ]
then    # can't find $picc
   printf "\nCannot find file to update!\n\n"
   usage
   exit 1
fi

touch -r "${ref_file}" "${picc}"       # business of this script 

# exit trap clears the reference file

picc=$*