Shell Programming and Scripting

Hi,

I want to do the following validations in my script when my script gets 2 parameters as command line inputs.

My script expects 2 inputs : a -f option and a filename

If a filename is given as input without the -f option then I have to exit. If only -f option is given and no filename is given then also I have to exit.

Once I get both the inputs I have to check whether the file has read permissions or not.

Please provide me a snippet of code as of how to do this.

Thanks in advance

Let us see what you've tried!

Check this if you can find something help regarding user input validation.

If one parameters is fixed i.e. -f, why you are expecting it from the user input? why dont you use it in your shell script itself. And as manthasirisha said, post your code here.

Regards,
Tayyab

Hi,
It worked. But the only thing is that when I put the same code in a function it doesnt work. It says test argument expected in the line where i check for the existence of the file

v=$1
if [ $v = -f ]
then
echo "ok"

if [ -f $2 ]
then
echo "exists"

if [ -r $2 ]
then
echo "Read permissions exists for the file"


sed '2,2d' $2 > sdh_reconfig_modify_dl.tmp
more sdh_reconfig_modify_dl.tmp | grep -q "^|"
if (($?!=0))
then
echo "ok"

while read line
do
tmp1=`echo ${#line}`
line=`echo $line | sed 's/|//g'`
cnt=$(($tmp1 - `echo ${#line}`))

if [ \( $cnt -ne 1 \) ]
then
echo "The fields in the file must be seperated by a |"
exit 1
echo "File format is correct. Proceeding for further execution..."
fi
done < sdh_reconfig_new_dl.tmp

tr '|' ' ' < sdh_reconfig_new_dl.tmp > sdh_reconfig_new_dl1.tmp
exec < sdh_reconfig_new_dl1.tmp
read dl1 dl2
echo $dl1
echo $dl2


else
echo "File cannot start with a |"
exit
fi


else
echo "The file doesnot have read permissions"
exit
fi

else
echo "The file that you have entered does not exist"
exit
fi
else
echo "The filename must be preceeded by a -f option"
exit
fi

Function that expects arguments need to have them , isn't it?

Try calling your function by passing the relevant parameters. Say, if you're passing the filename alone, then u may do:

func1 <<filename>>
Do post the error and the function call, if u still have trouble!

If the filename is all that you need, why have a -f flag ? It is not needed unless you have other flags, or plan to introduce other flags.

The script could be as simple as

Code:

#! /bin/ksh

if [[ $# -eq 1 ]] ; then
  # we have a filename
  FILE="$1"
else
  # we have more than 1 argument. Exit
  exit 1;
fi ;

if [[ -r "$FILE" ]] ; then 
  echo "$FILE exists and is readable"
else
  echo "Either not a file, or not readable"
  exit 1;
fi;

Not tested tho'.

Hi, Sorry for the late reply. It worked when I passed the parameters to the function. Thanks.