ksh comparing strings using if:fi statement

[southbeach]

I have this simple script

#!/bin/ksh
MyString=/dir/dir/dir/34/54/39/98-1.pdf
x=${#MyString}
echo "x: ${x}"
y=1
#while (( y <= ${#MyString} ))
while (( x > 0 ))
do
  xchar=$(expr substr "$MyString" $x 1)
  if (( "${xchar}" == "/" ));
  then
          echo "fname set to: ${fname}"
          exit
  fi
  fname="${xchar}${fname}"
  let x=x-1
done

I need to extract the file name off a given directory tree or path. I am having hell of a hard time comparing two simple strings as attempted above.

I have tried various approaches using awk and other syntax as I've found online but nothing seems to work.

I have resolved to parse through the string from end of string back until I find the first "/" thus presumably having successfully extracted the file name into a string "$fname"

That being said, I am running into an "arithmetic syntax error" on line 10 that reads

line 10:  "f" == "/" : arithmetic syntax error

Any assistance with this will be truly appreciated!

Thanks,


--
SouthBeach

http://www.fpgroups.com

The good thing about not knowing is the opportunity to learn - Yours truly, 2008.

 

[southbeach]

Never mind, solved it!

#!/bin/ksh
MyString=/dir/dir/dir/34/54/39/98-1.pdf
x=${#MyString}
echo "x: ${x}"
y=1
#while (( y <= ${#MyString} ))
while (( x > 0 ))
do
  xchar=$(expr substr "$MyString" $x 1)
  if [ ${xchar} == "/" ];
  then
          echo "fname set to: ${fname}"
          exit
  fi
  fname="${xchar}${fname}"
  let x=x-1
done

Notice change within if:fi expression! ;-)


--
SouthBeach

http://www.fpgroups.com

The good thing about not knowing is the opportunity to learn - Yours truly, 2008.