Shell Programming and Scripting

Hi Bakunin,

Here is the modified script that i come up with your suggestion:

Code:

#!/bin/bash
typeset -i lines_in_primery=0

while IFS=',' read name id_number ; do
   name_directory=/usr/myproject/content_to_add/config/$name
   if [ -d $name_directory ] ; then
      lines_in_primery=$(sed -n '$ =' $name_directory/primery.txt)
      if [ $lines_in_primery -lt 5 ] ; then
         echo $id_number >> $name_directory/primery.txt
      else
         echo $id_number >> $name_directory/secondry.txt
      fi
   else
      echo directory $name does not exit >>logs ;
   fi
done < /usr/myproject/content_to_add/master_file

I have done some initial round of tests and its working fine, will check the complete functionality.

I think the error was because i was not setting "lines_in_variable" to integer. whats your opinion?

Thanks again for your help.

I'm glad it works. Why your error occurred i have no idea. The shell soes not really differentiate between data types like high-level-languages and even if a string variable contains a numeric value it should work:

Code:

x="5"
if [ $x -lt 10 ] ; then
     echo "it works"
fi

Will work. It would only throw an error when "$x" contains something which can't be interpreted as integer, like "blabla".

The error message suggests that the variable was completely empty, so probably something went wrong when you assigned it a value.

A final suggestion: quote variable contents! For instance, try the following lines:

Code:

name="abc"
name_directory=/usr/myproject/content_to_add/config/$name
if [ -d $name_dir ] ; then
     echo "It works."
fi

If you create the directory "/usr/myproject/content_to_add/config/abc" this will produce the message as expected. Now create the directory "/usr/myproject/content_to_add/config/ab c" (it is possible if you enclose it in double quotes) and try the above code again, replacing "abc" with "ab c". It will throw an error.

The reason is the shell has to somehow know where a word ends and another starts. Every time it encounters a space char it declares the word it is reading at that moment to be finished. If you type "mv a b" it this leads to "mv", "a" and "b" being interpreted as different words (the first being a command, the two others file names) and this is like one would expect things to work. But suppose a file is named "a b": how would you tell the shell to move that? This is called "word splitting" and it is performed on every line during the parsing process. Enclosing something in double quotes is to protect that part from this word splitting and therefore it is a good idea to write:

Code:

name="abc"
# name="ab c"

name_directory="/usr/myproject/content_to_add/config/$name"
if [ -d "$name_dir" ] ; then
     echo "It works."
fi

Which you will notice will work even with a file with spaces in its name. Try it out!

I hope this helps.

bakunin

Thanks Bakunin,

I will take care of this in future.