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Ignore lines in Shell Script


 
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# 1  
Old 04-18-2012
Ignore lines in Shell Script

Hi,

I have a shell script, which reads a *.txt file - line by line. In this text file, I have some lines beginning with "#" that I want to ignore :

MY_FILE
Code:
 
#blah blah blah 1
blah blah blah 2
blah blah blah 3
#blah blah blah 4

I want my script to read only the following lines and process them:
Code:
 
blah blah blah 2
blah blah blah 3

Is there a way to incorporate this in my shell script?

Code:
 
#!/bin/bash
MY_FILE=$1
 
[ $# -eq 0 ] && { echo "Usage: $0 <filename>"; exit 1; }
 
while read line 
do
.......
.......
......
.....
....
done <  "$MY_FILE"

# 2  
Old 04-18-2012
Check if the first character is # and if so, ignore the line.

Code:
while read LINE
do
        [ "${LINE:0:1}" = "#" ] && continue

        ...
done

This syntax should work in bash and ksh.
# 3  
Old 04-18-2012
Thanks,

Works like a charm!
# 4  
Old 04-18-2012
Alternatively you could strip out lines starting with a pound sign before feeding them to the while loop:
Code:
#!/bin/bash

MY_FILE=$1

grep -v "^#" $MY_FILE | while read LINE
do
  echo $LINE
done

exit 0


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