Hello, I'm trying to retreive certain bits of info from a file.

the file contains a list like this
info1:info2:info3:info4
info1:info2:info3:info4
info1:info2:info3:info4
info1:info2:info3:info4

how do i pick out only info2 or only info3 without the others?

Thanks

Lots of ways:

awk -F":" '{print $1}' file

cut -d':' -f1 file

hey thanks, one more question though. How do i tell it to keep doing this until the end of the file? Im going to make a while loop, but what would i put for the loop.

thanks

You can do something like that :

cut -d':' -f1 file |
while read field
do
    echo "Input field: $field"
done

 while FS=: read field1 field2 other_fields
do
   echo "Field1: $field1"
   echo "Field2: $Field2"
done

I just want to make sure i understand these correct. Does it take the first line and process it, then go back to the beginning and process line two and then go back and so on and so on? Or does it do it for all the lines at the same time?

Well, either of the two commands I gave will will work on the entire file. I don't see any reason why you'd need a loop just to print your chosen field.

Python alternative:

for lines in open("input.txt"):
 	lines = lines.strip().split(":")
 	print "Info 2 , second column: " , lines[1]
 	print "Info 3 , third column: " , lines[2]