USAGE

Unix: awk ‘/pattern/ {print “$1”}’ # standard Unix shells DOS/Win: awk ‘/pattern/ {print “$1”}’ # okay for DJGPP compiled awk “/pattern/ {print \”$1\”}” # required for Mingw32 Most of my experience comes from version of GNU awk (gawk) compiled for Win32. Note in particular that DJGPP compilations permit the awk script to follow Unix […]

If you want to use bash’s printf formatting and store the value into a variable, you can use bash’s print’s -v flag as follows:

calc_elaspsed_time() { local SECONDS=$1 ((h=SECONDS/3600)) ((m=SECONDS%3600/60)) ((s=SECONDS%60)) printf -v ELAPSED_TIME “%02d:%02d:%02d” $h $m $s }

printf Command The built-in printf (print formatted) command prints a message to the screen. You […]

Command line argument in shell script Passing arguments to the main program when it start is know as command line arguments In shell scripting arguments can be described like below

$0 – shows program name which you running $1 – shows first argument $2 – display second argument $3 – display third argument $n – […]

Reading from a file

for line in $(cat /etc/passwd) do echo $line done

Iterate for a range

for number in {1..10} do echo “Current number is $number” done

Loop for values given

for planet in earth mars saturn jupiter do echo “The planet name is $planet” done

Loop for variable containing multiple values

planets=”earth mars […]