Session contents

Text processing with sed

• Use of ! for negation
• Use of -n, -i and -f flags
• Use of g, p, and w commands

Construction of shell script

• Review of steps

Variables

• Variables ${var}
• Length of variable ${#var}
• Removing substrings ${var#}, ${var##}, ${var%}, ${var%%}
• Pattern substitution ${var/p/r}, ${var//p/r}
• Prefix and suffix substitution ${var/#p/r}, ${var/%p/r}
• Use of declare with -i, -r attributes

Arrays

• Index and associative arrasys with decalre -a, declare -A
• Indexing with $arr, ${arr[0]}, $arr[@]

Conditionals

• tests with [[]] and (())
• test file operators

Branching

• if

if CONDITION then;
  commands
fi

• case

case EXPR in
PATTERN)
  commands ;;
Pattern
  commands ;;
esac

Looping

• for type 1

for EXPR in Sequence
do
  commands
done

• for type 2

for (( i=0; i<n; i++ ))
do
  commands
done

• while

while Condition
do
  commands
done

• until

until Condition
do
  commands
done

Process control

• &, fg and Ctrl-z bg
• ps, ps -a, ps -e
• jobs
• kill and kill signals man kill, kill -l, man signal