![13
while loop Examplewhile loop Example
a=0
while [ $a -lt 10 ]
do
echo $a
a=`expr $a + 1`
done](https://image.slidesharecdn.com/ch-8advancedscripting-2-160303045538/85/Advanced-Scripting-2-Ch-8-13-320.jpg)
![16
until loop Exampleuntil loop Example
until [ $DISKFUL -ge "90" ];
do
DATE=`date +%Y%m%d`
HOUR=`date +%H`
mkdir $WEBDIR/"$DATE"
while [ $HOUR -ne "00" ];
do
DESTDIR=$WEBDIR/"$DATE"/"$HOUR"
mkdir "$DESTDIR" mv $PICDIR/*.jpg "$DESTDIR"/
sleep 3600 HOUR=`date +%H`
done](https://image.slidesharecdn.com/ch-8advancedscripting-2-160303045538/85/Advanced-Scripting-2-Ch-8-16-320.jpg)
Advanced Scripting - 2 (Ch-8)
- 2. 2 What is Handling Repetition ? Handling Repetition is control structure also known as looping control structure,Handling Repetition is control structure also known as looping control structure, is a type of control structure in programming languages that is used to simplify repetitive oris a type of control structure in programming languages that is used to simplify repetitive or recursive tasks operation.recursive tasks operation.
- 3. Delete zero sized files in system.Delete zero sized files in system. 3 Code for write a script to delete zero sized files from a given directory (and all its subdirectories) in Unix / Linux / Ubuntu Code for write a script to delete zero sized files from a given directory (and all its subdirectories) in Unix / Linux / Ubuntu
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- 5. 5 Script 19 Handling Repetition is control structure also known as looping control structure,Handling Repetition is control structure also known as looping control structure, is a type of control structure in programming languages that is used to simplify repetitive oris a type of control structure in programming languages that is used to simplify repetitive or recursive tasks operation.recursive tasks operation.
- 6. 6 Repetitive tasks 1.1. The for loopThe for loop 2.2. The while loopThe while loop 3.3. The until loopThe until loop
- 7. 7 The for loopThe for loop The for loop is the first of the three shell looping constructs. This loop allows for specification of a list of values. A list of commands is executed for each value in the list.
- 8. 8 for loop Syntaxfor loop Syntax
- 9. 9 for loop Examplefor loop Example $ cat for1.sh i=1 for day in Mon Tue Wed Thu Fri do echo "Weekday $((i++)) : $day" done $ ./for1.sh Weekday 1 : Mon Weekday 2 : Tue Weekday 3 : Wed Weekday 4 : Thu Weekday 5 : Fri
- 10. 10 The while loopThe while loop The while construct allows for repetitive execution of a list of commands, as long as the command controlling the while loop executes successfully (exit status of zero) The while construct allows for repetitive execution of a list of commands, as long as the command controlling the while loop executes successfully (exit status of zero)
- 11. 11 The while loopThe while loop
- 12. 12 while loop Syntaxwhile loop Syntax
- 13. 13 while loop Examplewhile loop Example a=0 while [ $a -lt 10 ] do echo $a a=`expr $a + 1` done
- 14. 14 The until loopThe until loop
- 15. 15 until loop Syntaxuntil loop Syntax until <TEST-COMMAND>; do CONSEQUENT - COMMANDS; done
- 16. 16 until loop Exampleuntil loop Example until [ $DISKFUL -ge "90" ]; do DATE=`date +%Y%m%d` HOUR=`date +%H` mkdir $WEBDIR/"$DATE" while [ $HOUR -ne "00" ]; do DESTDIR=$WEBDIR/"$DATE"/"$HOUR" mkdir "$DESTDIR" mv $PICDIR/*.jpg "$DESTDIR"/ sleep 3600 HOUR=`date +%H` done
- 18. 18 What is Function ? A function is a subroutine, a code block that implements a set of operations, a "black box" that performs a specified task. Wherever there is repetitive code, when a task repeats with only slight variations in procedure, then consider using a function.
- 19. 19 Syntax of Function ? function function_name { command... } or function_name () { command... }
- 20. 20 Example of Function ?
- 21. 21 Example of Function ?
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