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Here is an example which uses all the file test operatos:
Assume a variable file holds an existing file name "/var/www/tutorialspoint/unix/test.sh" whose size is 100 bytes and has read, write and execute permission on:
#!/bin/sh file="/var/www/tutorialspoint/unix/test.sh" if [ -r $file ] then echo "File has read access" else echo "File does not have read access" fi if [ -w $file ] then echo "File has write permission" else echo "File does not have write permission" fi if [ -x $file ] then echo "File has execute permission" else echo "File does not have execute permission" fi if [ -f $file ] then echo "File is an ordinary file" else echo "This is sepcial file" fi if [ -d $file ] then echo "File is a directory" else echo "This is not a directory" fi if [ -s $file ] then echo "File size is zero" else echo "File size is not zero" fi if [ -e $file ] then echo "File exists" else echo "File does not exist" fi |
This would produce following result:
File has read access File has write permission File has execute permission File is an ordinary file This is not a directory File size is zero File exists |
There are following points to note down:
There must be spaces between operators and expressions for example 2+2 is not correct, where as it should be written as 2 + 2.
if...then...else...fi statement is a decision making statement which has been explained in next chapter.
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