Linux Shell String Comparison

Hi Folks,


If you remember when you work on creating own Linux/Unix shell script, you would always be involved in if-else, case comparison. Thus, this article to share the string comparison you can use while using if-else or other comparison method. Hope this helps!


String Comparisons

= equal
!= not equal
< less then
> greater then
-n s1 string s1 is not empty
-z s1 string s1 is empty


Bash File Testing

-b filename Block special file
-c filename Special character file
-d directoryname Check for directory existence
-e filename Check for file existence
-f filename Check for regular file existence not a directory
-G filename Check if file exists and is owned by effective group ID.
-g filename true if file exists and is set-group-id.
-k filename Sticky bit
-L filename Symbolic link
-O filename True if file exists and is owned by the effective user id.
-r filename Check if file is a readable
-S filename Check if file is socket
-s filename Check if file is nonzero size
-u filename Check if file set-ser-id bit is set
-w filename Check if file is writable
-x filename Check if file is executable