Below is the code in my project I am trying to understand. Anyone can interpret what is it called? (-s and -a)
if [***-s*** $A ***-a -s*** $B]
then ..
else ..
fi
Also, Is there a dictionary wherein all of - is listed and its use?
Google search does not exactly match the information I need. Since I don't know what's called. Please help!
Thank you in advance!
You are looking for conditional expressions. Assuming you are using bash, you can look at the section 6.4 Bash Conditional Expressions of the Bash Reference Manual.
-a file
True if file exists.
-b file
True if file exists and is a block special file.
-c file
True if file exists and is a character special file.
-d file
True if file exists and is a directory.
-e file
True if file exists.
-f file
True if file exists and is a regular file.
-g file
True if file exists and its set-group-id bit is set.
-h file
True if file exists and is a symbolic link.
-k file
True if file exists and its "sticky" bit is set.
[...]
See the documentation cited above for the full list.