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

#!/bin/bash

 file="./file"

if [ -e $file ]; then

echo "File exists"

else 

echo "File does not exists"

fi 

Similarly for example we can use while loop to check if file does not exists. This script will sleep until file does exists. Note bash negator "!" which negates the -e option.

#!/bin/bash

 

while [ ! -e myfile ]; do

# Sleep until file does exists/is created

sleep 1

done