Various methods exists to create a random temporary file name. This is useful if your application/shell scripting needs temporary unique file names.
Method #1: Use of $RANDOM bash shell variable
1) At shell prompt type command:
# echo $RANDOM
You will get random value every time. This variable can be use to create unique file name as demonstrated by createtempfiles.bash script.
1) Download/view createtempfiles.bash script
2) Save the script to your computer and execute it as follows:
$ chmod +x random1.bash
Use this method if your script needs more than two temporary files.
Method # 2 Use of $$ variable
This is old and classic method. $$ shell variable returns the current running process this can be use to create unique temporary file as demonstrated in following script:
#!/bin/bash # TFILE="/tmp/$(basename $0).$$.tmp" ls > $TFILE echo "See diretory listing in $TFILE"
Save the script and execute as follows:
$ chmod +x random2.bash
$ ./ random2.bash
Use this method if your script needs only ONE temporary file.
Method # 3 Use of mktemp or tempfile utility
As name suggest both makes unique temporary filename. Just type mktemp at shell prompt to create it:
Make a unique temporary directory instead of a file using –d option to both of them
$ mktemp –d
$ tempfile –d
Both mktemp or tempfile provides the shell scripts facility to use temporary files in safe manner hence it is highly recommended to use them.