CODEWITHSUNDEEP
linuxbashshellfilepermissions
Victor Lee
Victor Lee

Reputation: 2658

how bash create a file which only accessed by current bash script process

As I know, the bash script can create and write file to disk path or /dev/shm, but the file was accessed by root or other user. How can I set the file's permission that only accessed by current bash script process? And I will rm this file before exit the bash script.

Upvotes: 0

Views: 598

Answers (1)

Shawn
Shawn

Reputation: 52439

You can redirect a filename to a given descriptor number, and delete the file, and then access it through the descriptor:

#!/usr/bin/env bash

name=$(mktemp)
exec {fd}<>"$name"
rm -f "$name"
echo foo >&$fd
cat </dev/fd/$fd

Using a descriptor that's been opened for both reading and writing with <> is tricky in bash, see Bash read/write file descriptors — seek to start of file for the logic behind that cat line at the end.

If you've never seen the {name}<>filename style redirection before, it automatically assigns an unused descriptor to the file and stores its number in $name.

Upvotes: 1

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