paclock1

Usage

Overview

Safe locking and unlocking of the ALPM database using identity keys for scripts.

Options

--config=path

Set an alternate configuration file path.

--lockfile=path

Set an alternate lock file path.

--root=path

Set an alternate installation root.

--sysroot=path

Set an alternate system root. See pacutils-sysroot(7).

--lock

Lock the database (default).

--unlock

Unlock the database.

--run

Treat "argv" as a command to run with the database locked. If the command returns non-zero, the lock file will be left in place to indicate an error unless --fail-ok is used.

--fail-ok

Unlock the database after running a command with --run even if the command returns non-zero. Generally, the database should be left locked if it may be in an inconsistent to indicate that it may need to be repaired. This flag is intended primarily for read-only operations.

--print

Write the lock file path to stdout and exit without modifying the lock file.

--no-check-keys

Skip checking for an identity key match before unlocking.

--enoent-ok

Do not treat a non-existent lock file as an error when unlocking.

--key=identity

An identifier to write to the lock file. By default, --unlock will only operate if the lock file was previously locked with the same key. Defaults to the hostname followed by a colon and the process id of the caller (for example: "localhost:123").

--help

Display usage information and exit.

--version

Display version information and exit.

Examples

The system configuration that paclock relies on to construct the default lock file path and identity key may change between invocations. To ensure consistency, scripts should explicitly provide the path and key to use each time paclock is called.

 #!/bin/bash
 lock_file="$(paclock --print)"
 lock_key="myapp:$(hostname):$$"
 paclock --lockfile="$lock_file" --key="$lock_key" || exit 1
 echo "do stuff here"
 paclock --lockfile="$lock_file" --key="$lock_key" --unlock || exit 1

Run a command lacking native lock support:

 paclock --run -- paccache --dryrun --verbose