Documentation

the default compiling action. checks whether any of the sources files under "~/.xmonad/" is newer than the binary and recompiles XMonad if so.

the default post-compiling action. prints out error log to stderr and pops up a message when the last compilation has failed.

compileUsingShell cmd spawns a new process to run a shell command (shell expansion is applied). The working directory of the shell command is "~/.xmonad/", and the process' stdout and stdout are redirected to "~/.xmonad/xmonad.errors"

prevents an IO action from parallel execution by using a lock file. withFileLock fpath def action checks whether the file indicated by fpath exists. And:

• returns def if the file exists.
• creates fpath, executes the action, and deletes fpath when the action has completed. If action has failed, def will be returned instead.

Note that:

• the action will be protected by safeIO, meaning the lock file will be deleted regardless of any error.
• No check on fpath will be done by this function. Please make sure the lock file does not exist.
• please prevent wrapping the action with same file lock multiple times, in which case the action will never be executed.

withLock def action is the same as withFileLock fpath def action with fpath being "xmonad.${USERNAME}.lock" under your temporary directory. Wrapping an action with more than one withLock will not work.

See also: withFileLock, getTemporaryDirectory, getEffectiveUserName