From ea8d3ab3e41f600a3564a8d92bd630468a1af036 Mon Sep 17 00:00:00 2001 From: Clinton Bunch Date: Fri, 22 Mar 2019 17:11:19 -0500 Subject: 44156 (tweaked): zsh/system: Add note about potential flock side-effects (Minor adjustments to wording and formatting) --- Doc/Zsh/mod_system.yo | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'Doc') diff --git a/Doc/Zsh/mod_system.yo b/Doc/Zsh/mod_system.yo index a27bab47f..3a85e760f 100644 --- a/Doc/Zsh/mod_system.yo +++ b/Doc/Zsh/mod_system.yo @@ -177,8 +177,11 @@ locked by opening a file descriptor to the file and applying a lock to the file descriptor. The lock terminates when the shell process that created the lock exits; it is therefore often convenient to create file locks within subshells, since the lock is automatically released when -the subshell exits. Status 0 is returned if the lock succeeds, else -status 1. +the subshell exits. Note that use of the tt(print) builtin with the +tt(-u) option will, as a side effect, release the lock, as will redirection +to the file in the shell holding the lock. To work around this use a +subshell, e.g. `tt((print message) >> )var(file)'. Status 0 is +returned if the lock succeeds, else status 1. In the second form the file descriptor given by the arithmetic expression var(fd_expr) is closed, releasing a lock. The file descriptor -- cgit 1.4.1