diff options
Diffstat (limited to 'Doc/Zsh/mod_clone.yo')
| -rw-r--r-- | Doc/Zsh/mod_clone.yo | 34 |
1 files changed, 31 insertions, 3 deletions
diff --git a/Doc/Zsh/mod_clone.yo b/Doc/Zsh/mod_clone.yo index 9bb7dc255..1791a6df9 100644 --- a/Doc/Zsh/mod_clone.yo +++ b/Doc/Zsh/mod_clone.yo @@ -1,6 +1,7 @@ -texinode(The clone Module)(The comp1 Module)(The cap Module)(Zsh Modules) -sect(The clone Module) -The tt(clone) module makes available one builtin command: +COMMENT(!MOD!zsh/clone +A builtin that can clone a running shell onto another terminal. +!MOD!) +The tt(zsh/clone) module makes available one builtin command: startitem() findex(clone) @@ -15,5 +16,32 @@ shell, and to the new shell's PID in the original shell. The return value of the builtin is zero in both shells if successful, and non-zero on error. + +The target of tt(clone) should be an unused terminal, such as an unused virtual +console or a virtual terminal created by + +xterm -e sh -c 'trap : INT QUIT TSTP; tty; while :; do sleep 100000000; done' + +Some words of explanation are warranted about this long xterm command +line: when doing clone on a pseudo-terminal, some other session +("session" meant as a unix session group, or SID) is already owning +the terminal. Hence the cloned zsh cannot acquire the pseudo-terminal +as a controlling tty. That means two things: + + the job control signals will go to the sh-started-by-xterm process + group (that's why we disable INT QUIT and TSTP with trap; otherwise + the while loop could get suspended or killed) + + the cloned shell will have job control disabled, and the job + control keys (control-C, control-\ and control-Z) will not work. + +This does not apply when cloning to an bf(unused) vc. + +Cloning to an used (and unprepared) terminal will result in two +processes reading simultaneously from the same terminal, with +input bytes going randomly to either process. + +tt(clone) is mostly useful as a shell built-in replacement for +openvt. ) enditem() |