# $EPIC: exec_command.txt,v 1.3 2006/08/30 21:02:47 sthalik Exp $ ======Synopsis:====== __exec__ [] [] \\ __exec__ -direct \\ __exec__ -name \\ __exec__ -out \\ __exec__ -msg \\ __exec__ -notice \\ __exec__ -in \\ __exec__ -window \\ __exec__ -wintarget \\ __exec__ - \\ __exec__ -close \\ __exec__ -closein \\ __exec__ -line {epic commands} \\ __exec__ -linepart {epic commands} \\ __exec__ -error {epic commands} \\ __exec__ -errorpart {epic commands} \\ __exec__ -end {epic commands} ======Options:====== |-direct |executes commands without spawning a shell | |-name |give the subprocess a (new) logical name | |-out |send subprocess output to your current channel or query | |-msg |send subprocess output to a nick or channel with [[MSG]] | |-notice |send subprocess output to a nick or channel with [[NOTICE]] | |-in |send a text string to the specified subprocess | |-window |redirect subprocess output to the current window | |-wintarget |redirect subprocess output to the specified window | |- |send SIG to the subprocess. \\ Numeric signals are also permitted. | |-close |forcibly kill the subprocess and its children | |-closein |close the input of the process but let it continue. | |-line |run this command for each line of output. | |-linepart |run this command for each partial line of output. | |-error |run this command for each line of STDERR output. | |-errorpart |run this command for each partial line of STDERR output. | |-end |run this command when the process terminates. \\ See comments on -END below. | ======Description:====== __EXEC__ allows you to spawn other processes from within your client, which are naturally treated as child processes. For example, if you wished to check your email without suspending your client (or quitting irc), you could simply __EXEC__ your favorite mail program. Processes can be given unique names, allowing them to be referred to more intuitively than trying to figure out its process id number. Processes can also accept any signal normally available through use of the Unix "kill" command (letting you kill, suspend, etc. any process that accepts such a signal). Process identifiers begin with a "%". Thus, a process named "mail" with pid 0 could be referred to as either "%mail" or "%0". __EXEC__ can take several different flags, each of which allow you to manipulate the subprocess in different ways. At the most basic level, the only argument you really need to give is the external program to run. If no arguments are given at all, a list of any currently running processes is returned. When using the -OUT, -MSG, or -NOTICE flags, output can be sent to the target upon startup of the subprocess, or redirected to it after it's already running by using its process id. Another flag of note, -CLOSE, can be used to shut down renegade subprocesses that simply won't go away (i.e. with their own quit command, with the KILL signal, etc.). This actually just severs the link between the subprocess and the client, so it will die on its own the next time it tries to send data to the client. Something to remember when worried about a shell processing arguments is the -DIRECT flag, which executes the commands without spawning a shell. This can cut down on security risks, and save some memory. The options -LINE, -ERROR, -LINEPART, -ERRORPART and -END all take arguments which must be enclosed in braces "{}" and which are executed for particular kinds of output that the process might give. The $* variable will contain that output when those commands are executed. Note that the -END flag is different from the other flags. When you specify a %process instead of shell commands, the flags you specify become the new options for the currently running process of that name (if possible), replacing the current settings for those options. Specifying a -END flag in this mode is will add to, rather than replace other -END options. ======Examples:====== (Assume that the process used with these examples is the Unix mail program.) To start a process: /exec mail To start a process without a shell interfering: /exec -direct mail To start a process and give it a human-readable name: /exec -name mail mail To send the output of a new subprocess to your current channel or query: /exec -out mail To send the output of a running subprocess to JoeBob with a [[MSG]]: /exec -msg joebob %mail To send the output of a new subprocess to #blah with a [[NOTICE]]: /exec -notice #blah mail To send a text string (command) to a running subprocess: /exec -in %mail ? To send a running subprocess the KILL signal: /exec -kill %mail To forcibly close down a stubborn subprocess that just won't die: /exec -close %mail To rename a process: /exec -name MyMail %mail To make all mail output bold: /exec -line {echo $chr(2)$*} %mail To add more -end commands after the process has started: /exec -end {commands} %mail Which is equivalent to: /wait %process -cmd {commands} ======Aliases:====== When using __EXEC__ with the -IN flag, the functionality is identical to using [[MSG]] to send a message to a process. See [[MSG]] for more information. When using the -END flag, the functionality is identical to using "[[WAIT]] %process -cmd {command}". ======Restrictions:====== Use of external programs from within irc can sometimes be dangerous if you don't know what you're doing. The danger doesn't necessarily lie in the external programs themselves, but rather in any lack of knowledge about them you may have. When all else fails, don't use a command if you don't know what it does. You can explicitly limit your ability to use __EXEC__ in several ways. If [[set SECURITY]] has the 1 bit set, the client will only permit __EXEC__ to be used interactively; using it from within aliases is not allowed. For real security, you can #define RESTRICTED at compile time, which will completely disable __EXEC__. ======Other Notes:====== The available signals that may be sent to a process will vary from system to system.