open process
Type
command
Summary
Starts a program.
Syntax
open [elevated] process <appName> [for [[{<encoding>] text | binary}] {read | write | update | neither}]
Description
Use the open process command to start up a process you want to either send data to or get data from or both.
Usually, you should use the open process command only to start up programs that run in the background, without any user interaction. When you are finished with the process, use the close process command to cause it to exit.
You can optionally specify either text or binary mode. If you specify text mode, when you use the write to process command, any line feed and return characters are translated to the appropriate end-of-line marker for the current operating system before being written to the process. (The end-of-line marker on Mac OS and OS X systems is a return character; on Unix, a line feed; on Windows, a CRLF.) If you specify binary mode, return and line feed characters are not translated. If you don't specify a mode, the process is opened in text mode.
Use the read form to open the process for reading. If the process is opened for reading, you can use the read from process command to examine its output, but you can't send data to it.
Use the write form to open the process for writing. If the process is opened for writing, you can use the write to process command to send input data to it.
Use the update form to open the file for both reading and writing. If the file is opened for update, you can use both the read from process and write to process commands to send input to it or get output from it.
Use the neither form to run the process without reading data from it or sending data to it. (Using this form is equivalent to using the launch command to start up a program.) Processes opened with the neither form will quit automatically when finished running.
When you quit the application, processes opened with the read, write, or update forms are quit automatically.
On OS X systems, you can use the open process command to start up an application, but not a Unix process. To work with a Unix process, use the shell func instead.
The possibility of choosing an encoding when opening a process for a text operation was added in 7.0. It follows the encodings available in the functions textEncode and textDecode.
Parameters
| Name | Type | Description |
|---|---|---|
appName | The location and name of the program you want to open. You can run only one instantiation of a given program at one time. The appName can be any program on the system. | |
encoding | enum | the encoding to be used
|
Examples
open process "/usr/bin/snapfile"
open process it for read
command startSlave pProcess
open process pProcess for text update
send "monitorSlave pProcess" to me in 50 millisecs
end startSlave
Related
property: hideConsoleWindows
command: kill, close process, read from process, write to process
control structure: exit
function: screenName, textDecode
glossary: command, OS X, Windows, Mac OS, Unix, background, process
keyword: characters
Compatibility and Support
Introduced
LiveCode 1.0
OS
mac
windows
linux
Platforms
desktop