1 ! Copyright (C) 2007, 2008 Slava Pestov.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: help.markup help.syntax quotations kernel io io.files
7 ARTICLE: "io.launcher.command" "Specifying a command"
8 "The " { $snippet "command" } " slot of a " { $link process } " can contain either a string or a sequence of strings. In the first case, the string is processed in an operating system-specific manner. In the second case, the first element is a program name and the remaining elements are passed to the program as command-line arguments." ;
10 ARTICLE: "io.launcher.detached" "Running processes in the background"
11 "By default, " { $link run-process } " waits for the process to complete. To run a process without waiting for it to finish, set the " { $snippet "detached" } " slot of a " { $link process } ", or use the following word:"
12 { $subsections run-detached } ;
14 ARTICLE: "io.launcher.environment" "Setting environment variables"
15 "The " { $snippet "environment" } " slot of a " { $link process } " contains an association mapping environment variable names to values. The interpretation of environment variables is operating system-specific."
17 "The " { $snippet "environment-mode" } " slot controls how the environment of the current Factor instance is composed with the value of the " { $snippet "environment" } " slot:"
23 "The default value is " { $link +append-environment+ } "." ;
25 ARTICLE: "io.launcher.redirection" "Input/output redirection"
26 "On all operating systems, the default input/output/error streams can be redirected."
28 "To specify redirection, set the " { $snippet "stdin" } ", " { $snippet "stdout" } " and " { $snippet "stderr" } " slots of a " { $link process } " to one of the following values:"
30 { { $link f } " - default value; the stream is either inherited from the current process, or is a " { $link <process-stream> } " pipe" }
31 { { $link +closed+ } " - the stream is closed; reads will return end of file and writes will fails" }
32 { { $link +stdout+ } " - a special value for the " { $snippet "stderr" } " slot only, indicating that the standard output and standard error streams should be merged" }
33 { "a path name - the stream is sent to the given file, which must exist for input and is created automatically on output" }
34 { "an " { $link appender } " wrapping a path name - output is sent to the end given file, as with " { $link <file-appender> } }
35 { "a file stream or a socket - the stream is connected to the given Factor stream, which cannot be used again from within Factor and must be closed after the process has been started" }
38 ARTICLE: "io.launcher.priority" "Setting process priority"
39 "The priority of the child process can be set by storing one of the below symbols in the " { $snippet "priority" } " slot of a " { $link process } " tuple:"
41 { $link +lowest-priority+ }
42 { $link +low-priority+ }
43 { $link +normal-priority+ }
44 { $link +high-priority+ }
45 { $link +highest-priority+ }
47 "The default value is " { $link f } ", which denotes that the child process should inherit the current process priority." ;
50 { $description "Possible value for the " { $snippet "stdin" } ", " { $snippet "stdout" } ", and " { $snippet "stderr" } " slots of a " { $link process } "." } ;
53 { $description "Possible value for the " { $snippet "stderr" } " slot of a " { $link process } "." } ;
56 { $class-description "An object representing a file to append to. Instances are created with " { $link <appender> } "." } ;
59 { $values { "path" "a pathname string" } { "appender" appender } }
60 { $description "Creates an object which may be stored in the " { $snippet "stdout" } " or " { $snippet "stderr" } " slot of a " { $link process } " instance." } ;
62 HELP: +prepend-environment+
63 { $description "Possible value of " { $snippet "environment-mode" } " slot of a " { $link process } "."
65 "If this value is set, the child process environment consists of the value of the " { $snippet "environment" } " slot together with the current environment, with entries from the current environment taking precedence."
67 "This is used in situations where you want to spawn a child process with some default environment variables set, but allowing the user to override these defaults by changing the environment before launching Factor." } ;
69 HELP: +replace-environment+
70 { $description "Possible value of " { $snippet "environment-mode" } " slot of a " { $link process } "."
72 "The child process environment consists of the value of the " { $snippet "environment" } " slot."
74 "This is used in situations where you want full control over a child process environment, perhaps for security or testing." } ;
76 HELP: +append-environment+
77 { $description "Possible value of " { $snippet "environment-mode" } " slot of a " { $link process } "."
79 "The child process environment consists of the current environment together with the value of the " { $snippet "environment" } " key, with entries from the " { $snippet "environment" } " key taking precedence."
81 "This is used in situations where you want a spawn child process with some overridden environment variables." } ;
83 ARTICLE: "io.launcher.timeouts" "Process run-time timeouts"
84 "The " { $snippet "timeout" } " slot of a " { $link process } " can be set to a " { $link duration } " specifying a maximum running time for the process. If " { $link wait-for-process } " is called and the process does not exit before the duration expires, it will be killed." ;
87 { $values { "process" process } { "env" "an association" } }
88 { $description "Combines the current environment with the value of the " { $snippet "environment" } " slot of the " { $link process } " using the " { $snippet "environment-mode" } " slot." } ;
90 HELP: current-process-handle
91 { $values { "handle" "a process handle" } }
92 { $description "Returns the handle of the current process." } ;
95 { $values { "process" process } { "handle" "a process handle" } }
96 { $contract "Launches a process." }
97 { $notes "User code should call " { $link run-process } " instead." } ;
100 { $values { "desc" "a launch descriptor" } { "process" process } }
101 { $description "Launches a process. The object can either be a string, a sequence of strings or a " { $link process } ". See " { $link "io.launcher.descriptors" } " for details." }
102 { $notes "The output value can be passed to " { $link wait-for-process } " to get an exit code." } ;
105 { $values { "desc" "a launch descriptor" } { "process" process } }
106 { $contract "Launches a process without waiting for it to complete. The object can either be a string, a sequence of strings or a " { $link process } ". See " { $link "io.launcher.descriptors" } " for details." }
108 "This word is functionally identical to passing a " { $link process } " to " { $link run-process } " having the " { $snippet "detached" } " slot set."
110 "The output value can be passed to " { $link wait-for-process } " to get an exit code."
114 { $values { "code" "an exit status" } }
115 { $description "Throws a " { $link process-failed } " error." }
116 { $error-description "Thrown by " { $link try-process } " if the process exited with a non-zero status code." } ;
119 { $values { "desc" "a launch descriptor" } }
120 { $description "Launches a process and waits for it to complete. If it exits with a non-zero status code, throws a " { $link process-failed } " error." } ;
122 { run-process try-process run-detached } related-words
125 { $values { "process" process } }
126 { $description "Kills a running process. Does nothing if the process has already exited." } ;
129 { $values { "handle" "a process handle" } }
130 { $contract "Kills a running process." }
131 { $notes "User code should call " { $link kill-process } " instead." } ;
134 { $class-description "A class representing a process. Instances are created by calling " { $link <process> } "." } ;
137 { $values { "process" process } }
138 { $description "Creates a new, empty process. It must be filled in before being passed to " { $link run-process } "." } ;
140 HELP: <process-stream>
142 { "desc" "a launch descriptor" }
143 { "encoding" "an encoding descriptor" }
144 { "stream" "a bidirectional stream" } }
145 { $description "Launches a process and redirects its input and output via a pair of pipes which may be read and written as a stream with the given encoding." } ;
147 HELP: <process-reader>
149 { "desc" "a launch descriptor" }
150 { "encoding" "an encoding descriptor" }
151 { "stream" "an input stream" } }
152 { $description "Launches a process and redirects its output via a pipe which may be read as a stream with the given encoding." } ;
154 HELP: <process-writer>
156 { "desc" "a launch descriptor" }
157 { "encoding" "an encoding descriptor" }
158 { "stream" "an output stream" }
160 { $description "Launches a process and redirects its input via a pipe which may be written to as a stream with the given encoding." } ;
162 HELP: with-process-stream
164 { "desc" "a launch descriptor" }
165 { "encoding" "an encoding descriptor" }
168 { $description "Launches a process and redirects its input and output via a pair of pipes. The quotation is called with " { $link input-stream } " and " { $link output-stream } " rebound to these pipes." } ;
170 HELP: with-process-reader
172 { "desc" "a launch descriptor" }
173 { "encoding" "an encoding descriptor" }
176 { $description "Launches a process and redirects its output via a pipe. The quotation is called with " { $link input-stream } " and " { $link output-stream } " rebound to this pipe." } ;
178 HELP: with-process-writer
180 { "desc" "a launch descriptor" }
181 { "encoding" "an encoding descriptor" }
184 { $description "Launches a process and redirects its input via a pipe. The quotation is called with " { $link input-stream } " and " { $link output-stream } " rebound to this pipe." } ;
186 HELP: wait-for-process
187 { $values { "process" process } { "status" object } }
188 { $description "If the process is still running, waits for it to exit, otherwise outputs the status code immediately. Can be called multiple times on the same process." }
189 { $notes "The status code is operating system specific; it may be an integer, or another object (the latter is the case on Unix if the process was killed by a signal). However, one cross-platform behavior code can rely on is that a status code of 0 indicates success." } ;
191 ARTICLE: "io.launcher.descriptors" "Launch descriptors"
192 "Words which launch processes can take either a command line string, a sequence of command line arguments, or a " { $link process } "."
194 "Strings and string arrays are wrapped in a new empty " { $link process } " with the " { $snippet "command" } " slot set. This covers basic use-cases where no launch parameters need to be set."
196 "A " { $link process } " instance can be created directly and passed to launching words for more control. It must be a fresh instance which has never been spawned before. To spawn a process several times from the same descriptor, " { $link clone } " the descriptor first." ;
198 ARTICLE: "io.launcher.lifecycle" "The process lifecycle"
199 "A freshly instantiated " { $link process } " represents a set of launch parameters."
204 "Words for launching processes take a fresh process which has never been started before as input, and output a copy as output."
205 { $subsections process-started? }
206 "The " { $link process } " instance output by launching words contains all original slot values in addition to the " { $snippet "handle" } " slot, which indicates the process is currently running."
207 { $subsections process-running? }
208 "It is possible to wait for a process to exit:"
209 { $subsections wait-for-process }
210 "A running process can also be killed:"
211 { $subsections kill-process } ;
213 ARTICLE: "io.launcher.launch" "Launching processes"
214 "Launching processes:"
220 "Redirecting standard input and output to a pipe:"
226 "Combinators built on top of the above:"
233 ARTICLE: "io.launcher.examples" "Launcher examples"
234 "Starting a command and waiting for it to finish:"
236 "\"ls /etc\" run-process"
238 "Starting a program in the background:"
240 "{ \"emacs\" \"foo.txt\" } run-detached"
242 "Running a command, throwing an exception if it exits unsuccessfully:"
244 "\"make clean all\" try-process"
246 "Running a command, throwing an exception if it exits unsuccessfully or if it takes too long to run:"
249 " \"make test\" >>command"
250 " 5 minutes >>timeout"
253 "Running a command, throwing an exception if it exits unsuccessfully, and redirecting output and error messages to a log file:"
256 " \"make clean all\" >>command"
257 " \"log.txt\" >>stdout"
261 "Running a command, appending error messages to a log file, and reading the output for further processing:"
263 "\"log.txt\" ascii <file-appender> ["
266 " \"report\" >>command"
267 " ascii <process-reader> stream-lines sort reverse [ print ] each"
271 ARTICLE: "io.launcher" "Operating system processes"
272 "The " { $vocab-link "io.launcher" } " vocabulary implements cross-platform process launching."
274 "io.launcher.examples"
275 "io.launcher.descriptors"
280 "io.launcher.lifecycle"
281 "io.launcher.command"
282 "io.launcher.detached"
283 "io.launcher.environment"
284 "io.launcher.redirection"
285 "io.launcher.priority"
286 "io.launcher.timeouts"