— Function: sb-ext:posix-getenv name

Return the "value" part of the environment string "name=value" which corresponds to name, or nil if there is none.

— Function: sb-ext:run-program program args &key env environment wait search pty input if-input-does-not-exist output if-output-exists error if-error-exists status-hook

run-program creates a new Unix process running the Unix program found in the file specified by the program argument. args are the standard arguments that can be passed to a Unix program. For no arguments, use nil (which means that just the name of the program is passed as arg 0).

run-program will return a process structure. See the cmu Common Lisp Users Manual for details about the process structure.

Notes about Unix environments (as in the :environment and :env args):

• The sbcl implementation of run-program, like Perl and many other programs, but unlike the original cmu cl implementation, copies the Unix environment by default.
• Running Unix programs from a setuid process, or in any other situation where the Unix environment is under the control of someone else, is a mother lode of security problems. If you are contemplating doing this, read about it first. (The Perl community has a lot of good documentation about this and other security issues in script-like programs.)

The &key arguments have the following meanings:

:environment

a list of SIMPLE-BASE-STRINGs describing the new Unix environment (as in "man environ"). The default is to copy the environment of the current process.

:env

an alternative lossy representation of the new Unix environment, for compatibility with cmu cl

:search

Look for program in each of the directories along the $PATH environment variable. Otherwise an absolute pathname is required. (See also FIND-EXECUTABLE-IN-SEARCH-PATH)

:wait

If non-NIL (default), wait until the created process finishes. If nil, continue running Lisp until the program finishes.

:pty

Either t, nil, or a stream. Unless nil, the subprocess is established under a pty. If :pty is a stream, all output to this pty is sent to this stream, otherwise the process-pty slot is filled in with a stream connected to pty that can read output and write input.

:input

Either t, nil, a pathname, a stream, or :stream. If t, the standard input for the current process is inherited. If nil, /dev/null is used. If a pathname, the file so specified is used. If a stream, all the input is read from that stream and send to the subprocess. If :stream, the process-input slot is filled in with a stream that sends its output to the process. Defaults to nil.

:if-input-does-not-exist (when :input is the name of a file)

can be one of: :error to generate an error :create to create an empty file nil (the default) to return nil from run-program

:output

Either t, nil, a pathname, a stream, or :stream. If t, the standard output for the current process is inherited. If nil, /dev/null is used. If a pathname, the file so specified is used. If a stream, all the output from the process is written to this stream. If :stream, the process-output slot is filled in with a stream that can be read to get the output. Defaults to nil.

:if-output-exists (when :output is the name of a file)

can be one of: :error (the default) to generate an error :supersede to supersede the file with output from the program :append to append output from the program to the file nil to return nil from run-program, without doing anything

:error and :if-error-exists

Same as :output and :if-output-exists, except that :error can also be specified as :output in which case all error output is routed to the same place as normal output.

:status-hook

This is a function the system calls whenever the status of the process changes. The function takes the process as an argument.

— Function: sb-ext:process-p object

t if object is a process, nil otherwise.

— Function: sb-ext:process-input instance

The input stream of the process or nil.

— Function: sb-ext:process-output instance

The output stream of the process or nil.

— Function: sb-ext:process-error instance

The error stream of the process or nil.

— Function: sb-ext:process-alive-p process

Return t if process is still alive, nil otherwise.

— Function: sb-ext:process-status process

Return the current status of process. The result is one of :running, :stopped, :exited, or :signaled.

— Function: sb-ext:process-wait process &optional check-for-stopped

Wait for process to quit running for some reason. When check-for-stopped is t, also returns when process is stopped. Returns process.

— Function: sb-ext:process-exit-code instance

The exit code or the signal of a stopped process.

— Function: sb-ext:process-core-dumped instance

t if a core image was dumped by the process.

— Function: sb-ext:process-close process

Close all streams connected to process and stop maintaining the status slot.

— Function: sb-ext:process-kill process signal &optional whom

Hand signal to process. If whom is :pid, use the kill Unix system call. If whom is :process-group, use the killpg Unix system call. If whom is :pty-process-group deliver the signal to whichever process group is currently in the foreground.