retroforth/interfaces/io/io_unix_syscalls.forth
crc 964c5ddce0 move io devices to a separate directory, build as .o files
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2019-01-11 21:51:21 +00:00

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# System Interaction
The `unix:` namespace contains words for interacting with the
host operating system.
~~~
{{
'io:UnixSyscall var
:identify
@io:UnixSyscall n:zero? [
#8 io:scan-for dup n:negative?
[ drop 'IO_DEVICE_TYPE_0008_NOT_FOUND s:put nl ]
[ !io:UnixSyscall ] choose ] if ;
---reveal---
:io:unix-syscall identify @io:UnixSyscall io:invoke ;
}}
~~~
`unix:system` runs another application using the system shell
and returns after execution is completed.
~~~
:unix:system (s-) #0 io:unix-syscall ;
~~~
`unix:fork` forks the current process and returns a process
identifier.
~~~
:unix:fork (-n) #1 io:unix-syscall ;
~~~
This group is used to execute a new process in place of the
current one. These take a program and optionally 1-3 arguments.
They map to the execl() system call.
Example:
'/usr/bin/cal '2 '2019 unix:exec2
~~~
:unix:exec0 (s-) #2 io:unix-syscall ;
:unix:exec1 (ss-) #3 io:unix-syscall ;
:unix:exec2 (sss-) #4 io:unix-syscall ;
:unix:exec3 (ssss-) #5 io:unix-syscall ;
~~~
`unix:exit` takes a return code and exits RRE, returning the
specified code.
~~~
:unix:exit (n-) #6 io:unix-syscall ;
~~~
`unix:getpid` returns the current process identifier.
~~~
:unix:getpid (-n) #7 io:unix-syscall ;
~~~
`unix:wait` waits for a child process to complete. This maps to
the wait() system call.
~~~
:unix:wait (-n) #8 io:unix-syscall ;
~~~
`unix:kill` terminates a process. Takes a process and a signal
to send.
~~~
:unix:kill (nn-) #9 io:unix-syscall ;
~~~
The next two words allow opening and closing pipes. The first,
`unix:popen` takes the name of a program and a file mode and
returns a file handle usable with words in the `file:` namespace.
The second, `unix:pclose` closes the pipe.
~~~
:unix:popen (sn-n) #10 io:unix-syscall ;
:unix:pclose (n-) #11 io:unix-syscall ;
~~~
~~~
:unix:write (sh-) [ dup s:length ] dip #12 io:unix-syscall ;
~~~
`unix:chdir` changes the current working directory to the
specified one.
~~~
:unix:chdir (s-) #13 io:unix-syscall ;
~~~
~~~
:unix:getenv (sa-) #14 io:unix-syscall ;
:unix:putenv (s-) #15 io:unix-syscall ;
~~~
`unix:sleep` pauses execution for the specified number of
seconds.
~~~
:unix:sleep (n-) #16 io:unix-syscall ;
~~~
~~~
:unix:io:n:put (n-) #17 io:unix-syscall ;
:unix:io:s:put (s-) #18 io:unix-syscall ;
~~~