spawn

A expect like lua module fork from lua-gdb package.

You can download original lua-gdb package here [http://mysite.mweb.co.za/residents/sdonovan/lua/lua-gdb.zip]

Build and install

Please compile and install it by copy and paste:

$gcc -Wall -shared -fPIC -I/usr/local/include/lua51 spawn.c -o spawn.so -llua-5.1 -lutil
$cp spawn.so /usr/local/lib/lua/5.1/

NOTE:

• lexecpt.lua is not working fine with whis version of spawn, just see see:)
• This version has been tested only on FreeBSD 10.0 and centos 6.3 up to now.

Functions

---

spawn.setbuffsize([buffsize])

Sets default buffer size of IO, always returns the default buffer size.

---

spawn.setterm([mode])

Sets Term mode of process, returns current Term mode or nil if mode is invaild.

Mode is alternative of below:

• "raw"

   Raw INPUT/OUTPUT, this mode useful in lua script daemon.
  

• "sane"

   See stty(1), may need setting windows size, **NOT TEST** in lua script daemon yet, this mode useful in fork process like bash.
  

• "keep"

   Keep Term the same with INPUT Term, this mode make auto input and print in current window easy.
  

---

spawn.open(process)

This function forks a process. It returns a new process handle. Process is default opened with block mode and 2048 of buffersize.

---

spawn.sleep(time)

Sleep, time can be 1(s) "1"(s) "1s"(s) "1ms"(ms) "1us"(us).

---

proc:setnonblock(mode)

Sets pty FD to nonblock if mode is true. Returns current flags or nil if failed.

---

proc:setdelay(us)

Sets nonblock mode read interval, in unit of microsecond.

---

proc:reads([size])

Try reads size bytes from pty. If in nonblock mode, loop reads in interval of us. Returns string of at most min(buffsize, size) length or nil if any error occurs.

NOTE: If a not EAGAIN error happened, preform a __gc calling, this may only occur when pty was closed.

Return vaules:

.----------------------------------.
| Condition     | Block | NonBlock |
|---------------|-------|----------|
| No data ready | -     | nil      |
| EOF           | ""    | ""       |
| IO error      | nil   | nil      |
`----------------------------------'

---

proc:writes(string)

Writes string to pty. Returns write syscall return value.

---

proc:kill([sig])

Sends a sig to process or sends SIGINT if sig is not presented.

---

proc:wait([mode])

Waits for a process to exit, nonblock if mode is true. Returns pid or 0 if failed.

NOTE: This function also clear userdata. Marks process closed

---

proc:closepty()

Closes FD of pty, process may exits after FD was closed.

NOTE: You may call proc:wait to collect process exit status, but __gc can also do it.

---

proc:isdead()

Checks process is dead or not. Returns true if dead and vice versa.

---

proc:__gc()

Perform follow actions:

• Sends SIGKILL to process.
• Closes pty.
• Waits exit status of any child process in nonblock mode, repeat 5 times.

---

proc:version()

Prints version.

---

Example

>> package.cpath="./?.so"
>> require"spawn"
{
    open = function, setbuffsize = function, setterm = function,
    version = function
}
>> spawn.setterm"keep"
"keep"
>> spawn.setbuffsize(50)
50
>> x=spawn.open"bash"
>> x:setnonblock(1)
6
>> x:reads()
nil "Resource temporarily unavailable"
>> x:writes"yes\n"
4
>> x:reads()
"yes\r\n"
>> x:reads()
"[chk@NUC ~/spawn]$ yes\r\n"
>> x:reads()
"y\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r"
>> x:reads()
"\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny"
>> x:reads()
"\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\ny\r\n"
>> x:writes"^C"
1
>> x:reads()
"^C\r\n"
>> x:reads()
"\r\n"
>> x:reads()
"[chk@NUC ~/spawn]$ "
>> x:reads()
nil "Resource temporarily unavailable"
>> x:closepty()
>> x:wait(1)
29674
>> x
proc (closed)

License

None

Contact

chk.jxcn#gmail.com