LuaPosix

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Revision as of 19:57, 10 November 2007 by Nangel (talk | contribs) (→‎exec)
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Lua Posix

This is a list of the Lua Posix functions. Included is helpful snipets of code. Install lua posix. To get this list do:

bar = require "posix"
for a in pairs(bar) do print(a) end

access

INPUT

  • Path- file or directory path that wants to be checked
  • Permission - what permissions do you want to check
    • "r" = read
    • "w" = write
    • "x" = execute
    • "f" = all permissions? not sure

OUPUT

  • string - 0 for success, nil for failure if done
bar = require "posix"
temp = bar.access("/etc/passwd", "w")
print(temp)

Will give more information like

bar = require "posix"
print(bar.access("/etc/passwd", "w"))
--If nil will give back the error too
nil     /etc/passwd: Permission denied  13

chdir

INPUT

  • Path - where do you want to change directory to

OUPUT

  • 0 if success
    • nil if failed
bar = require "posix"
bar.chdir("/etc/")
--print(bar.getcwd()) to see where you are

0 if success, nil if failure. If you

print(bar.chdir("/var/lob"))
-- it will print the system error message also
nil     /var/lob: No such file or directory     2

chmod

INPUT

  • PATH - where is the file or directory
    • MODE - what mode to you want to change on the file

OUPUT

  • string - 0 if sucess, nil failure
bar = require "posix"
bar.chmod("/etc/passwd", "a=rwx")
--looks like you need to use the ugoa format for this, not numbers

chown

INPUT

  • Path-location of file or directory
  • UID - User id number
  • GID - Group id number

OUPUT

  • String - 0 is success and nil for failure
bar = require "posix"
print(bar.chown("/etc/passwd",100,200)
--above will give back nil. Since we printed it will also give back the system errors.

ctermid

INPUT

  • NONE- DISPLAYS the terminal id

OUTPUT

  • String with the terminal id
bar = require "posix"
print(bar.ctermid())

dir

Directory listing INPUT

  • PATH - directory

OUTPUT

  • TABLE - table with the file name contents of the directory
    • Failure returns a nil value
bar = require "posix"
bobo = bar.dir("/var/log")
for a,b in ipairs(bobo) do print(b) end
-- the bobo table will output all the file names in /var/log/

errno

Display the error information

INPUT

  • NONE

OUPUT

  • Success, or Error message
bar = require "posix"
a,b = bar.dir("/var/foo"), bar.errno()
print(a,b)
-- a will be nil or 0, b will be No such file or directory or Success

exec

Replaces the running process with the command specified. Command line arguments are given as additional arguments. (To start a sub process, you probably want fork+exec, not just exec.)

INPUT

  • PATH-Location of binary
  • ARGs-options to pass to binary

OUTPUT

  • Strings
bar = require "posix"
bobo = bar.exec("/bin/ls", "-l", "/etc/")

files

Returns an interator function that loops over each file in the given directory

INPUT

  • PATH- Directory

OUPUT

require "posix"
for name in posix.files("/etc") do
    print (name)
end

fork

INPUT

  • None

OUTPUT returns: -1 on error, 0 to the child process, and the pid of the child to the parent.

require("posix")

print ("parent: my pid is: " .. posix.getpid("pid")) 

local pid = posix.fork () 

if ( pid == -1 ) then
        print ("parent: The fork failed.")
elseif ( pid == 0 ) then
        print ("child: Hello World! I am pid: " .. posix.getpid("pid") )
        print ("child: I'll sleep for 1 second ... ")
        posix.sleep(1)
        print ("child: Good bye");
else
        print ("parent: While the child sleeps, I'm still running.")
        print ("parent: waiting for child (pid:" .. pid .. ") to die...")
        posix.wait(pid)
        print ("parent: child died, but I'm still alive.")
        print ("parent: Good bye")
end
parent: my pid is: 11050
child: Hello World! I am pid: 11051
child: I'll sleep for 1 second ... 
parent: While the child sleeps, I'm still running.
parent: waiting for child (pid:11051) to die...
child: Good bye
parent: child died, but I'm still alive.
parent: Good bye

getcwd

INPUT

  • NONE

OUTPUT

  • String- contents of which is the current working directory
bar = require "posix"
print(bar.getcwd())

getenv

INPUT

  • NONE

OUPUT

  • Table - Current Environment settings
bar = require "posix"
bobo = bar.getenv()
for a,b in pairs(bobo) do print(b) end
-- Varible - Value

getgroup

INPUT

  • GID, or groupname

OUPUT

  • TABLE -contents of which hold the group name,gid, and users
bar = require "posix"
bobo = bar.getgroup(1000)
for a,b in pairs(bobo) do print(a,b) end
--if you use pairs then bobo will print also the name and gid or the group
--if you use ipairs then just the group members
1 user1
2 user2
name wheel
gid 1

getlogin

Couldn't get it to work

INPUT

  • NONE

OUPUT

  • UNKNOWN

getpassword

INPUT

  • NAME or UID

OUPUT

  • TABLE- values from /etc/passwd

uid,name,gid,password,gecos,dir,shell

bar = require "posix"
bobo = bar.getpasswd("root")
for a,b in pairs(bobo) do print(a,b) end
--uid 0
--name root
--gid 0
--passwd x
--gecos root
--dir /root/
--shell /bin/bash

getprocessid

INPUT

  • Selector - either [egid,euid,gid,uid,pgrp,pid,ppid,NULL]

OUPUT

  • Number that matches the current process and the selector
bar = require "posix"
print(bar.getprocessid("gid"))
18456 
--it just printed the current process id for the script or interactive lua.


Is there a version difference here? AL 1.7.7 calls this "getpid" Nangel

kill

INPUT

  • PID- process identifier
  • Signal- to send to the process

OUPUT

bar = require "posix"
--kill your current process
bobo = bar.getprocessid("pid")
bar.kill(bobo,9)
---Signals looks to be the number signals accepted in Unix

link

Hard Links INPUT

  • Oldpath-
  • Newpath-

'OUTPUT If you want output 0 sucess, nil errors

bar = require "posix"
bobo = bar.link("/etc/passwd", "testfile")
-- 0 for success, nil for errors

mkdir

INPUT

  • PATH-path to new dir

OUTPUT If you are looking for output-

  • 0 for success
  • nil for failure
bar = require "posix"
bar.mkdir("/home/user/bobo")
--set the above to a variable to get output

mkfifo

INPUT

  • PATH- where to make the fifo

patchconf

putenv

readlink

rmdir

setgid

setuid

sleep

stat

symlink

sysconf

times

ttyname

umask

uname

utime

wait


If you are using this under linux also get

setenv

unsetenv