LuaPosix

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

(not working) I maybe running it wrong from interactive lua. But it always exits the interactive session. INPUT

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

OUPUT

• Strings

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

files

(not working) Is only returning a function INPUT

• PATH- Directory

OUPUT

• 0
• nil

bar = require "posix"
bobo = bar.files("/etc/bogus/")
print(bobo)

==fork==(needs more explaining) INPUT

• None

OUPUT If you run this in interactive lua the function will give you a prompt with one more >

> >
bar = require "posix"
bar.fork()
for a=1,10 do print(a) end
--the above runs and then exists the fork

wait

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If you are using this under linux also get