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Module os

Module os

Overview

The os module contains the functions execute(), rename(), getenv(), remove(), date(), exit(), time(), clock(), tmpname(), environ(), setenv(), setlocale(), difftime(). Most of these functions are described in the Lua manual Chapter 22 The Operating System Library.

Index

Below is a list of all os functions.

Name Use
os.execute() Execute by passing to the shell
os.rename() Rename a file or directory
os.getenv() Get an environment variable
os.remove() Remove a file or directory
os.date() Get a formatted date
os.exit() Exit the program
os.time() Get the number of seconds since the epoch
os.clock() Get the number of CPU seconds since the program start
os.tmpname() Get the name of a temporary file
os.environ() Get a table with all environment variables
os.setenv() Set an environment variable
os.setlocale() Change the locale
os.difftime() Get the number of seconds between two times
os.execute(shell-command)

Execute by passing to the shell.

Parameters:
  • shell-command (string) – what to execute.

Example:

tarantool> os.execute('ls -l /usr')
total 200
drwxr-xr-x   2 root root 65536 Apr 22 15:49 bin
drwxr-xr-x  59 root root 20480 Apr 18 07:58 include
drwxr-xr-x 210 root root 65536 Apr 18 07:59 lib
drwxr-xr-x  12 root root  4096 Apr 22 15:49 local
drwxr-xr-x   2 root root 12288 Jan 31 09:50 sbin
---
...
os.rename(old-name, new-name)

Rename a file or directory.

Parameters:
  • old-name (string) – name of existing file or directory,
  • new-name (string) – changed name of file or directory.

Example:

tarantool> os.rename('local','foreign')
---
- null
- 'local: No such file or directory'
- 2
...
os.getenv(variable-name)

Get environment variable.

Parameters: (string) variable-name = environment variable name.

Example:

tarantool> os.getenv('PATH')
---
- /usr/local/sbin:/usr/local/bin:/usr/sbin
...
os.remove(name)

Remove file or directory.

Parameters: (string) name = name of file or directory which will be removed.

Example:

tarantool> os.remove('file')
---
- true
...
os.date(format-string[, time-since-epoch])

Return a formatted date.

Parameters: (string) format-string = instructions; (string) time-since-epoch = number of seconds since 1970-01-01. If time-since-epoch is omitted, it is assumed to be the current time.

Example:

tarantool> os.date("%A %B %d")
---
- Sunday April 24
...
os.exit()

Exit the program. If this is done on a server instance, then the instance stops.

Example:

tarantool> os.exit()
user@user-shell:~/tarantool_sandbox$
os.time()

Return the number of seconds since the epoch.

Example:

tarantool> os.time()
---
- 1461516945
...
os.clock()

Return the number of CPU seconds since the program start.

Example:

tarantool> os.clock()
---
- 0.05
...
os.tmpname()

Return a name for a temporary file.

Example:

tarantool> os.tmpname()
---
- /tmp/lua_7SW1m2
...
os.environ()

Return a table containing all environment variables.

Example:

tarantool> os.environ()['TERM']..os.environ()['SHELL']
---
- xterm/bin/bash
...
os.setenv(variable-name, variable-value)

Set an environment variable.

Example:

tarantool> os.setenv('VERSION','99')
---
-
...
os.setlocale([new-locale-string])

Change the locale. If new-locale-string is not specified, return the current locale.

Example:

tarantool> require('string').sub(os.setlocale(),1,20)
---
- LC_CTYPE=en_US.UTF-8
...
os.difftime(time1, time2)

Return the number of seconds between two times.

Example:

tarantool> os.difftime(os.time() - 0)
---
- 1486594859
...