What Is Bourne Shell?

What is bourne shell?

Bourne Shell is the oldest shell. It was written by Stephen Bourne at Bell Laboratories. The Bourne Shell has been the default shell for many UNIX like operating system and root users. It has been a de facto standard in the industry. The Bourne Shell has neither the interactive features, nor the complex programming constructs, of the C and Korn shells.

/bin/sh

Bourne shell is located at /bin/sh

A modified and advanced version may be installed in modern UNIX like operating systems. It may be a symbolic link more feature-rich shell than the Bourne shell.

It is still used to write system initialization scripts located in /etc/rc.d/ or /usr/local/etc/rc.d or /etc/init.d/ scripts.

A Typical Example of /bin/sh Script From FreeBSD Operating System

#!/bin/sh
#
# $FreeBSD: src/etc/rc.d/cron,v 1.7.10.1.4.1 2009/04/15 03:14:26 kensmith Exp $
#
 
# PROVIDE: cron
# REQUIRE: LOGIN cleanvar
# BEFORE: securelevel
# KEYWORD: shutdown
 
. /etc/rc.subr
 
name="cron"
rcvar="`set_rcvar`"
command="/usr/sbin/${name}"
pidfile="/var/run/${name}.pid"
 
load_rc_config $name
if checkyesno cron_dst
then
	cron_flags="$cron_flags -s"
fi
run_rc_command "$1"

Bourne Shell Features

1. Command history feature : No (the ability to store commands in a buffer, then modified and reused)
2. Line editing feature : No ( the ability to modify the current or previous command lines with a text editor)
3. Restricted shells : No ( security feature providing a controlled environment with limited capabilities)

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