Beyond Linux® From Scratch (systemd Edition) - Version r12.0-816

Chapter 7. Shells

Dash-0.5.12

Introduction to Dash

Dash is a POSIX compliant shell. It can be installed as /bin/sh or as the default shell for either root or a second user with a userid of 0. It depends on fewer libraries than the Bash shell and is therefore less likely to be affected by an upgrade problem or disk failure. Dash is also useful for checking that a script is completely compatible with POSIX syntax.

[Note]

Note

Development versions of BLFS may not build or run some packages properly if LFS or dependencies have been updated since the most recent stable versions of the books.

Package Information

Dash Dependencies

Optional

libedit (command line editor library)

Installation of Dash

Install Dash by running the following commands: 

./configure --bindir=/bin --mandir=/usr/share/man &&
make

This package does not come with a test suite.

Now, as the root user: 

make install

If you would like to make dash the default sh, recreate the /bin/sh symlink as the root user:

[Note]

Note

If you create the symbolic link from dash to sh, you will need to reset the link to bash to build LFS. 

ln -svf dash /bin/sh

Command Explanations

--bindir=/bin: This parameter places the dash binary into the root filesystem.

--with-libedit: To compile Dash with libedit support.

Configuring Dash

Config Files

Dash sources /etc/profile and ~/.profile

Configuration Information

Update /etc/shells to include the Dash shell by issuing the following command as the root user: 

cat >> /etc/shells << "EOF"
/bin/dash
EOF

Contents

Installed Program: dash
Installed Libraries: None
Installed Directories: None

Short Description

dash

is a POSIX compliant shell