How do I write a shell script to install a list of applications?

I would assume the script would look something like this:

#!/bin/sh
apt-get update  # To get the latest package lists
apt-get install <package name> -y
#etc.

Just save that as something like install_my_apps.sh, change the file's properties to make it executable, and run it from the command line as root.

(Edit: The -y tells apt-get not to prompt you and just get on with installing)

Well, according to your question the easiest script would be:

#!/bin/sh
LIST_OF_APPS="a b c d e"

aptitude update
aptitude install -y $LIST_OF_APPS

However you could also enter aptitude update && aptitude install -y a b c d e. So maybe your question is missing the crucial point here. If there are some further requirements it would be nice to explain them.

Just create a list of apps in a file, example.list, and run

cat example.list | xargs sudo apt-get -y install

#!/bin/bash

set -eu -o pipefail # fail on error and report it, debug all lines

sudo -n true
test $? -eq 0 || exit 1 "you should have sudo privilege to run this script"

echo installing the must-have pre-requisites
while read -r p ; do sudo apt-get install -y $p ; done < <(cat << "EOF"
    perl
    zip unzip
    exuberant-ctags
    mutt
    libxml-atom-perl
    postgresql-9.6
    libdbd-pgsql
    curl
    wget
    libwww-curl-perl
EOF
)

echo installing the nice-to-have pre-requisites
echo you have 5 seconds to proceed ...
echo or
echo hit Ctrl+C to quit
echo -e "\n"
sleep 6

sudo apt-get install -y tig

Explanation:

• set -eu -o pipefail command:

  Command elements	Explanation
  set	Modify how the shell environment operates
  -u	If a variable does not exist, report the error and stop (e.g., unbound variable)
  -e	Terminate whenever an error occurs (e.g., command not found)
  -o pipefail	If a sub-command fails, the entire pipeline command fails, terminating the script (e.g., command not found)

  If this script encounters any errors, it will fail and exit.

  Ref: https://www.tutorialdocs.com/article/set-command-in-bash.html

• sudo -n true command:

  Command elements	Explanation
  sudo	Run as superuser
  -n	Non-interactive. Prevents sudo from prompting for a password. If one is required, sudo displays an error message and exits
  true	Builtin command that returns a successful (zero) exit status

  Run as a superuser and do not ask for a password. Exit status as successful.

  Ref: https://linux.die.net/man/8/sudo, https://linux.die.net/abs-guide/internal.html

• test $? -eq 0 || exit 1 "you should have sudo privilege to run this script" command:

  Command elements	Explanation
  test	Takes an expression as an argument, evaluates it as '0' (true) or '1' (false), and returns the result to the bash variable $?
  $?	A variable used to find the return value as the exit status of the last executed command
  -eq	equals
  0	Value result is true
  ||	Logical "OR" is a Boolean operator. It can execute commands or shell functions based on the exit status of another command
  exit	Exits the shell with a status of N. If N is unspecified, it uses the exit code of the last executed command
  1	Value result is false and used here as an argument to the exit command to use as an exit code
  "you should have sudo privilege to run this script"	If the exit code is false, print this message to the terminal

  Test the last variable's exit code and see if it equals '0'. If not, exit with an error and print a given message to the terminal.

  Ref: https://linuxhint.com/bash-test-command/, http://tldp.org/LDP/abs/html/exit-status.html#EXSREF, https://bash.cyberciti.biz/guide/Logical_OR, https://linuxize.com/post/bash-exit/

• echo installing the must-have pre-requisites command:

  Command elements	Explanation
  echo	Builtin command used to print information or messages to the terminal
  installing the must-have pre-requisites	Message to print to the terminal

  Tell the user that it is going to install some pre-requisite packages before installing the actual program.

  Ref: https://linuxhint.com/bash_echo/

• while read -r p ; command:

  Command elements	Explanation
  while	Create a while-loop, i.e. perform a given set of commands ad infinitum as long as the given condition evaluates to true
  read	Read a line from the standard input and store it in a variable
  -r	Option passed to read command that avoids the backslash escapes from being interpreted
  p	Arbitrary variable for read to store captured input. Here it represents each package to be installed
  ;	Control operator AND. Proceed to the next command and execute it regardless of the exit status of the previous command (execute even if the previous command fails)

  Read a given file line by line forever or until receiving a value of "false," then continue onto the proceeding command.

  Ref: https://linuxize.com/post/bash-while-loop/, http://linuxcommand.org/lc3_man_pages/readh.html, https://linuxhint.com/while_read_line_bash/, https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_09_04_09

• do sudo apt-get install -y $p ; command:

  Command elements	Explanation
  do	Reserved word used to delimit the sequence of commands which follow. i.e., start
  apt-get	Tool used by the Debian APT (Advanced Package Tool) package manager
  install	A command used to install packages
  -y	Long-form is --yes. assume "yes" on all query prompts
  $p	Used to call the arbitrary variable p from read and use it as standard input

  Install the list of packages as a superuser without prompting for confirmation to install.

  Ref: https://itsfoss.com/apt-get-linux-guide/

• done < <(cat << "EOF" <list of packages> EOF) command:

  Command elements	Explanation
  done	Reserved word used to delimit the sequence of commands which precede. i.e., stop
  <	Redirection to the standard input
  cat	Concatenate. used for viewing, creating, and appending files
  <<	Redirection that reads input from the current source until encountering a delimiter and then using those lines as the standard input for a command
  EOF	End of File delimiter
  cat << EOF-EOF	This will read, then print everything enclosed within the EOF block
  <(list)	Obtain the output of the list; parentheses indicate that the list will execute in a subshell environment

  Read the list of packages and gather them as standard input. Redirect it to the read command, which captures it as the p variable, and then sends it to the $p variable, which allows it to get executed by the install command, and when it reaches the EOF delimiter, redirect the output to done effectively ending the while read loop.

  Ref: https://linuxhint.com/cat-command-bash/, https://linuxhint.com/what-is-cat-eof-bash-script/

The following four echo messages are self-explanatory:

• echo installing the nice-to-have pre-requisites
• echo you have 5 seconds to proceed ...
• echo or
• echo hit Ctrl+C to quit

however, the next one is not.

• echo -e "\n" command:

  Command elements	Explanation
  -e	Enable the function of backslash characters
  \n	Backslash escaped sequence for new line

  This command creates a newline.

• sleep 6 command:

  Command elements	Explanation
  sleep	Delay the execution of a bash script, typically for N seconds, unless using an option to indicate longer lengths of time

  Delay the execution of the following command for 6 seconds.

  Ref: https://linuxhandbook.com/bash-sleep/

• sudo apt-get install -y tig command:

  Install the tig package with the Debian apt-get tool while running the installation as a superuser, and do not prompt for confirmation.

General references:

• https://www.computerhope.com/unix/ubash.htm
• https://man7.org/linux/man-pages/man1/bash.1.html

I would opt for the following script: vim install

#!/bin/bash
apt-get update  # To get the latest package lists
apt-get install $1 -y

Then I should make the above script executable chmod +x install. Then to use it, I could type: ./install <package_name>. Example: ./install clang