mirror of
https://github.com/octoleo/hosts.git
synced 2024-11-22 04:45:11 +00:00
Rewrite as command-based program using bash boilerplate
This program contains the same functionality as previous iterations, with several changes: - move to command-based structure using the bash boilerplate template, - inlcude basic error handling, - revise variable naming and options for clarity, - prefer `printf` over `echo`, - misc other revisions.
This commit is contained in:
William Melody
parent
b88046cd4b
commit
42465bd461
703
hosts
703
hosts
@ -1,38 +1,679 @@
|
||||
#!/bin/bash
|
||||
# Idea and interface taken from https://github.com/macmade/host-manager
|
||||
#!/usr/bin/env bash
|
||||
#
|
||||
# __ __
|
||||
# / /_ ____ _____/ /______
|
||||
# / __ \/ __ \/ ___/ __/ ___/
|
||||
# / / / / /_/ (__ ) /_(__ )
|
||||
# /_/ /_/\____/____/\__/____/
|
||||
#
|
||||
# A program for managing host file entries.
|
||||
#
|
||||
# Based on Bash Boilerplate: https://github.com/alphabetum/bash-boilerplate
|
||||
#
|
||||
# Copyright (c) 2015 William Melody • hi@williammelody.com
|
||||
|
||||
path="/etc/hosts"
|
||||
addusage="Usage: `basename $0` --add host address"
|
||||
remusage="Usage: `basename $0` --remove host"
|
||||
listusage="Usage: `basename $0` --list [127.]"
|
||||
case "$1" in
|
||||
--add)
|
||||
if [ $# -eq 3 ]; then
|
||||
if [[ -n $(grep "^$3.*[^A-Za-z0-9\.]$2$" ${path}) ]]; then
|
||||
echo "Duplicate address/host combination, ${path} unchanged."
|
||||
else
|
||||
printf "$3\t$2\n" >> ${path}
|
||||
###############################################################################
|
||||
# Strict Mode
|
||||
###############################################################################
|
||||
|
||||
# Treat unset variables and parameters other than the special parameters ‘@’ or
|
||||
# ‘*’ as an error when performing parameter expansion. An 'unbound variable'
|
||||
# error message will be written to the standard error, and a non-interactive
|
||||
# shell will exit.
|
||||
#
|
||||
# This requires using parameter expansion to test for unset variables.
|
||||
#
|
||||
# http://www.gnu.org/software/bash/manual/bashref.html#Shell-Parameter-Expansion
|
||||
#
|
||||
# The two approaches that are probably the most appropriate are:
|
||||
#
|
||||
# ${parameter:-word}
|
||||
# If parameter is unset or null, the expansion of word is substituted.
|
||||
# Otherwise, the value of parameter is substituted. In other words, "word"
|
||||
# acts as a default value when the value of "$parameter" is blank. If "word"
|
||||
# is not present, then the default is blank (essentially an empty string).
|
||||
#
|
||||
# ${parameter:?word}
|
||||
# If parameter is null or unset, the expansion of word (or a message to that
|
||||
# effect if word is not present) is written to the standard error and the
|
||||
# shell, if it is not interactive, exits. Otherwise, the value of parameter
|
||||
# is substituted.
|
||||
#
|
||||
# Examples
|
||||
# ========
|
||||
#
|
||||
# Arrays:
|
||||
#
|
||||
# ${some_array[@]:-} # blank default value
|
||||
# ${some_array[*]:-} # blank default value
|
||||
# ${some_array[0]:-} # blank default value
|
||||
# ${some_array[0]:-default_value} # default value: the string 'default_value'
|
||||
#
|
||||
# Positional variables:
|
||||
#
|
||||
# ${1:-alternative} # default value: the string 'alternative'
|
||||
# ${2:-} # blank default value
|
||||
#
|
||||
# With an error message:
|
||||
#
|
||||
# ${1:?'error message'} # exit with 'error message' if variable is unbound
|
||||
#
|
||||
# Short form: set -u
|
||||
set -o nounset
|
||||
|
||||
# Exit immediately if a pipeline returns non-zero.
|
||||
#
|
||||
# NOTE: this has issues. When using read -rd '' with a heredoc, the exit
|
||||
# status is non-zero, even though there isn't an error, and this setting
|
||||
# then causes the script to exit. read -rd '' is synonymous to read -d $'\0',
|
||||
# which means read until it finds a NUL byte, but it reaches the EOF (end of
|
||||
# heredoc) without finding one and exits with a 1 status. Therefore, when
|
||||
# reading from heredocs with set -e, there are three potential solutions:
|
||||
#
|
||||
# Solution 1. set +e / set -e again:
|
||||
#
|
||||
# set +e
|
||||
# read -rd '' variable <<EOF
|
||||
# EOF
|
||||
# set -e
|
||||
#
|
||||
# Solution 2. <<EOF || true:
|
||||
#
|
||||
# read -rd '' variable <<EOF || true
|
||||
# EOF
|
||||
#
|
||||
# Solution 3. Don't use set -e or set -o errexit at all.
|
||||
#
|
||||
# More information:
|
||||
#
|
||||
# https://www.mail-archive.com/bug-bash@gnu.org/msg12170.html
|
||||
#
|
||||
# Short form: set -e
|
||||
set -o errexit
|
||||
|
||||
# Return value of a pipeline is the value of the last (rightmost) command to
|
||||
# exit with a non-zero status, or zero if all commands in the pipeline exit
|
||||
# successfully.
|
||||
set -o pipefail
|
||||
|
||||
# Set IFS to just newline and tab at the start
|
||||
#
|
||||
# http://www.dwheeler.com/essays/filenames-in-shell.html
|
||||
#
|
||||
# $DEFAULT_IFS and $SAFER_IFS
|
||||
#
|
||||
# $DEFAULT_IFS contains the default $IFS value in case it's needed, such as
|
||||
# when expanding an array and you want to separate elements by spaces.
|
||||
# $SAFER_IFS contains the preferred settings for the program, and setting it
|
||||
# separately makes it easier to switch between the two if needed.
|
||||
#
|
||||
# NOTE: also printing $DEFAULT_IFS to /dev/null to avoid shellcheck warnings
|
||||
# about the variable being unused.
|
||||
DEFAULT_IFS="$IFS"; printf "%s" "$DEFAULT_IFS" > /dev/null
|
||||
SAFER_IFS="$(printf '\n\t')"
|
||||
# Then set $IFS
|
||||
IFS="$SAFER_IFS"
|
||||
|
||||
###############################################################################
|
||||
# Globals
|
||||
###############################################################################
|
||||
|
||||
_VERSION="0.1.0-alpha"
|
||||
|
||||
###############################################################################
|
||||
# Debug
|
||||
###############################################################################
|
||||
|
||||
# _debug()
|
||||
#
|
||||
# A simple function for executing a specified command if the `_use_debug`
|
||||
# variable has been set. The command is expected to print a message and
|
||||
# should typically be either `echo`, `printf`, or `cat`.
|
||||
#
|
||||
# Usage:
|
||||
# _debug printf "Debug info. Variable: %s\n" "$0"
|
||||
_debug() {
|
||||
if [[ "${_use_debug:-"0"}" -eq 1 ]]; then
|
||||
# Prefix debug message with "bug (U+1F41B)"
|
||||
printf "🐛 "
|
||||
"$@"
|
||||
printf "――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――\n"
|
||||
fi
|
||||
}
|
||||
# debug()
|
||||
#
|
||||
# Print the specified message if the `_use_debug` variable has been set.
|
||||
#
|
||||
# This is a shortcut for the _debug() function that simply echos the message.
|
||||
#
|
||||
# Usage:
|
||||
# debug "Debug info. Variable: $0"
|
||||
debug() {
|
||||
_debug echo "$@"
|
||||
}
|
||||
|
||||
###############################################################################
|
||||
# Die
|
||||
###############################################################################
|
||||
|
||||
# _die()
|
||||
#
|
||||
# A simple function for exiting with an error after executing the specified
|
||||
# command. The command is expected to print a message and should typically
|
||||
# be either `echo`, `printf`, or `cat`.
|
||||
#
|
||||
# Usage:
|
||||
# _die printf "Error message. Variable: %s\n" "$0"
|
||||
_die() {
|
||||
# Prefix die message with "cross mark (U+274C)", often displayed as a red x.
|
||||
printf "❌ "
|
||||
"$@" 1>&2
|
||||
exit 1
|
||||
}
|
||||
# die()
|
||||
#
|
||||
# Exit with an error and print the specified message.
|
||||
#
|
||||
# This is a shortcut for the _die() function that simply echos the message.
|
||||
#
|
||||
# Usage:
|
||||
# die "Error message. Variable: $0"
|
||||
die() {
|
||||
_die echo "$@"
|
||||
}
|
||||
|
||||
###############################################################################
|
||||
# Options
|
||||
###############################################################################
|
||||
|
||||
# Get raw options for any commands that expect them.
|
||||
raw_options="$*"
|
||||
|
||||
# Steps:
|
||||
#
|
||||
# 1. set expected short options in `optstring` at beginning of the "Normalize
|
||||
# Options" section,
|
||||
# 2. parse options in while loop in the "Parse Options" section.
|
||||
|
||||
# Normalize Options ###########################################################
|
||||
|
||||
# Source:
|
||||
# https://github.com/e36freak/templates/blob/master/options
|
||||
|
||||
# The first loop, even though it uses 'optstring', will NOT check if an
|
||||
# option that takes a required argument has the argument provided. That must
|
||||
# be done within the second loop and case statement, yourself. Its purpose
|
||||
# is solely to determine that -oARG is split into -o ARG, and not -o -A -R -G.
|
||||
|
||||
# Set short options -----------------------------------------------------------
|
||||
|
||||
# option string, for short options.
|
||||
#
|
||||
# Very much like getopts, expected short options should be appended to the
|
||||
# string here. Any option followed by a ':' takes a required argument.
|
||||
#
|
||||
# In this example, `-x` and `-h` are regular short options, while `o` is
|
||||
# assumed to have an argument and will be split if joined with the string,
|
||||
# meaning `-oARG` would be split to `-o ARG`.
|
||||
optstring=h
|
||||
|
||||
# Normalize -------------------------------------------------------------------
|
||||
|
||||
# iterate over options, breaking -ab into -a -b and --foo=bar into --foo bar
|
||||
# also turns -- into --endopts to avoid issues with things like '-o-', the '-'
|
||||
# should not indicate the end of options, but be an invalid option (or the
|
||||
# argument to the option, such as wget -qO-)
|
||||
unset options
|
||||
# while the number of arguments is greater than 0
|
||||
while (($#)); do
|
||||
case $1 in
|
||||
# if option is of type -ab
|
||||
-[!-]?*)
|
||||
# loop over each character starting with the second
|
||||
for ((i=1; i<${#1}; i++)); do
|
||||
# extract 1 character from position 'i'
|
||||
c=${1:i:1}
|
||||
# add current char to options
|
||||
options+=("-$c")
|
||||
|
||||
# if option takes a required argument, and it's not the last char
|
||||
# make the rest of the string its argument
|
||||
if [[ $optstring = *"$c:"* && ${1:i+1} ]]; then
|
||||
options+=("${1:i+1}")
|
||||
break
|
||||
fi
|
||||
done
|
||||
;;
|
||||
# if option is of type --foo=bar, split on first '='
|
||||
--?*=*) options+=("${1%%=*}" "${1#*=}");;
|
||||
# end of options, stop breaking them up
|
||||
--)
|
||||
options+=(--endopts)
|
||||
shift
|
||||
options+=("$@")
|
||||
break
|
||||
;;
|
||||
# otherwise, nothing special
|
||||
*) options+=("$1");;
|
||||
esac
|
||||
|
||||
shift
|
||||
done
|
||||
# set new positional parameters to altered options. Set default to blank.
|
||||
set -- "${options[@]:-}"
|
||||
unset options
|
||||
|
||||
# Parse Options ###############################################################
|
||||
|
||||
# Initialize command_argv array
|
||||
#
|
||||
# This array contains all of the arguments that get passed along to each
|
||||
# command. This is essentially the same as the program arguments, minus those
|
||||
# that have been filtered out in the program option parsing loop. This array
|
||||
# is initialized with $0, which is the program's name.
|
||||
command_argv=("$0")
|
||||
# Initialize $cmd and $_use_debug, which can continue to be blank depending on
|
||||
# what the program needs.
|
||||
cmd=""
|
||||
_use_debug=0
|
||||
|
||||
while [ $# -gt 0 ]; do
|
||||
opt="$1"
|
||||
shift
|
||||
case "$opt" in
|
||||
-h|--help)
|
||||
cmd="help"
|
||||
;;
|
||||
--version)
|
||||
cmd="version"
|
||||
;;
|
||||
--debug)
|
||||
_use_debug=1
|
||||
;;
|
||||
*)
|
||||
# The first non-option argument is assumed to be the command name.
|
||||
# All subsequent arguments are added to $command_arguments.
|
||||
if [[ -n $cmd ]]; then
|
||||
command_argv+=("$opt")
|
||||
else
|
||||
cmd="$opt"
|
||||
fi
|
||||
;;
|
||||
esac
|
||||
done
|
||||
|
||||
# Set $command_parameters to $command_argv, minus the initial element, $0. This
|
||||
# provides an array that is equivalent to $* and $@ within each command
|
||||
# function, though the array is zero-indexed, which could lead to confusion.
|
||||
command_parameters=("${command_argv[@]:1}")
|
||||
|
||||
_debug printf "\$cmd: %s\n" "$cmd"
|
||||
_debug printf "\$raw_options (one per line):\n%s\n" "$raw_options"
|
||||
_debug printf "\$command_argv: %s\n" "${command_argv[*]}"
|
||||
_debug printf "\$command_parameters: %s\n" "${command_parameters[*]:-}"
|
||||
|
||||
###############################################################################
|
||||
# Environment
|
||||
###############################################################################
|
||||
|
||||
# $_me
|
||||
#
|
||||
# Set to the program's basename.
|
||||
_me=$(basename "$0")
|
||||
|
||||
_debug printf "\$_me: %s\n" "$_me"
|
||||
|
||||
###############################################################################
|
||||
# Load Commands
|
||||
###############################################################################
|
||||
|
||||
# Initialize defined_commands array.
|
||||
defined_commands=()
|
||||
|
||||
# _load_commands()
|
||||
#
|
||||
# Loads all of the commands sourced in the environment.
|
||||
#
|
||||
# Usage:
|
||||
# _load_commands
|
||||
_load_commands() {
|
||||
|
||||
_debug printf "_load_commands(): entering...\n"
|
||||
_debug printf "_load_commands() declare -F:\n%s\n" "$(declare -F)"
|
||||
|
||||
# declare is a bash built-in shell function that, when called with the '-F'
|
||||
# option, displays all of the functions with the format
|
||||
# `declare -f function_name`. These are then assigned as elements in the
|
||||
# $function_list array.
|
||||
local function_list=($(declare -F))
|
||||
|
||||
for c in "${function_list[@]}"
|
||||
do
|
||||
# Each element has the format `declare -f function_name`, so set the name
|
||||
# to only the 'function_name' part of the string.
|
||||
local function_name=$(printf "%s" "$c" | awk '{ print $3 }')
|
||||
|
||||
_debug printf "_load_commands() \$function_name: %s\n" "$function_name"
|
||||
|
||||
# Add the function name to the $defined_commands array unless it starts
|
||||
# with an underscore or is one of the desc(), debug(), or die() functions,
|
||||
# since these are treated as having 'private' visibility.
|
||||
if ! ( [[ "$function_name" =~ ^_(.*) ]] || \
|
||||
[[ "$function_name" == "desc" ]] || \
|
||||
[[ "$function_name" == "debug" ]] || \
|
||||
[[ "$function_name" == "die" ]]
|
||||
); then
|
||||
defined_commands+=("$function_name")
|
||||
fi
|
||||
else
|
||||
echo $addusage;
|
||||
done
|
||||
|
||||
_debug printf \
|
||||
"commands() \$defined_commands:\n%s\n" \
|
||||
"${defined_commands[*]:-}"
|
||||
}
|
||||
|
||||
###############################################################################
|
||||
# Main
|
||||
###############################################################################
|
||||
|
||||
# _main()
|
||||
#
|
||||
# Usage:
|
||||
# _main
|
||||
#
|
||||
# The primary function for starting the program.
|
||||
#
|
||||
# NOTE: must be called at end of program after all commands have been defined.
|
||||
_main() {
|
||||
_debug printf "main(): entering...\n"
|
||||
_debug printf "main() \$cmd (upon entering): %s\n" "$cmd"
|
||||
|
||||
# If $cmd is blank, then set to help
|
||||
if [[ -z $cmd ]]; then
|
||||
cmd="help"
|
||||
fi
|
||||
;;
|
||||
--remove)
|
||||
if [ $# -eq 2 ]; then
|
||||
sed -i '' "s/^[^#].*[^A-Za-z0-9\.]$2$//g;/^$/d" ${path}
|
||||
|
||||
# Load all of the commands.
|
||||
_load_commands
|
||||
|
||||
# If the command is defined, run it, otherwise return an error.
|
||||
if ( _contains "$cmd" "${defined_commands[*]:-}" ); then
|
||||
# Pass all comment arguments to the program except for the first ($0).
|
||||
$cmd "${command_parameters[@]:-}"
|
||||
else
|
||||
echo $remusage;
|
||||
_die printf "Unknown command: %s\n" "$cmd"
|
||||
fi
|
||||
;;
|
||||
--list)
|
||||
if [ $# -eq 2 ]; then
|
||||
grep "^$2" ${path}
|
||||
}
|
||||
|
||||
###############################################################################
|
||||
# Utility Functions
|
||||
###############################################################################
|
||||
|
||||
# _function_exists()
|
||||
#
|
||||
# Takes a potential function name as an argument and returns whether a function
|
||||
# exists with that name.
|
||||
_function_exists() {
|
||||
[ "$(type -t "$1")" == 'function' ]
|
||||
}
|
||||
|
||||
# _contains()
|
||||
#
|
||||
# Takes an item and a list and determines whether the list contains the item.
|
||||
#
|
||||
# Usage:
|
||||
# _contains "$item" "${list[*]}"
|
||||
_contains() {
|
||||
local test_list=(${*:2})
|
||||
for _test_element in "${test_list[@]:-}"
|
||||
do
|
||||
_debug printf "_contains() \$_test_element: %s\n" "$_test_element"
|
||||
if [[ "$_test_element" == "$1" ]]; then
|
||||
_debug printf "_contains() match: %s\n" "$1"
|
||||
return 0
|
||||
fi
|
||||
done
|
||||
return 1
|
||||
}
|
||||
|
||||
# _command_argv_includes()
|
||||
#
|
||||
# Takes a possible command argument and determines whether it is included in
|
||||
# the command argument list.
|
||||
#
|
||||
# This is a shortcut for simple cases where a command wants to check for the
|
||||
# presence of options quickly without parsing the options again.
|
||||
#
|
||||
# Usage:
|
||||
# _command_argv_includes "an_argument"
|
||||
_command_argv_includes() {
|
||||
_contains "$1" "${command_argv[*]}"
|
||||
}
|
||||
|
||||
###############################################################################
|
||||
# desc
|
||||
###############################################################################
|
||||
|
||||
# desc()
|
||||
#
|
||||
# Usage:
|
||||
# desc command "description"
|
||||
#
|
||||
# Create a description for a specified command name. The command description
|
||||
# text can be passed as the second argument or as standard input.
|
||||
#
|
||||
# To make the description text available to other functions, desc() assigns the
|
||||
# text to a variable with the format $_desc_function_name
|
||||
#
|
||||
# NOTE:
|
||||
#
|
||||
# The `read` form of assignment is used for a balance of ease of
|
||||
# implementation and simplicity. There is an alternative assignment form
|
||||
# that could be used here:
|
||||
#
|
||||
# var="$(cat <<'EOM'
|
||||
# some message
|
||||
# EOM
|
||||
# )
|
||||
#
|
||||
# However, this form appears to require trailing space after backslases to
|
||||
# preserve newlines, which is unexpected. Using `read` simply requires
|
||||
# escaping backslashes, which is more common.
|
||||
desc() {
|
||||
set +e
|
||||
[[ -z $1 ]] && _die printf "desc: No command name specified.\n"
|
||||
if [[ -n ${2:-} ]]; then
|
||||
read -d '' "_desc_$1" <<EOM
|
||||
$2
|
||||
EOM
|
||||
_debug printf "desc() set with argument: _desc_%s\n" "$1"
|
||||
else
|
||||
cat ${path} | grep -v "^#"
|
||||
read -d '' "_desc_$1"
|
||||
_debug printf "desc() set with pipe: _desc_%s\n" "$1"
|
||||
fi
|
||||
;;
|
||||
*)
|
||||
echo $addusage;
|
||||
echo $remusage;
|
||||
echo $listusage;
|
||||
esac
|
||||
set -e
|
||||
}
|
||||
|
||||
# _print_desc()
|
||||
#
|
||||
# Usage:
|
||||
# _print_desc <command>
|
||||
#
|
||||
# Prints the description for a given command, provided the description has been
|
||||
# set using the desc() function.
|
||||
_print_desc() {
|
||||
local var="_desc_$1"
|
||||
if [[ -n ${!var:-} ]]; then
|
||||
printf "%s\n" "${!var}"
|
||||
else
|
||||
printf "No additional information for \`%s\`\n" "$1"
|
||||
fi
|
||||
}
|
||||
|
||||
###############################################################################
|
||||
# Default Commands
|
||||
###############################################################################
|
||||
|
||||
# Version #####################################################################
|
||||
|
||||
desc version <<EOM
|
||||
Usage:
|
||||
$_me ( version | --version )
|
||||
|
||||
Description:
|
||||
Display the current program version.
|
||||
|
||||
To save you the trouble, the current version is $_VERSION
|
||||
EOM
|
||||
version() {
|
||||
printf "%s\n" "$_VERSION"
|
||||
}
|
||||
|
||||
# Help ########################################################################
|
||||
|
||||
desc help <<EOM
|
||||
Usage:
|
||||
$_me help [<command>]
|
||||
|
||||
Description:
|
||||
Display help information for $_me or a specified command.
|
||||
EOM
|
||||
help() {
|
||||
if [[ ${#command_argv[@]} = 1 ]]; then
|
||||
cat <<EOM
|
||||
__ __
|
||||
/ /_ ____ _____/ /______
|
||||
/ __ \/ __ \/ ___/ __/ ___/
|
||||
/ / / / /_/ (__ ) /_(__ )
|
||||
/_/ /_/\____/____/\__/____/
|
||||
|
||||
A program for managing host file entries.
|
||||
|
||||
Version: $_VERSION
|
||||
|
||||
Usage:
|
||||
$_me command [--command-options] [<arguments>]
|
||||
$_me -h | --help
|
||||
$_me --version
|
||||
|
||||
Options:
|
||||
-h --help Display this help information.
|
||||
--version Display version information.
|
||||
|
||||
Help:
|
||||
$_me help [<command>]
|
||||
|
||||
$(commands)
|
||||
EOM
|
||||
else
|
||||
_print_desc "$1"
|
||||
fi
|
||||
}
|
||||
|
||||
# Command List ################################################################
|
||||
|
||||
desc commands <<EOM
|
||||
Usage:
|
||||
$_me commands [--raw]
|
||||
|
||||
Options:
|
||||
--raw Display the command list without formatting.
|
||||
|
||||
Description:
|
||||
Display the list of available commands.
|
||||
EOM
|
||||
commands() {
|
||||
if _command_argv_includes "--raw"; then
|
||||
printf "%s\n" "${defined_commands[@]}"
|
||||
else
|
||||
printf "Available commands:\n"
|
||||
printf " %s\n" "${defined_commands[@]}"
|
||||
fi
|
||||
}
|
||||
|
||||
###############################################################################
|
||||
# Commands
|
||||
# ========.....................................................................
|
||||
#
|
||||
# Example command group structure:
|
||||
#
|
||||
# desc example "" - Optional. A short description for the command.
|
||||
# example() { : } - The command called by the user.
|
||||
#
|
||||
#
|
||||
# desc example <<EOM
|
||||
# Usage:
|
||||
# $_me example
|
||||
#
|
||||
# Description:
|
||||
# Print "Hello, World!"
|
||||
#
|
||||
# For usage formatting conventions see:
|
||||
# - http://docopt.org/
|
||||
# - http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap12.html
|
||||
# EOM
|
||||
# example() {
|
||||
# printf "Hello, World!\n"
|
||||
# }
|
||||
#
|
||||
###############################################################################
|
||||
|
||||
# ------------------------------------------------------------------------- add
|
||||
|
||||
desc add <<EOM
|
||||
Usage: $_me add ip hostname
|
||||
EOM
|
||||
add() {
|
||||
local ip=${1:-}
|
||||
local hostname=${2:-}
|
||||
if [[ -z ${ip} ]]; then
|
||||
$_me help add
|
||||
exit 1
|
||||
elif [[ -z ${hostname} ]]; then
|
||||
printf "Please include a hostname\n"
|
||||
$_me help add
|
||||
exit 1
|
||||
elif grep "^${ip}.*[^A-Za-z0-9\.]${hostname}$" /etc/hosts ; then
|
||||
_die printf "Duplicate address/host combination, /etc/hosts unchanged.\n"
|
||||
else
|
||||
printf "%s\t%s\n" "${ip}" "${hostname}" >> /etc/hosts
|
||||
fi
|
||||
}
|
||||
|
||||
# ------------------------------------------------------------------------ list
|
||||
|
||||
desc list <<EOM
|
||||
Usage: $_me list [127.]
|
||||
EOM
|
||||
list() {
|
||||
if [[ -n "$1" ]]; then
|
||||
grep "^$1" /etc/hosts
|
||||
else
|
||||
# NOTE: use separate expressions since using a | for the or results in
|
||||
# inconsistent behavior.
|
||||
grep -v -e '^$' -e '^\s*\#' /etc/hosts
|
||||
fi
|
||||
}
|
||||
|
||||
# ---------------------------------------------------------------------- remove
|
||||
|
||||
desc remove <<EOM
|
||||
Usage: $_me remove host
|
||||
EOM
|
||||
remove() {
|
||||
local hostname=${1:-}
|
||||
if [[ -z $hostname ]]; then
|
||||
$_me help remove
|
||||
exit 1
|
||||
else
|
||||
sed -i "s/^[^#].*[^A-Za-z0-9\.]${hostname}$//g;/^$/d" /etc/hosts
|
||||
fi
|
||||
}
|
||||
|
||||
###############################################################################
|
||||
# Run Program
|
||||
###############################################################################
|
||||
|
||||
# Calling the _main function after everything has been defined.
|
||||
_main
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user