version bump

- `--uninstall` searches for all instances of `bak-old.sh` in PATH and
deletes them
- added the `is_command()` function

bak-old.sh

@@ -5,23 +5,37 @@
 #   - another Linux user tired of #
 #     type cp file file.bak       #
 ###################################
-version='0.1.0-beta'
+version='0.1.1-beta'
 
-### IFS precautions
+### IFS precautions	#
 OLDIFS="$IFS"
 unset IFS
+### error precautions
+set -e
+#####################
 
-### parse parameters
-# file names
-# `-d` dest dir
-# `-b | -o` mode: cloned file suffix
-# ` ` follow symlinks
-# ` ` lightweight copies
-
-debug(){
-    set -xev
+debug(){ ### function to call when $DEBUG is set
+    set -xv
 }
 
+# text formatting escape sequences
+txt_bold='\e[1m'
+txt_red='\e[31m'
+txt_green='\e[32m'
+txt_yellow='\e[33m'
+txt_0='\e[0m'
+
+is_command(){
+    if { command -v "$1"; } >/dev/null 2>/dev/null; then
+        return 0
+    else
+        return 1
+    fi
+}
+
+###############################################################################
+# f() FOR PRINTING PROMPTS
+#############################
 print_usage(){
     cat << HERE
 $(tput bold; tput setaf 3)${0##*/}$(tput sgr0)
@@ -31,190 +45,289 @@ $(tput bold)USAGE$(tput sgr0)
 
 $(tput bold)OPTIONS$(tput sgr0)
   Suffix for FILES -- only one can be used
-    -b	$(tput bold).bak$(tput sgr0) [default]
-    -o	$(tput bold).old$(tput sgr0)
+    -b	.bak [default]
+    -o	.old
 
   Destination for clones
     -d	save the clones in DESTINATION
-	[default] is the current directory
+          [default] is same as source file
 
   Lightweight copies
     -0  create if possible [default]
+          reuse data blocks unless modified
     -1  force regular copies
+          copy data blocks completely
 
   Recursive clone
     -r  clone a directory and its contents
+
+  Help and Version
+    -h  display this help menu
+    -v  print version
 HERE
 }
+
 print_version(){
     cat << HERE
 $(tput bold)${0##*/}: v${version}$(tput sgr0)
     by https://github.com/kevinnls
 HERE
 }
+
+print_err(){
+    tput setaf 1
+    case $1 in
+        bo)
+            echo "ERROR: modes backup and old cannot co-exist"
+            ;;
+        01)
+            echo "ERROR: lightweight copy modes cannot co-exist"
+            ;;
+        x)
+            echo "ERROR: unrecognised flags"
+            tput sgr0
+            print_usage
+            ;;
+        *)
+            echo "UNKNOWN ERROR"
+    esac
+    tput sgr0
+    exit 1
+}
+
+print_err_deps(){
+    tput setaf 1
+    cat <<- EOF
+	${0##*/} has the following unmet dependencies:${1/:/
+	  - }
+	EOF
+    tput sgr0
+    exit 1
+}
+
+copy_succ(){
+    echo " ✅ $(tput setaf 2; tput bold)${1}.${2:-bak}$(tput sgr0)"
+}
+copy_fail(){
+    echo " ❌ $(tput setaf 1; tput bold)${1}$(tput sgr0)"
+}
+copy_nofile(){
+    echo " ❌ $(tput setaf 1; tput bold)${1}$(tput sgr0) : file does not exist"
+}
+
+###############################################################################
+# f() FOR SETTING OPTIONS
+############################
 set_dest(){
     if [[ -n "$1" ]]  && ! realpath -e "$1" >/dev/null 2>&1 ;then
-	echo $1 does not exist
-	echo creating now...
-	mkdir -p $(realpath "$1")
-	[[ $? -ne 0 ]] && exit 1
+        echo $1 does not exist
+        echo creating now...
+        mkdir -p $(realpath "$1")
+        [[ $? -ne 0 ]] && exit 1
     fi
     dest=$(realpath "$1")
 }
 set_mode(){
     if [[ -z $mode ]]; then
-	mode=$1
+        mode=$1
     else
-	print_error 'bo'
+        print_err 'bo'
     fi
 }
 set_weight(){
     if [[ -z "$weight" ]]; then
-	weight="$1"
+        weight="$1"
     else
-	print_error '01'
+        print_err '01'
     fi
 }
 add_file(){
     files=("${files[@]}" "$1")
 }
 
+###############################################################################
+# f() FOR PARSING PARAMS AND OPTIONS
+#######################################
+
 in_combi(){
     [[ "$combi" =~ [:alnum:]*($1){1}[:alnum:]* ]]
 }
 un_combi(){
     combi=${combi/$1/}
 }
+
 parse_combined(){
 
     combi="${1/-/}"
 
     if in_combi 'b';then
-	set_mode bak
-	un_combi 'b'
+        set_mode bak
+        un_combi 'b'
     fi
     if in_combi 'o'; then
-	set_mode old
-	un_combi 'o'
+        set_mode old
+        un_combi 'o'
     fi
     if in_combi '0'; then
-	set_weight 'auto'
-	un_combi '0'
+        set_weight 'auto'
+        un_combi '0'
     fi
     if in_combi '1'; then
-	set_weight 'never'
-	un_combi '1'
+        set_weight 'never'
+        un_combi '1'
     fi
 
     [[ "$combi" =~ [:alnum:]*(d){1} ]] && set_dest $2 && ret=2
+        # setting return value to 2 to shift 2 in caller
+        # in case of -d <dest>
 
     if [[ -z "$combi" ]]; then
-	return ${ret:-1}
+        return ${ret:-1}
     else
-	print_error 'x'
-	exit 1
+        print_err 'x'
+        exit 1
     fi
 }
 
-print_error(){
-    tput setaf 1
-    case $1 in
-	bo)
-	    echo "ERROR: modes backup and old cannot co-exist"
-	    ;;
-	01)
-	    echo "ERROR: lightweight copy modes cannot co-exist"
-	    ;;
-	x)
-	    echo "ERROR: unrecognised flags"
-	    tput sgr0
-	    print_usage
-	    ;;
-	*)
-	    echo "UNKNOWN ERROR"
-    esac
-    tput sgr0
-    exit 1
-}
-copy_succ(){
-    echo " ✅ $(tput setaf 2; tput bold)$file.${mode:-bak}$(tput sgr0)"
-}
-copy_fail(){
-    echo " ❌ $(tput setaf 1; tput bold)$file$(tput sgr0)"
-}
-copy_nofile(){
-    echo " ❌ $(tput setaf 1; tput bold)$file$(tput sgr0) : file does not exist"
-}
-
-### enable debugging ###
+### enable debugging if ###
 ${DEBUG+debug}       ###
-### if $DEBUG is set ###
+### $DEBUG is set ###
 
 ###############################################################################
 # SANITISING PARAMS AND OPTIONS
-################################
+##################################
+if [[ "$1" == "--uninstall" ]]; then
+    install_locs=($(which -a bak-old.sh || echo ''))
+    echo "uninstalling script..."
+    echo
+    if [[ ${#install_locs[@]} -lt 1 ]]; then
+        echo -e "${txt_yellow}bak-old.sh installation not found in PATH${txt_0}"
+        exit 0
+    else
+        fail_count=0
+        set +e
+        for instance in "${install_locs[@]}"; do
+            rm -f $instance 2>/dev/null
+            if [[ $? -eq 0 ]]; then
+                echo -e "${txt_green}$instance deleted!${txt_0}"
+            else
+                fail_count=$(( fail_count + 1 ))
+                echo -e "${txt_red}$instance not deleted:${txt_0} try with sudo or as root"
+            fi
+        done
+        set -e
+        echo -e "${txt_bold}=========="
+        if [[ fail_count -eq 0 ]]; then
+            echo -e "${txt_green} bak-old.sh has been completely removed${txt_0}"
+            exit 0
+        else
+            echo -e "${txt_red} bak-old.sh not completely removed${txt_0}"
+            exit 1
+        fi
+    fi
+fi
+
+if [[ "$1" == "--up" ]]; then
+    if is_command curl; then
+        downloader='curl -fsSL'
+    elif is_command wget; then
+        downloader='wget -qO-'
+    else
+        echo -e "${txt_red}${txt_bold}ERR: wget or curl required for upgrading bak-old.sh${txt_0}"
+    fi
+    latest_version="$(${downloader} 'https://api.github.com/repos/kevinnls/bak-old/releases/latest' | awk -F \" '/tag_name/ {print $(NF-1)}')"
+    download_url="https://github.com/kevinnls/bak-old/releases/download/${latest_version}/install.sh"
+
+    ${downloader} ${download_url} | bash
+    exit 0
+fi
+
+if [[ $# -eq 0 ]]; then
+    print_usage
+fi
+
 while [[ $# -gt 0 ]]; do
     case $1 in
-	'-h' )
-	    print_usage
-	    exit 0
-	    ;;
-	'-v' )
-	    print_version
-	    exit 0
-	    ;;
-	'-r' )
-	    recurse='-r' #set_recurse
-	    shift 1
-	    ;;
-	'-d' )
-	    set_dest "$2"
-	    shift 2
-	    ;;
-	'-b' )
-	    set_mode 'bak'
-	    shift 1
-	    ;;
-	'-o' )
-	    set_mode 'old'
-	    shift 1
-	    ;;
-	'-0' )
-	    set_weight 'auto'
-	    shift 1
-	    ;;
-	'-1')
-	    set_weight 'never'
-	    shift 1
-	    ;;
-	-* )
-	    parse_combined "$1" "$2"
-	    shift $?
-	    ;;
-	* )
-	    add_file "$1"
-	    shift 1
-	    ;;
+    '-h' )
+        print_usage
+        exit 0
+        ;;
+    '-v' )
+        print_version
+        exit 0
+        ;;
+    '-r' )
+        recurse='-r' #set_recurse
+        shift 1
+        ;;
+    '-d' )
+        set_dest "$2"
+        shift 2
+        ;;
+    '-b' )
+        set_mode 'bak'
+        shift 1
+        ;;
+    '-o' )
+        set_mode 'old'
+        shift 1
+        ;;
+    '-0' )
+        set_weight 'auto'
+        shift 1
+        ;;
+    '-1')
+        set_weight 'never'
+        shift 1
+        ;;
+    -* )
+        parse_combined "$1" "$2"
+        shift $?
+        ;;
+    * )
+        add_file "$1"
+        shift 1
+        ;;
     esac
 done
 
+###############################################################################
+# CHECKING DEPS
+##################
+deps=(realpath)
 
-################################################################################
-# THE ACTUAL COPYING CODE
-##########################
-for file in "${files[@]}"; do
-    if realpath -e "$file" >/dev/null 2>&1 ;then
-	src_filepath="$(realpath "$file")"
-	dst_filepath="${dest:-${src_filepath%/*}}"
-	dst_filename="${src_filepath##*/}.${mode:-bak}"
-	cp_weight="--reflink=${weight:-auto}"
-	cp ${recurse} ${cp_weight} "$src_filepath" "$dst_filepath/$dst_filename"
-	[[ $? -eq 0 ]] && copy_succ || copy_fail
+for dep in $deps; do
+    if is_command "$dep" >/dev/null; then
+        continue
     else
-	copy_nofile
+        missing=":${dep}"
     fi
 done
 
-### reset IFS
-IFS="$OLDIFS"
+if [[ -n ${missing} ]]; then
+    print_err_deps $missing
+fi
 
+
+###############################################################################
+# THE ACTUAL COPYING CODE
+############################
+for file in "${files[@]}"; do
+    if realpath -e "$file" >/dev/null 2>&1 ;then
+
+        src_filepath="$(realpath "$file")"
+        dst_filepath="${dest:-${src_filepath%/*}}"
+        dst_filename="${src_filepath##*/}.${mode:-bak}"
+        cp_weight="--reflink=${weight:-auto}"
+
+        cp ${recurse} ${cp_weight} "$src_filepath" "$dst_filepath/$dst_filename"
+        [[ $? -eq 0 ]] && copy_succ $file $mode || copy_fail $file
+
+    else
+        copy_nofile $file
+    fi
+done
+
+### reset IFS###
+IFS="$OLDIFS"  #
+################

install.sh

@@ -0,0 +1,171 @@
+#!/bin/bash
+
+###################################
+# install script for bak-old.sh   #
+# authored by github.com/kevinnls #
+#   - another Linux user tired of #
+#     type cp file file.bak       #
+###################################
+
+set -e
+
+VERSION='v0.1.0-beta'
+work_dir=/tmp/bak-old_installation/
+tmp_file_path="$work_dir/bak-old.sh"
+download_url="https://github.com/kevinnls/bak-old/releases/download/${VERSION}/bak-old.sh"
+
+# list of known downloaders and options for download
+declare -A dlers
+dlers[curl]="curl -fsSLRo $tmp_file_path"
+dlers[wget]="wget -qO $tmp_file_path"
+# list of possible destinations for root user
+r_dstdirs=('/usr/local/bin' 
+			'/usr/bin' 
+			'/bin')
+# list of possible destinations for normal user
+u_dstdirs=("$HOME/.local/bin"
+			"$HOME/bin")
+
+declare downloader
+declare dest_dir
+
+debug(){ ### function to call when $DEBUG is set
+    set -xv
+}
+
+is_command(){ ### function to check if a command exists
+	{ command -v $1;} >/dev/null && return 0 || return 1
+}
+
+# text formatting escape sequences
+txt_bold='\e[1m'
+txt_red='\e[31m'
+txt_green='\e[32m'
+txt_yellow='\e[33m'
+txt_0='\e[0m'
+
+err_no_downloader(){
+	echo -e "$(cat <<- EOM
+	${txt_bold}${txt_red}ERR: missing dependencies${txt_0}
+
+	required by this installation script:
+	    - wget OR curl
+	install either application using your package manager and try again
+
+	alternatively, you can manually download the file from
+	    $download_url
+	to a directory in your PATH
+
+	EOM
+	)"
+	exit 1
+}
+err_no_dest_in_path(){
+	echo -e "$(cat <<-EOM
+	${txt_bold}${txt_red}ERR: no preconfigured destinations are in your PATH${txt_0}
+	check your PATH variable configuration
+	or specify the destination with -d
+
+	EOM
+	)"
+	exit 1
+}
+err_no_home_dir(){
+	echo -e "$(cat <<- EOM
+	${txt_bold}${txt_red}ERR: $(whoami) does not have a valid home directory${txt_0}
+
+	EOM
+	)"
+	exit 1
+}
+err_unknown(){
+	echo -e "$(cat <<-EOM
+	${txt_bold}${txt_red}ERR: some unhandled error has occurred${txt_0}
+	
+	EOM
+	)"
+	exit 1
+}
+install_success(){
+	echo -e "$(cat <<-EOM
+	${txt_bold}${txt_green}SUCCESS: bak-old.sh has been installed successfully${txt_0}
+	EOM
+	)"
+	bak-old.sh -h
+	exit 0
+}
+install_failure(){
+	echo -e "$(cat <<-EOM
+	${txt_bold}${txt_green}FAILUR: failed to install bak-old.sh :(${txt_0}
+	EOM
+	)"
+	exit 127
+}
+
+find_dler(){
+	for dler in ${!dlers[@]}; do
+		is_command $dler && downloader="${dlers[$dler]}"
+		[[ -n "$downloader" ]] && return
+	done
+
+	[[ -z "$downloader" ]] && err_no_downloader
+}
+
+find_dest_dir(){
+	local user_id=$(id -u)
+	local dirlist
+	if [[ user_id -eq 0 ]]; then
+		dirlist=(${r_dstdirs[@]})
+	elif [[ -d "$HOME" ]]; then
+		dirlist=(${u_dstdirs[@]})
+	elif [[ ! -d "$HOME" ]]; then
+		err_no_home_dir
+	else
+		err_unknown
+	fi
+			
+	for dir in ${dirlist[@]}; do
+		if [[ "$PATH" =~ /*:${dir}* ]] || [[ "$PATH" =~ /*${dir}:* ]]; then
+			dest_dir="$dir"
+		fi
+		[[ -n "$dest_dir" ]] && return
+	done
+
+	[[ -z "$dest_dir" ]] && err_no_dest_in_path
+}
+
+download(){
+	$downloader $download_url
+}
+
+setup() {
+	# setup
+	# create temp dir for installation work
+	mkdir -p "$work_dir"
+	cd "$work_dir"
+}
+
+cleanup(){
+	# cleanup
+	cd "$HOME"
+	rm -rf "$work_dir"
+	exit ${1-0}
+}
+
+trap "cleanup 1" SIGHUP SIGINT SIGTERM ERR
+
+install(){
+	setup
+	find_dler
+	find_dest_dir
+	download
+	chmod 755 "$tmp_file_path"
+	mv "$tmp_file_path" "${dest_dir}/"
+	is_command bak-old.sh && install_success || install_failure
+}
+
+### enable debugging if ###
+${DEBUG+debug}       ###
+### $DEBUG is set ###
+
+install