Translate Unix manual pages into text files

man2txt.sh

#! /bin/bash
#============================================================================#
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#          /     \\__  \  /    \  /  ____/\   __\  \/  /\   __\
#         |  Y Y  \/ __ \|   |  \/       \ |  |  >    <  |  |  
#         |__|_|  (____  /___|  /\_______ \|__| /__/\_ \ |__|  
#               \/     \/     \/         \/           \/       
#
#============================================================================#
#
# INFORMATION
#
#    man2txt - Translate Unix manual pages into text files
#
#    Created by h8rt3rmin8r on 20190126
#    Source: http://bit.ly/man2txt-sh
#
# USAGE
#
#    ./man2txt.sh <UNIX_COMMAND>
#    ./man2txt.sh <COMMAND_1> <COMMAND_2> ... <COMMAND_N>
#    ./man2txt.sh [OPTIONS]
#    ./man2txt.sh [OPTIONS] <COMMAND>
#    ./man2txt.sh [OPTIONS] <COMMAND_1> <COMMAND_2> ... <COMMAND_N>
#
# OPTIONS
#
#    ______________________________________________________________________
#    |               |                                                     |
#    |  -h,--help    |  Print the man2txt help text                        |
#    |  -l,--list    |  Output a list of completed manual text files       |
#    |  -t,--table   |  Output a table of completed manual text files      |
#    |  -c,--clean   |  Remove empty files from the "~/man" directory      |
#    |  -s,--silent  |  Run silently (requires <COMMAND>)                  |
#    |  --test       |  Print all core variables used in man2txt           |
#    |_______________|_____________________________________________________|
#
#============================================================================#
# VARIABLE DECLARATIONS

USER=$(cd; pwd | cut -c 7-)
HOME="/home/${USER}"
SELF="[man2txt]"
DT=$(date '+%Y%m%d')
DT_NOW="${DT}_$(date '+%H-%M-%S')"
VBX="/dev/stdout"
HOME_DIR="${HOME}/man"
LOGS_DIR="${HOME_DIR}/logs"
LOG_FILE="${LOGS_DIR}/${DT}.log"
LINE_X='======='
LINE_Y="${LINE_X}${LINE_X}${LINE_X}${LINE_X}"
LINE="${LINE_Y}${LINE_Y}"
LINE__X='-------'
LINE__Y="${LINE__X}${LINE__X}${LINE__X}${LINE__X}"
LINEA="${LINE__Y}${LINE__Y}"
ALL_INPUTS=()

#============================================================================#
# FUNCTION DECLARATIONS

function help_text() {
    # Output the script help text
    cat $0 | head -n 38 | tail -n +2 | sed 's/#/ /g'
    return
}

function manual_clean() {
    # Remove all manual text files that contain zero bytes of data
    echo "${SELF} Performing integrity checks on output files" &>${VBX}
    MAN_LIST=( $(ls ${HOME_DIR}) )
    for i in "${MAN_LIST[@]}";
    do
        if [[ -f "${HOME_DIR}/$i" && "$(cat ${HOME_DIR}/$i | wc -c)" == 0 ]];
        then
            rm "${HOME_DIR}/$i"
        fi
    done
    echo "${SELF} Done. Output files and logs are located at ~/man" &>${VBX}
    return
}

function manual_list() {
    # Output a list of completed manual text files
    MAN_LIST=( $(ls ${HOME_DIR}) )
    for i in ${MAN_LIST[@]};
    do
        if [[ -f "$i" ]];
        then
            echo "$i"
        fi
    done
    return
}

function manual_table() {
    # Output a table of completed manual text files
    MANUAL_ARRAY=( $(manual_list) )
    for i in "${MANUAL_ARRAY[@]}";
    do
        printf '%s\t%s\n' "$i@($(cat $i | wc -c))"
    done >> temp-data.txt
    column -t -s@ temp-data.txt
    rm temp-data.txt
    return
}

function run_man2txt() {
    # Execute the core manual conversion process
    echo "${SELF} Beginning manual conversion process" &>${VBX}
    for i in "${ALL_INPUTS[@]}";
    do
        man $i 2>>${LOG_FILE} | col -bx 1> "${HOME_DIR}/$i.m" 2>>"${LOG_FILE}"
    done
    echo "${SELF} Done. Output files and logs are located at ~/man" &>${VBX}
    return
}

function test_man2txt() {
    # Testing function for the man2txt script
    echo "${LINE}"
    echo "USER:          ${USER}"
    echo "DT:            ${DT}"
    echo "DT_NOW:        ${DT_NOW}"
    echo "VBX:           ${VBX}"
    echo "HOME:          ${HOME}"
    echo "HOME_DIR:      ${HOME_DIR}"
    echo "LOGS_DIR:      ${LOGS_DIR}"
    echo "LOG_FILE:      ${LOG_FILE}"
    echo "${LINEA}"
    echo "ALL_INPUTS:    ${ALL_INPUTS[@]}"
    echo "${LINE}"
    return
}

#============================================================================#
# INPUT FILTERING AND OPERATIONS EXECUTION

# Filter null inputs
if [[ "x$1" == "x" ]]; then help_text; exit 1; fi

# Intelligently assign the input data array
if [[ "$(echo $1 | cut -c 1)" == '-' ]];
then
    ALL_INPUTS=( $(echo "${@:2}") )
else
    ALL_INPUTS=( $(echo "$@") )
fi

# Filter out unique requests which don't require a full runtime
case "$1" in
    '-h'|'-help'|'--help') help_text; exit 0 ;;
    '-l'|'-list'|'--list') manual_list; exit 0 ;;
    '-t'|'-table'|'--table') manual_table; exit 0 ;;
    '-c'|'-clean'|'--clean') manual_clean; exit 0 ;;
    '-test'|'--test') test_man2txt; exit 0 ;;
    '-s'|'-silent'|'--silent') VBX="/dev/null" ;;
esac

# Create the required directories if they don't exist
mkdir -p "${HOME_DIR}" &>/dev/null
mkdir -p "${LOGS_DIR}" &>/dev/null

# Create the log file if it doesn't exist and log the current runtime
touch "${LOG_FILE}" &>/dev/null
echo "${SELF} [${DT_NOW}] ${LINE}" >> ${LOG_FILE}

# Execute the core script operations
#test_man2txt
run_man2txt
manual_clean

#============================================================================#