program_list

Have you ever wondered what all that stuff in /usr/bin does? Of course you have! Well, you could perform a whatis on every file in the directory (which can number a thousand or more on a typical system), or you could run the script below.

program_list is a program that creates an annotated list of programs in a directory (it defaults to /usr/bin) showing the description of each program. What's more, it also lists the name of the package the program belongs to; another helpful clue for determining what a program does.

The program sends its output to standard output in one of 3 different formats; plain text (the default), tab-separated values (great for post-processing the listing with other tools or loading it into a spreadsheet), and Markdown format (with pandoc extensions) for direct conversion into HTML and other formats.

program_list should work on any rpm (Red Hat, CentOS, Fedora, etc.) or deb (Debian, Ubuntu, etc.) based system. Note however, that due to the slow speed of package look up on most systems, program_list can take a long time to run (up to a half hour or more) depending the speed of your system and number of files involved.

In addition to the default directory /usr/bin, it's also good with /bin, /sbin, and /usr/sbin.

Examples

me@linuxbox ~ $ program_list > program_list.txt

Create a plain text listing of /usr/bin and store it in a file named program_list.txt.

me@linuxbox ~ $ program_list -t /usr/sbin > program_list_usr_sbin.tsv

Create a tab-separated value listing of /usr/sbin and store it in a file named program_list_usr_sbin.tsv.

Listing

#!/bin/bash
# ---------------------------------------------------------------------------
# program_list - Produce an annotated listing of programs

# Copyright 2014, William Shotts <bshotts@users.sourceforge.net>
  
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License at <http://www.gnu.org/licenses/> for
# more details.

# This program creates an annotated list of the programs in /usr/bin
# (or user-specified directory) including the filename, the package
# from which it was installed and a brief description taken from the
# program's man page, if available. The format of the listing can be
# plain text (the default), tab-separated values (useful for importing
# the listing into other programs), or Markdown format (with pandoc
# table extensions).

# Usage:  program_list [-h|--help]
#         program_list [[-m|--markdown]|[-t|--tabs]] [directory]

# Revision history:
# 2014-01-27 Strengthened against ugly file names (ver. 1.1)
# 2014-01-17 Created by new_script ver. 3.1
# ---------------------------------------------------------------------------

PROGNAME=${0##*/}
VERSION="1.1"

clean_up() { # Perform pre-exit housekeeping
  return
}

error_exit() { # Handle fatal errors
  echo -e "${PROGNAME}: ${1:-"Unknown Error"}" >&2
  clean_up
  exit 1
}

graceful_exit() {
  clean_up
  exit
}

signal_exit() { # Handle trapped signals
  case $1 in
    INT)
      error_exit "Program interrupted by user" ;;
    TERM)
      echo -e "\n$PROGNAME: Program terminated" >&2
      graceful_exit ;;
    *)
      error_exit "$PROGNAME: Terminating on unknown signal" ;;
  esac
}

usage() {
  echo -e "Usage: $PROGNAME [-h|--help]|[[-m|-t] [directory]]"
}

help_message() {
  cat <<- _EOF_
  $PROGNAME ver. $VERSION
  Produce an annotated listing of programs in a directory

  $(usage)

  Options:
  -h, --help      Display this help message and exit.
  -m, --markdown  Output Markdown formatted text (with pandoc
                  extensions).
  -t, --tabs      Output tab-separated values.
  
  directory is optional. Default is /usr/bin.

_EOF_
  return
}

set_mode() { # Set the output mode
  if [[ $mode == "empty" ]]; then
    mode=$1
  else
    error_exit "Only one mode (-m or -t) is allowed."
  fi
}

string() { # Write a string of character "char" repeated "width" times

  local -i width="$1"
  local char="$2"

  head -c "$width" < /dev/zero | tr '\0' "$char"
}

find_package() { # Search for package name based on distro

  local filename="$1" raw_package

  case $distro_style in
    debian)
      raw_package="$(dpkg-query -S "$filename" 2> /dev/null | tail -1)"
      echo "${raw_package%:*}"
      ;;
    redhat)
      rpm -qf "$filename" 2> /dev/null
      ;;
    *)
      error_exit "Unsupported distribution."
      ;;
  esac
}

# Trap signals
trap "signal_exit TERM" TERM HUP
trap "signal_exit INT"  INT

# Parse command-line
mode=empty
program_directory=/usr/bin
while [[ -n "$1" ]]; do
  case "$1" in
    -h | --help)
      help_message
      graceful_exit
      ;;
    -m | --markdown)
      set_mode markdown
      ;;
    -t | --tabs)
      set_mode tsv
      ;;
    -* | --*)
      usage
      error_exit "Unknown option $1"
      ;;
    *)
      program_directory="$1"
      break
      ;;
  esac
  shift
done

# Main logic

declare -a filenames packages descriptions
declare -i index=1 max_fn_len=0 fn_len=0 col1_width col2_width
distro_style="unknown"

# Determine type of packaging system
[[ -x /usr/bin/apt-get ]] && distro_style="debian"
[[ -x /bin/rpm || -x /usr/bin/rpm ]] && distro_style="redhat"

# Check if program_directory is valid
[[ -d "$program_directory" ]] || \
  error_exit "$program_directory cannot be read"
  
# Load arrays with filenames, packages, and descriptions
while IFS= read -r i; do
  filenames[index]="${i##*/}"
  fn_len=${#filenames[index]}
  # Determine longest filename for column width calculation
  [[ $fn_len -gt $max_fn_len ]] && max_fn_len=$fn_len

  packages[index]="$(find_package "$i")"

  # Get program description, strip off beginning and capitalize
  # first letter of first word.
  raw_description="$(whatis "${filenames[index]}" 2>/dev/null | head -1)"
  raw_description="${raw_description##*' - '}"
  descriptions[index]="${raw_description^*}"

  ((++index))
done < <(find "$program_directory" -mindepth 1 -maxdepth 1 -executable \
          -not -type d | sort -u)

# Insert Markdown header
if [[ $mode == "markdown" ]]; then
  markdown_header="Programs in $program_directory"
  echo -e "$markdown_header\n$(string ${#markdown_header} "=")\n\n"
  ((max_fn_len += 4)) # allow for extra characters added to filenames
fi

# Calculate column widths
col1_width=$((max_fn_len + 1))
col2_width=$((80 - col1_width))

# Insert Markdown table
if [[ $mode == "markdown" ]]; then
  echo "$(string $max_fn_len '-') $(string $col2_width '-')"
fi

for ((i=1; i<index; ++i)); do
  case $mode in
    empty)
      printf "%-${max_fn_len}s Package:%s\n" \
        "${filenames[i]}" \
        "${packages[i]}"
      # Fold description for second column
      echo "${descriptions[i]}" | \
        fold -s -w $col2_width | \
        pr -T -o $col1_width
      echo
      ;;
    tsv)
      printf "%s\t%s\t%s\n" \
        "${filenames[i]}" \
        "${packages[i]}" \
        "${descriptions[i]}" 
      ;;
    markdown)
      printf "%-${max_fn_len}s Package:%s\n\n" \
        "**${filenames[i]}**" \
        "${packages[i]}"
      echo "${descriptions[i]}" | \
        fold -s -w $col2_width | \
        pr -T -o $col1_width
      echo
      ;;
  esac
done

# Close Markdown table
[[ $mode == "markdown" ]] && echo -e "$(string 80 '-')\n"

graceful_exit

© 2000-2014, William E. Shotts, Jr. Verbatim copying and distribution of this entire article is permitted in any medium, provided this copyright notice is preserved.

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