get_file_chmod

#!/bin/bash
#
# @author Zeus Intuivo <zeus@intuivo.com>
#


# Bash: Detect pipe/file input in a shell script
# REF: https://gist.github.com/davejamesmiller/1966557

# How to detect whether input is from keyboard, a file, or another process.
# Useful for writing a script that can read from standard input, or prompt the
# user for input if there is none.

# Source: http://www.linuxquestions.org/questions/linux-software-2/bash-scripting-pipe-input-to-script-vs.-1-570945/
PIPED="";
COLORED="";
COUNTER=0;
# ag -i filefoo /bar/
# ag [FILE-TYPE] [OPTIONS] PATTERN [PATH]
# ack [OPTION]... PATTERN [FILES OR DIRECTORIES]
# sift [OPTIONS] PATTERN [FILE|PATH|tcp://HOST:PORT]...
#  sift [OPTIONS] [-e PATTERN | -f FILE] [FILE|PATH|tcp://HOST:PORT]...
#  sift [OPTIONS] --targets [FILE|PATH]...
#      grep [-abcdDEFGHhIiJLlmnOopqRSsUVvwxZ] [-A num] [-B num] [-C[num]] [-e pattern] [-f file]
#          [--binary-files=value] [--color[=when]] [--colour[=when]] [--context[=num]]
#          [--label] [--line-buffered] [--null] [pattern] [file ...]
# In Bash you can also use test -t to check for a terminal:

if [ -t 0 ]; then
    # Terminal input (keyboard) - interactive
    PIPED=""
else
    # File or pipe input - non-interactive
    PIPED="YES"
    # REF: http://stackoverflow.com/questions/2746553/bash-script-read-values-from-stdin-pipe
    # read PIPED #TOOD Works on mac osx, pending to test in linux and windows
    PIPED=''
    # REF: https://stackoverflow.com/questions/7314044/use-bash-to-read-line-by-line-and-keep-space
    # REF: http://www.unix.com/shell-programming-and-scripting/58611-resetting-ifs-variable.html
    OLDIFS=$IFS            # resetting IFS variable
    IFS=''                 # to read line by line and keep space
    IFS= read -r ONEPIPE   # to avoid interpretation of backslashes.
    PIPED="${ONEPIPE}"
        [ ! -z "$PIPED" ] && COUNTER=$((COUNTER+1))

    while read ONEPIPE
    do

         PIPED="${PIPED}
${ONEPIPE}"
         COUNTER=$((COUNTER+1))
    done
        if [ $COUNTER -eq 0 ]; then
          IFS=$OLDIFS
          exit
        fi

    #action="${ONEPIPE/ /⃝}"  # replace value inside string substitution expresion bash
    # TEST: echo "COUNTER: ${COUNTER}";echo "PIDED: ${PIPED}"; exit 0;
    IFS=$OLDIFS
fi
# Piped Input
#if [ ! -z "$PIPED" ]
# then
# echo "this is pipe..die "
# exit 0;
#fi
# NOT Piped Input
#if [ -z "$PIPED" ]
# then
# echo "this NOT pipe..die "
# exit 0;
#fi
#echo "PIPED:$PIPED";
#exit;

# ALTERNATIVE:
#if readlink /proc/$$/fd/0 | grep -q "^pipe:"; then
    # Pipe input (echo abc | myscript)
#    PIPED="YES"
#elif file $( readlink /proc/$$/fd/0 ) | grep -q "character special"; then
    # Terminal input (keyboard)
#    PIPED=""
#else
    # File input (myscript < file.txt)
#    PIPED=""

#fi


# CURRENT SCRIPT EXECUTING
THISSCRIPTNAME=`basename "$0"`


# PIPED ? - END

# ARGUMENTS ? - Start

# check to see if I used a message, then it will behave as a put
# bash shell script check input argument
FILENAME=""
VERBOSE=""
# Yes argument, not piped
if [ ! -z "$1" ] && [ -z "$PIPED" ]
  then
  {
    if [[ "$1" == "-v" ]] ;
      then
        VERBOSE="ON"
      else
        FILENAME="$1";
     fi
  }
fi
# Yes argument, yes piped
if [ ! -z "$1" ] && [ ! -z "$PIPED" ]
  then
  {
    if [[ "$1" == "-v" ]] ;
      then
        VERBOSE="ON"
    fi
    FILENAME="${PIPED}";
  }
fi

# Not argument, yes piped
if [ -z "$1" ] && [ ! -z "$PIPED" ]
  then
  {
    FILENAME="${PIPED}";
  }
fi
# Not argument, not Piped
if [ -z "$1" ] && [ -z "$PIPED" ]
  then
  {
    echo " "
    echo " 'Get the chmod numerical value for a file' REF: http://unix.stackexchange.com/questions/46915/get-the-chmod-numerical-value-for-a-file"
    echo "Missing 1st argument "
    echo " "
    echo "Sample Usage:    - expects one argument  *required"
    echo " "
    echo "    ${THISSCRIPTNAME}    filename [-v] for verbose"
    echo "    "
    echo "Pick one: "
    echo "    "
    ls
    exit 1;
  }
fi

# Yes argument, not piped
if [ ! -z "$2" ]
  then
  {
    if [[ "$2" == "-v" ]] ;
      then
        VERBOSE="ON"
     fi
  }
fi
# ARGUMENTS ? - END

# WHICH SYSTEM AND TAKE ACTION ? - Start
# check operation systems
(
  if [[ "$(uname)" == "Darwin" ]] ; then
    # Do something under Mac OS X platform
    while read -r ONE_FILENAME; do
      # if not empty
      PERMISIONS=""
      if [ ! -z "${ONE_FILENAME}" ] ; then
        PERMISIONS=$(stat -f "%OLp" "${ONE_FILENAME}")
      fi
      if [[ "${VERBOSE}" == "ON" ]] ;
        then
          {
            echo "${PERMISIONS} ${ONE_FILENAME}"
          }
        else
          {
            echo "${PERMISIONS}"
          }
      fi
    done <<< "${FILENAME}"

  elif [[ "$(expr substr $(uname -s) 1 5)" == "Linux" ]] ; then
    # Do something under GNU/Linux platform
    while read -r ONE_FILENAME; do
      # if not empty
      PERMISIONS=""
      if [ ! -z "${ONE_FILENAME}" ] ; then
        PERMISIONS=$(stat --format '%a' "${ONE_FILENAME}")
      fi
      if [[ "${VERBOSE}" == "ON" ]] ;
        then
          {
            echo "${PERMISIONS} ${ONE_FILENAME}"
          }
        else
          {
            echo "${PERMISIONS}"
          }
      fi
    done <<< "${FILENAME}"

  elif [[ "$(expr substr $(uname -s) 1 10)" == "MINGW32_NT" ]] || [[ "$(expr substr $(uname -s) 1 10)" == "MINGW64_NT" ]] ; then
    # Do something under Windows NT platform
     echo "Not learned yet. nothing"
    # nothing here
  fi
)
# WHICH SYSTEM AND TAKE ACTION ? - END