Batch change the mode bit (the permission of files and directories)

chmodbatch.sh

#!/bin/bash

# Batch change the mode bit (the permission of files and directories)
#
# USAGE:    script_name [path1] [path2]...
#           script_name
#
# Author:   Jongmin Kim (kdzlvaids@gmail.com)


#
# Settings
#

# Verbose mode
#
# Default value: 1
# Available values:
#   0   Disable
#   1   Enable
export verbose=1

# Scan the executable file
# Recognise the executable file, and use $modebit_exec instead of
# $modebit_file. This will slow down the processing speed.
#
# Default value: 1
# Available values:
#   0   Disable
#   1   Enable
export enable_execscan=1

# Mode bit for a directory
#
# Default value: $(expr 777 - $(umask))
export modebit_dir=$(expr 777 - $(umask))

# Mode bit for a file
#
# Default value: $(expr 666 - $(umask))
export modebit_file=$(expr 666 - $(umask))

# Mode bit for an executable file
#
# Default value: $(expr 777 - $(umask))
export modebit_exec=$(expr 777 - $(umask))


#
# Functions
#

# Functions for printing the string
echo_success()          { (     echo "'$1' to $2$3..."                              ) } # $1:path $2:mode $3:comment
echo_warn()             { (>&2  echo "Warning: '$1' is $2. Skipping..."             ) } # $1:path $2:type
echo_warn_not_found()   { (>&2  echo "Warning: File '$1' not found. Skipping..."    ) } # $1:path
echo_error_not_found()  { (>&2  echo "Error: File '$1' not found."                  ) } # $1:path

# Function for setting the mode bit
set_mode()
{
    workpath=$1

    # The file is not owned by the user. Skip
    if [[ ! -O "$workpath" ]]; then
        echo_warn "$workpath" "not owned by the user"

    # The file is a directory.
    elif [[ -d "$workpath" ]]; then
        if [[ $verbose -eq 1 ]]; then
            echo_success "$workpath" $modebit_dir " (directory)"; fi

        chmod $modebit_dir "$workpath"

    # The file is an executable file.
    elif [[ $enable_execscan -eq 1 ]] && [[ $(file "$workpath") =~ (executable) ]]; then
        if [[ $verbose -eq 1 ]]; then
            echo_success "$workpath" $modebit_exec " (executable)"; fi

        chmod $modebit_exec "$workpath"

    # The file is a regular file.
    elif [[ -f "$workpath" ]]; then
        if [[ $verbose -eq 1 ]]; then
            echo_success "$workpath" $modebit_file; fi

        chmod $modebit_file "$workpath"

    # The file is a symbolic link. Skip
    elif [[ -h "$workpath" ]]; then
        echo_warn "$workpath" "a symbolic link"

    # The file is a device file. Skip
    elif [[ -b "$workpath" ]] || [[ -c "$workpath" ]]; then
        echo_warn "$workpath" "a device file"

    # The file is a named pipe (FIFO). Skip
    elif [[ -p "$workpath" ]]; then
        echo_warn "$workpath" "a named pipe"

    # Nevermind
    elif [[ -e "$workpath" ]]; then
        echo_warn "$workpath" "undefined"

    # Nevermind
    else
        echo_warn_not_found "$workpath"

    fi
}

find_exec()
{
    find "$@" -exec bash -c 'for workpath do set_mode "$workpath"; done' sh {} +
}

# Export the functions to use them in the inherited function
export -f echo_success
export -f echo_warn
export -f echo_warn_not_found
export -f echo_error_not_found
export -f set_mode


#
# Main
#

# Argument has been provided
if [[ $# -gt 0 ]]; then

    # Check that all the arguments are the valid path
    find "$@" -exec bash -c '
        for filepath do
            if [[ ! -e "$filepath" ]]; then
                echo_error_not_found "$filepath"
                exit 2
            fi
        done
    ' sh {} +

    if [[ $? -eq 0 ]]; then
        find_exec "$@"; fi

# No arguments provided.
else
    find_exec .

fi