AMiRo-OS

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# GENERIC FUNCTIONS                                                            #

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### print an error message #####################################################

# Prints a error <message> to standard output.

#If variable 'LOG_FILE' is specified, the message is also appended to the given file.

#

# usage:      printError <message>

# arguments:  <message>

#                 Message string to print.

# return:     n/a

#

function printError {

  local string="ERROR:   $1"

  # if a log file is specified

  if [ -n "$LOG_FILE" ]; then

    printf "[$(date '+%Y-%m-%d %H:%M:%S')] $string" >> $LOG_FILE

  fi

  printf "$(tput setaf 1)>>> $string$(tput sgr 0)" 1>&2

}

### print a warning message ####################################################

# Prints a warning <message> to standard output.

#If variable 'LOG_FILE' is specified, the message is also appended to the given file.

#

# usage:      printMessage <message>

# arguments:  <message>

#                 Message string to print.

# return:     n/a

#

function printWarning {

  local string="WARNING: $1"

  # if a log file is specified

  if [ -n "$LOG_FILE" ]; then

    printf "[$(date '+%Y-%m-%d %H:%M:%S')] $string" >> $LOG_FILE

  fi

  printf "$(tput setaf 3)>>> $string$(tput sgr 0)"

}

### print an information message ###############################################

# Prints an information <message> to standard output.

#If variable 'LOG_FILE' is specified, the message is also appended to the given file.

#

# usage:      printInfo <message>

# arguments:  <message>

#                 Message string to print.

# return:     n/a

#

function printInfo {

  local string="INFO:    $1"

  # if a log file is specified

  if [ -n "$LOG_FILE" ]; then

    printf "[$(date '+%Y-%m-%d %H:%M:%S')] $string" >> $LOG_FILE

  fi

  printf "$(tput setaf 2)>>> $string$(tput sgr 0)"

}

### print a message to file ####################################################

# Appends a <message> to a log file, specified by the variable 'LOG_FILE'.

#

# usage       printLog <message>

# arguments:  <message>

#                 Message string to print.

# return:     n/a

#

function printLog {

  local string="LOG:     $1"

  # if a log file is specified

  if [ -n "$LOG_FILE" ]; then

    printf "[$(date '+%Y-%m-%d %H:%M:%S')] $string" >> $LOG_FILE

  fi

}

### exit the script normally ###################################################

# Prints a delimiter and exits the script normally (returns 0).

#

# usage:      quitScript

# arguments:  n/a

# return:     0

#                 No error or warning occurred.

#

function quitScript {

  printInfo "exiting $(realpath ${BASH_SOURCE[0]})\n"

  printf "\n"

  printf "######################################################################\n"

  exit 0

}

### read a user input ##########################################################

# Reads a single character user input from a set up <options> and stores it in

# a given <return> variable.

#

# usage:      readUserInput <options> <return>

# arguments:  <options>

#                 String definiing the set of valid characters.

#                 If the string is empty, the user can input any character.

#             <return>

#                 Variable to store the selected character to.

# return:     n/a

#

function readUserInput {

  local input=""

  # read user input

  while [ -z $input ] || ( [ -n "$1" ] && [[ ! $input =~ ^[$1]$ ]] ); do

    read -p "your selection: " -n 1 -e input

    if [ -z $input ] || ( [ -n "$1" ] && [[ ! $input =~ ^[$1]$ ]] ); then

      printWarning "[$input] is no valid action\n"

    fi

  done

  printLog "[$input] has been selected\n"

  eval $2="$input"

}

### check whether argument is an option ########################################

# Checks a <string> whether it is an option.

# Options are defined to either start with '--' followed by any string, or

# to start with a single '-' followed by a single character, or

# to start with a single '-' followed by a single character, a '=' and any string.

# Examples: '--option', '--option=arg', '-o', '-o=arg', '--'

#

# usage:      parseIsOption <string>

# arguments:  <string>

#                 A string to check whether it is an option.

# return:     0

#                 <string> is an option.

#             -1

#                 <string> is not an option.

#

function parseIsOption {

  if [[ "$1" =~ ^-(.$|.=.*) ]] || [[ "$1" =~ ^--.* ]]; then

    return 0

  else

    return -1

  fi

}

### set the log file ###########################################################

# Sets a specified <infile> as log file and checks whether it already exists.

# If so, the log may either be appended to the file, its content can be cleared,

# or no log is generated at all.

# The resulting path is stored in <outvar>.

#

# usage:      setLogFile [--option=<option>] [--quiet] <infile> <outvar>

# arguments:  --option=<option>

#                 Select what to do if <file> already exists.

#                 Possible values are 'a', 'c', 'r' and 'n'.

#                 - a: append (starts with a separator)

#                 - c: continue (does not insert a seperator)

#                 - r: delete and restart

#                 - n: no log

#                 If no option is secified but <file> exists, an interactive selection is provided.

#             --quiet

#                 Suppress all messages.

#             <infile>

#                 Path of the wanted log file.

#             <outvar>

#                 Variable to store the path of the log file to.

# return:     0

#                 No error or warning occurred.

#             -1

#                 Error: invalid input

#

function setLogFile {

  local filepath=""

  local option=""

  local quiet=false

  # parse arguments

  local otherargs=()

  while [ $# -gt 0 ]; do

    if ( parseIsOption $1 ); then

      case "$1" in

        -o=*|--option=*)

          option=${1#*=}; shift 1;;

        -o*|--option*)

          option="$2"; shift 2;;

        -q|--quiet)

          quiet=true; shift 1;;

        *)

          printError "invalid option: $1\n"; shift 1;;

      esac

    else

      otherargs+=("$1")

      shift 1

    fi

  done

  filepath=$(realpath ${otherargs[0]})

  # if file already exists

  if [ -e $filepath ]; then

    # if no option was specified, ask what to do

    if [ -z "$option" ]; then

      printWarning "log file $filepath already esists\n"

      local userinput=""

      printf "Select what to do:\n"

      printf "  [A] - append log\n"

      printf "  [R] - restart log (delete existing file)\n"

      printf "  [N] - no log\n"

      readUserInput "AaRrNn" userinput

      option=${userinput,,}

    fi

    # evaluate option

    case "$option" in

      a|c)

        if [ $quiet = false ]; then

          printInfo "appending log to $filepath\n"

        fi

        if [ $option != c ]; then

          printf "\n" >> $filepath

          printf "######################################################################\n" >> $filepath

          printf "\n" >> $filepath

        fi

        ;;

      r)

        echo -n "" > $filepath

        if [ $quiet = false ]; then

          printInfo "content of $filepath wiped\n"

        fi

        ;;

      n)

        if [ $quiet = false ]; then

          printInfo "no log file will be generated\n"

        fi

        filepath=""

        ;;

      *) # sanity check (return error)

        printError "unexpected argument: $option\n"; return -1;;

    esac

  else

    if [ $quiet = false ]; then

      printInfo "log file set to $filepath\n"

    fi

  fi

  eval ${otherargs[1]}="$filepath"

  return 0

}

### check whether commands are available #######################################

# Checks whether the specified commands are available and can be executed.

#

# usage:      checkCommands [<command> <command> ...]

# arguments:  <command>

#                 Name of the command to check.

# return:     0

#                 All requested commands are available.

#             >0

#                 Number of requested commands that were not found.

#             -1

#                 No argument given.

#

function checkCommands {

  local status=0

  # return if no argument was specified

  if [ $# -eq 0 ]; then

    return -1

  fi

  # check all specified commands

  while [ $# -gt 0 ]; do

    command -v $1 &>/dev/null

    if [ $? -ne 0 ]; then

      printWarning "Command '$1' not available.\n"

      status=$((status + 1))

    fi

    shift 1

  done

  return $status

}

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# SPECIFIC FUNCTIONS                                                           #

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