Bash - Utility functions

cmd_line_opt.sh

while getopts ae:f:h:qs: option
do
  case "${option} in 
    a) AFLAG="TRUE"  ;;
    e) EOPTION=${OPTARG}  ;;
    f) FILE=${OPTARG}  ;;
    q) QUIET="TRUE"  ;;
    s) SERVER=${OPTARG}  ;;
    h|\?) usage && exit 1  ;;
  esac
done

factorial.sh

factorial()
{
  count=$1
  fact=1
  while [ ${count} -gt 0 ]; do
    fact=$(( ${fact} * ${count} ))
    count=$(( ${count} - 1 ))
  done
  echo ${fact}
}

read_from_file.sh

#!/bin/bash

FILE=$1

# Read $FILE using fd
exec 3 < &0
exec 0 < ${FILE}
while read line; do
  # Use ${line} to process each line
  echo ${line}
done
exec 0 < &3

util.sh

#!/bin/bash -

set -o nounset

pad_to_size()
{
  local file=${1}
  local size=${2}
  local cur_size=${3}
  local pad_length=$( echo ${size} - ${cur_size} | bc )
  dd if=/dev/zero count=${pad_length} bs=1 >> ${file}
}

# pad_to_size test.txt 512 0
# pad_to_size test.txt 1024 $(stat -c%s test.txt)


_count=0

add_to_file_and_count()
{
  local file=${1}
  local str=${2}
  echo -en "${str}\0" >> ${file}
  _count=$( echo ${_count} + ${#str} + 1 | bc )  # + 1 since i'm adding '\0'
}

# add_to_file_and_count test.txt "Hello"
# add_to_file_and_count test.txt "World"


declare -A SECT1
declare -A SECT2

parse_config_file()
{
  local config_file="${1}"
  eval `awk -F ' *= *' '{ \
    if ($1 ~ /^\[/) \
      { section=$1; gsub(/\[|\]/, "", section); } \
    else if ($1 !~ /^$/) \
      print section"["$1"]" "=" "\"" $2 "\"" }' ${config_file}`
}

# config.txt
# 
# [SECT1]
# val1 = "1"
# val2 = 100
#
# [SECT2]
# id = 0
# name = TEST
#

parse_config_file config.txt
echo ${SECT1[val1]}
echo ${SECT1[val2]}
echo ${SECT2[id]}
echo ${SECT2[name]}