012#构建shelll脚本库

1. sourcing 功能

   • 使用source、点号(.) 或 exec读入脚本，可使脚本成为了主运行进程
   • 脚本中的命令就好像是直接在当前shell中输入的一样(父shell)

2. 提取前面涉及的函数及全局变量或数组，将其合并到一个文件library.sh中

View Code

#!/usr/bin/env bash
validint(){
  number=$1
  min=$2
  max=$3

  # 空值检测
  if [ -z $number ]; then
    echo "You didn't input anything." >&2
    return 1
  fi
  # 负数符号检测
  if [ "${number%${number#?}}" = "-" ]; then
    num="${number#?}"
  else
    num="${number}"
  fi

  # 检查除负数符号后的数字是否是整数
  nodigits=$(echo $num | sed 's/[[:digit:]]//g')
  if [ ! -z "$nodigits" ]; then
    echo "Invalid number format. Only digits, no commas, spaces, etc." >&2
    return 1
  fi

  # 判断输入值是否小于指定最小值
  if [ ! -z $min ]; then
    if [ $number -lt $min  ]; then
      echo "You value is too small. the smallest value is $min" >&2
      return 1
    fi
  fi

  # 判断输入值是否大于指定最大值
  if [ ! -z $max ]; then
    if [ $number -gt $max ]; then
      echo "You value is too big. the largest value is $max" >&2
      return 1
    fi
  fi

  return 0
}

inpath() {
  cmd=$1
  ourpath=$2
  result=1
  oldIFS=$IFS
  IFS=":"

  for dir in $ourpath; do
    if [ -x $dir/$cmd ]; then
      result=0
    fi 
  done

  IFS=$oldIFS
  return $result
}

checkForCmdInPath() {
  var=$1
  if [ $var != "" ]; then
    if [ ${var%${var#?}} = "/" ]; then
      if [ ! -x $var ]; then
        return 1
      fi
    elif ! inpath $var "$PATH"; then
      return 2
    fi
  fi
}


# 判断给定月份的有效天数
exceedsDaysInMonth()
{
  case $(echo $1 | tr '[:upper:]' '[:lower:]') in
    jan* ) days=31 ;;
    feb* ) days=28 ;;
    mar* ) days=31 ;;
    apr* ) days=30 ;;
    may* ) days=31 ;;
    jun* ) days=30 ;;
    jul* ) days=31 ;;
    aug* ) days=31 ;;
    sep* ) days=30 ;;
    oct* ) days=31 ;;
    nov* ) days=30 ;;
    dec* ) days=31 ;;
    * ) echo "$0: Unkown month name $1" >&2
        exit 1
  esac
  
  # 判断天数是否有效，有效返回0，无效返回1
  if [ $2 -lt 1 -o $2 -gt $days ]; then
    return 1
  else
    return 0
  fi
}

# 验证闰年
isLeapYear()
{
  year=$1
  if [ "$((year%4))" -eq 0 -a "$((year%100))" -ne 0 ]; then
    return 0
  elif [ "$((year%400))" -eq 0 ]; then
    return 0
  else
    return 1
  fi
}
# 规范日期
normaldate()
{
newdate="$(normdate "$@")"
if [ $? -eq 1 ]; then
  exit 1
fi

# 拆分规范后的日期格式，检验其合法有效性
month="$(echo $newdate | cut -d  -f1)"
day="$(echo $newdate | cut -d  -f2)"
year="$(echo $newdate | cut -d  -f3)"

msg1="$0: $3 is not a leap year, so Feb doesn't have 29 days."
msg2="$0: bad day value: $month does't have $2 days."

if ! exceedsDaysInMonth $month $2; then
  if [ "$month" = "Feb" -a $2 -eq 29 ]; then
    if ! isLeapYear $3; then
      echo $msg1 >&2
      exit 1
    fi
  else
    echo $msg2 >&2
    exit 1
  fi
fi
}

# echon()
echon()
{
  echo -e "$*" | awk '{printf("%s", $0)}'
}

# initializeANSI()
initializeANSI()
{
  esc="e"
  # 前景色：
  blackf="${esc}[30m";
  redf="${esc}[31m";
  greenf="${esc}[32m";
  yellowf="${esc}[33m";
  bluef="${esc}[34m";
  purplef="${esc}[35m";
  cyanf="${esc}[36m";
  whitef="${esc}[37m";

  # 背景色：
  blackb="${esc}[40m";
  redb="${esc}[41m";
  greenb="${esc}[42m";
  yellowb="${esc}[43m";
  blueb="${esc}[44m";
  purpleb="${esc}[45m";
  cyanb="${esc}[46m";
  whiteb="${esc}[47m";

  # 粗体、斜体、下划线以及样式切换：
  boldon="${esc}[1m";
  boldoff="${esc}[22m";
  italicson="${esc}[3m";
  italicsoff="${esc}[23m";
  ulon="${esc}[4m";
  uloff="${esc}[24m";
  invon="${esc}[7m"; # 反色，前景色与背景色互换
  invoff="${esc}[27m";
  reset="${esc}[0m" 
}

3. 创建测试脚本library-test读入库文件library.sh，并调用其中的函数

View Code

#!/bin/bash
# library-test
# 读入文件library.sh
. library.sh

initializeANSI

echon "First off, do you have echo in you path?(1=yes, 2=no)"
read answer
while ! validint $answer 1 2; do
  echon  "${boldon}Try again${boldoff}. Do you have echo "
  echon "in you path?(1=yes, 2=no) "
read answer
done

if ! checkForCmdInPath "echo"; then
  echo "Nope, can't find the echo command."
else
  echo "The echo comman is in the PATH."
fi

echo ""

echon "Enter a year you think might be a leep year:"
read year

while ! validint $year 1 9999; do
  echon "Please enter a year in the ${boldon}correct${bolldoff}format: "
done

if isLeapYear $year; then
  echo -e "${greenf}You're right! ${year} is a leap year.${reset}"
else
  echo -e "${redf}Nope, that is not a leap year.${reset}"
fi
exit 0

4. 验证结果：