bash脚本在Linux中参数解析 [英] Bash Script with Parsing Argument in Linux

问题描述

我想要写一个bash脚本：

I want to write a bash script :

schedsim.sh [-h] [-c x] -i pathfile

其中：

•-h：打印当前用户名。

• -h: print the current username.

•-c X：得到一个选项参数x和打印出（X + 1）。如果没有找到说法，打印默认值为1。

• -c x : get an option-argument x and print out (x + 1). If no argument was found, print the default value is 1.

•-i pathfile：打印pathfile的大小。该pathfile是必需的参数。如果发现任何参数，打印出的错误消息。

• -i pathfile: print the size of pathfile. The pathfile is a required argument. If no argument was found, print out an error message.

这是我迄今所做的：

x=""
path=""
while getopts ":hc:i:" Option
do
case $Option in
h) echo -e "$USER\n"
;;
c) x=$optarg+1
;;
i) path=$(wc -c <"$optarg")
;;
esac
done

if [ -z "$x"] 
then
 echo -e "$x\n"
else
 echo 1
fi

if [ -z "$path"] 
then
 echo $path
else
 echo "Error Message"
 exit 1
fi

如何完成选项参数，所需参数的部分和错误信息的一部分？

How to finish the option-argument,required-argument part and the error message part?

推荐答案

一个重写：

while getopts ":hc:i:" Option; do
    case $Option in
        h)  echo "$USER"
            ;;
        c)  x=$(($OPTARG + 1))
            ;;
        i)  if [[ -f $OPTARG ]]; then
                size=$(wc -c <"$OPTARG")
            else
                echo "error: no such file: $OPTARG"
                exit 1
            fi 
            ;;
    esac
done

if [[ -z $x ]]; then
    echo "you used -c: the result is $x"
fi

if [[ -z $size ]]; then
    echo "you used -i: the file size is $size"
fi

注：

• OPTARG 必须是大写。


• 您需要 $（（...））对于bash算术


• 检查该文件在使用它之前存在


• 使用一个明智的文件名（路径不会重新present一个文件的大小）


• 有必须的是一个空格]



• 回声-e值\\ N是太多的工作：你只是想回声值除非你要处理的值转义序列：

• OPTARG must be in upper case.
• you need $((...)) for bash arithmetic
• check that the file exists before using it
• use a sensible filename (path does not represent the size of a file)
• there must be a space before ]

• echo -e "value\n" is too much work: you just want echo "value" unless you want to process escape sequences in the value:

$ var="foo\tbar\rbaz"
$ echo "$var"
foo\tbar\rbaz
$ echo -e "$var\n"
baz bar

$ 

更新：回复评论：简化和更完整的选项处理;扩展错误处理。

Update: responding to comments: simplified and more complete option handling; expanded error handling.

#!/bin/bash
declare -A given=([c]=false [i]=false)
x=0
path=""

while getopts ":hc:i:" Option; do
    case $Option in
        h)  echo "$USER"
            ;;
        c)  x=$OPTARG
            given[c]=true
            ;;
        i)  path=$OPTARG
            given[i]=true
            ;;
        :)  echo "error: missing argument for option -$OPTARG"
            exit 1
            ;;
        *)  echo "error: unknown option: -$OPTARG"
            exit 1
            ;;
    esac
done

# handle $x
if [[ ! $x =~ ^[+-]?[[:digit:]]+$ ]]; then
    echo "error: your argument to -c is not an integer"
    exit 1
fi
if ! ${given[c]}; then
    printf "using the default value: "
fi
echo $(( 10#$x + 1 ))

# handle $path
if ! ${given[i]}; then
    echo "error: missing mandatory option: -i path"
    exit 1
fi
if ! [[ -f "$path" ]]; then
    echo "error: no such file: $path"
    exit 1
fi
echo "size of '$path' is $(stat -c %s "$path")"

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