linux shell 编程学习总结

1 文件和数组

1.1 读文件并将文件内容保存到数组，遍历数组

src.f文件内容

./src/xxx_1.md
./src/xxx_2.md
./src/xxx_3.md
./src/xxx_4.md
./src/xxx_5.md

run.sh

#!/bin/bash

### read flist to array
src_array=()
while read line; do
    src_array+=("$line")
done < $1

### print array
i=1
for itm in "${src_array[@]}"; do
    printf "line $i content: %s\n" "$itm"
    ((i++))
done

exit

运行run.sh结果

2 流程控制语句

2.1 判断文件和路径是否存在

run.sh

if [[ -e "$1" ]]; then
    echo "The file $1 exits."
else
    echo "The file $1 does not exist."
fi

if [[ ! -d "$2" ]]; then
    echo "The dir $2 does not exit."
else
    echo "The dir $2 exists."
fi

运行结果

2.2 逻辑判断

*run.sh

_str="hello world"
_int=996

if [[ "$_str" == "hello world" ]]; then
    echo "String Yes"
else
    echo "String No"
fi

if [[ $_int != 996 ]]; then
    echo "Int No"
else
    echo "Int Yes"
fi

运行结果

3 shell 用户命令行参数处理

3.1 不带option

run.sh

func_print_usage(){
    echo ""
    echo "Usage: run.sh <user> <age> <is_ICer>"
    echo ""
}

if [[ $# != 3 ]]; then
    func_print_usage
elif [[ "$3" != "yes" ]]; then
    echo ""
    echo "You should be good good study for IC"
    echo ""
else
    echo ""
    echo "user:    $1"
    echo "age:     $2"
    echo "is_ICer: $3"
    echo ""
fi

运行结果1

运行结果2

运行结果3

3.2 带option

run.sh

func_help(){
    printf "\n\n  Usage:\n"
    printf "    -h|--help          : Help usage\n"
    printf "    -f|--file <arg>    : Specify file\n"
    printf "    -d|--debug         : Debug mode on\n\n"
}


SHORTOPTS="h,f:,d"
LONGOPTS="help,file:,debug"
ARGS=$(getopt --options $SHORTOPTS --longoptions $LONGOPTS -- "$@")
eval set -- "$ARGS"
while true; do
    case $1 in
        -h|--help)
            func_help
            shift
            exit
            ;;
        -f|--file)
            echo "file: $2"
            shift 2
            ;;
        -d|--debug)
            echo "debug"
            shift
            ;;
        --)
            shift
            break
            ;;
    esac

done

运行结果1

运行结果2

运行结果3

运行结果4

运行结果5

4 shell 函数

run.sh

func_1(){
    echo ""
    echo "func name: $0"
    echo "agc1:      $1"
    echo "agc2:      $2"
    echo "agc3:      $3"
    echo "agc4:      $4"
}


func_2(){
    echo "Will be call func_1"
    func_1 123 "hello world" "" 996
}

echo ""
func_2
echo ""

运行结果