Question

set命令可用于更改位置参数$ 1 $ 2 ...

的值

但是，有没有办法改变$ 0？

Answer 1

这是另一种方法。它是通过直接命令执行来实现的，这比命令（点命令）要好一些。但是，此方法仅适用于shell解释器，而不适用于bash，因为sh支持-s -c选项一起传递：

#! /bin/sh
# try executing this script with several arguments to see the effect

test ".$INNERCALL" = .YES || {
    export INNERCALL=YES
    cat "$0" | /bin/sh -s -c : argv0new "$@"
    exit $?
}

printf "argv[0]=$0\n"
i=1 ; for arg in "$@" ; do printf "argv[$i]=$arg\n" ; i=`expr $i + 1` ; done

./the_example.sh 1 2 3案例中两个示例的预期输出应为：

argv[0]=argv0new
argv[1]=1
argv[2]=2
argv[3]=3

Answer 2

#! /bin/sh
# try executing this script with several arguments to see the effect

test ".$INNERCALL" = .YES || {
    export INNERCALL=YES
    # this method works both for shell and bash interpreters
    sh -c ". '$0'" argv0new "$@"
    exit $?
}

printf "argv[0]=$0\n"
i=1 ; for arg in "$@" ; do printf "argv[$i]=$arg\n" ; i=`expr $i + 1` ; done

Answer 3

在Bash大于或等于5的情况下，您可以像这样更改$0：

$ cat bar.sh
#!/bin/bash
echo $0
BASH_ARGV0=lol
echo $0
$ ./bar.sh 
./bar.sh
lol

ZSH甚至支持直接分配给0：

$ cat foo.zsh
#!/bin/zsh
echo $0
0=lol
echo $0
$ ./foo.zsh 
./foo.zsh
lol

如何更改shell / bash脚本中的argv [0]值？

3 个答案: