如何确定我正在使用的当前shell ?

仅仅ps命令的输出就足够了吗?

如何在不同风格的Unix中实现这一点?


当前回答

Try

ps -p $$ -oargs=

or

ps -p $$ -ocomm=

其他回答

你可以试试:

ps | grep `echo $$` | awk '{ print $4 }'

Or:

echo $SHELL

Ps -p $$

应该在涉及ps -ef和grep的解决方案的任何地方工作(在任何支持POSIX选项的ps的Unix变体上),并且不会受到grepping对可能出现在其他地方的数字序列引入的误报的影响。

这不是一个非常干净的解决方案,但它是你想要的。

# MUST BE SOURCED..
getshell() {
    local shell="`ps -p $$ | tail -1 | awk '{print $4}'`"

    shells_array=(
    # It is important that the shells are listed in descending order of their name length.
        pdksh
        bash dash mksh
        zsh ksh
        sh
    )

    local suited=false
    for i in ${shells_array[*]}; do
        if ! [ -z `printf $shell | grep $i` ] && ! $suited; then
            shell=$i
            suited=true
        fi
    done

    echo $shell
}
getshell

现在您可以使用$(getshell)——version。

不过,这只适用于kornshell类shell (ksh)。

如果你只是想确保用户正在使用Bash调用脚本:

if [ -z "$BASH" ]; then echo "Please run this script $0 with bash"; exit; fi

或参考

if [ -z "$BASH" ]; then exec bash $0 ; exit; fi

There are three approaches to finding the name of the current shell's executable: Please note that all three approaches can be fooled if the executable of the shell is /bin/sh, but it's really a renamed bash, for example (which frequently happens). Thus your second question of whether ps output will do is answered with "not always". echo $0 - will print the program name... which in the case of the shell is the actual shell. ps -ef | grep $$ | grep -v grep - this will look for the current process ID in the list of running processes. Since the current process is the shell, it will be included. This is not 100% reliable, as you might have other processes whose ps listing includes the same number as shell's process ID, especially if that ID is a small number (for example, if the shell's PID is "5", you may find processes called "java5" or "perl5" in the same grep output!). This is the second problem with the "ps" approach, on top of not being able to rely on the shell name. echo $SHELL - The path to the current shell is stored as the SHELL variable for any shell. The caveat for this one is that if you launch a shell explicitly as a subprocess (for example, it's not your login shell), you will get your login shell's value instead. If that's a possibility, use the ps or $0 approach. If, however, the executable doesn't match your actual shell (e.g. /bin/sh is actually bash or ksh), you need heuristics. Here are some environmental variables specific to various shells: $version is set on tcsh $BASH is set on bash $shell (lowercase) is set to actual shell name in csh or tcsh $ZSH_NAME is set on zsh ksh has $PS3 and $PS4 set, whereas the normal Bourne shell (sh) only has $PS1 and $PS2 set. This generally seems like the hardest to distinguish - the only difference in the entire set of environment variables between sh and ksh we have installed on Solaris boxen is $ERRNO, $FCEDIT, $LINENO, $PPID, $PS3, $PS4, $RANDOM, $SECONDS, and $TMOUT.