如何编写bash函数来包装另一个命令? [英] How to write a bash function to wrap another command?

问题描述

我正在尝试为 mysql 命令

如果pwd中存在 .my.cnf ，我想自动将-defaults-file = .my.cnf 附加到命令

If .my.cnf exists in the pwd, I would like to automatically attach --defaults-file=.my.cnf to the command

这就是我正在尝试的

function mysql {
  if [ -e ".my.cnf" ]; then
    /usr/local/bin/mysql --defaults-file=.my.cnf "$@"
  else
    /usr/local/bin/mysql "$@"
  fi
}

想法是，我希望能够像以前一样完全使用 mysql 命令 ，仅在 .my.cnf 文件存在，将其作为参数附加

The idea is, I want to be able to use the mysql command exactly as I was before, only, if the .my.cnf file is present, attach it as an argument

问题:这种方法会遇到任何麻烦吗?有更好的方法吗?

Question: Will I run into any trouble with this method? Is there a better way to do it?

如果我手动指定-defaults-file = foo.cnf ，则应使用它代替 .my.cnf .

If I specify --defaults-file=foo.cnf manually, that should be used instead of .my.cnf.

推荐答案

您编写的函数非常好.这是一个触摸式干燥器:

Your function as written is perfectly fine. This is a touch DRYer:

function mysql {
    if [ -e ".my.cnf" ]; then
        set -- --defaults-file=.my.cnf "$@"
    fi
    /usr/local/bin/mysql "$@"
}

该 set 命令将my.cnf参数放在命令行参数的开头

That set command puts your my.cnf argument at the beginning of the command line arguments

仅当该选项尚不存在时:

Only if the option is not already present:

function mysql {
    if [[ -e ".my.cnf" && "$*" != *"--defaults-file"* ]]; then
        set -- --defaults-file=.my.cnf "$@"
    fi
    /usr/local/bin/mysql "$@"
}

这篇关于如何编写bash函数来包装另一个命令?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！