Question

当我使用

时，我有一个已存在于目录中的文件测试

  `cat > test` or `ls > test`

文件中的内容将被截断，数据将丢失，所以我想在重定向文件之前提示一条提示信息。你的帮助最有用。

提前致谢。

Answer 1

可能是一个例子：

#!/bin/sh

# Prevent > from overwriting files, use >| to overwrite files anyway
# It's good for safety to always enable this...
set -C

file=xxx

# Test if file exist with -f
if [ -f "$file" ]; then
    echo "Overwrite $file? [Y/n]"

    # Read user input
    read answer

    # Is the answer "n" or "N", we exit
    # The default is to continue on any other input (you could change this, of course)
    case "$answer" in
        [nN]) exit 2 ;;
    esac
fi

# Overwrite the file, we use >| because we set noclobber
echo 'New' >| "$file"

重定向文件时如何获取提示信息？

1 个答案: