测试多个文件条件一举（BASH）？ [英] Test multiple file conditions in one swoop (BASH)?

问题描述

常为bash shell的写作时，需要测试，如果一个文件（或目录）的存在（或不存在），并采取适当的行动。最常见的在这些测试都是...

Often when writing for the bash shell, one needs to test if a file (or Directory) exists (or doesn't exist) and take appropriate action. Most common amongst these test are...

-e - 文件存在， -f - 文件是一个普通文件（不是目录或设备文件）， -s - 文件不为零的大小， -d - 文件是一个目录， -r - 文件读取权限， -w - 文件写入，或者 -x 执行权限（运行测试用户）

-e - file exists, -f - file is a regular file (not a directory or device file), -s - file is not zero size, -d - file is a directory, -r - file has read permission, -w - file has write, or -x execute permission (for the user running the test)

这是很容易这样的用户可写目录作为证明证实 ...

This is easily confirmed as demonstrated on this user-writable directory....

#/bin/bash

if [ -f "/Library/Application Support" ]; then
echo 'YES SIR -f is fine'
else echo 'no -f for you'
fi

if [ -w "/Library/Application Support" ]; then
echo 'YES SIR -w is fine'
else echo 'no -w for you'
fi

if [ -d "/Library/Application Support" ]; then
echo 'YES SIR -d is fine'
else echo 'no -d for you'
fi

➝没有-f你✓结果
➝YES SIR -w是罚款✓结果
➝YES SIR -d是罚款✓

我的问题，虽然看似明显，而不太可能是不可能的 - 是如何简单的合并的这些测试，而无需分别执行他们每个条件。可惜​​......

My question, although seemingly obvious, and unlikely to be impossible - is how to simply combine these tests, without having to perform them separately for each condition... Unfortunately...

if [ -wd "/Library/Application Support" ]  
  ▶  -wd: unary operator expected

if [ -w | -d "/Library/Application Support" ]   
  ▶  [: missing `]'
  ▶  -d: command not found

if [ -w [ -d "/Library.... ]]   &  if [ -w && -d "/Library.... ] 
  ▶  [: missing `]'

➝没有-wd你✖结果
➝没有-w | -d你✖结果
➝没有[-w [-d ..]你✖结果
➝没有-w和放大器;＆安培; -d你✖

我缺少的是在这里吗？

What am I missing here?

推荐答案

您可以使用逻辑运算符将多个条件，例如 -a 为和：

You can use logical operators to multiple conditions, e.g. -a for AND:

MYFILE=/tmp/data.bin
if [ -f "$MYFILE"  -a  -r "$MYFILE"  -a  -w "$MYFILE" ]; then
    #do stuff
fi
unset MYFILE

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