请问下面这段条件句意义

gaowudi

# .bash_profile

# Get the aliases and functions
if [ -f ~/.bashrc ]; then
        . ~/.bashrc
fi

##### 这里 -f 这个参数是什么意思？   好像除了 -f 之外 还有 x ,z 等等，他们都是什么意思呢
##### 还有 ~/.bashrc, 的 ~ 是什么含意？

# User specific environment and startup programs

JAVA_HOME=/usr/java/j2sdk1.4.2_09
CLASS_PATH=.JAVA_HOME/lib/dt.jarJAVA_HOME/lib/tools.jar
PATH=$JAVA_HOME/binHOME/binPATH

export JAVA_HOME
export CLASS_PATH
export PATH
unset USERNAME


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初学者问题，谢谢指教。

troll

help test

简单说就是家目录

kevein2

-f 我觉得可能是检查文件是否为普通文件（也就是说不是文件夹）
~应该是指家目录，也就是/HOME
我也是新手，不知道对不对，清高说指点

chongling

-f 是用来测试一个文件是否存在并且是否是常规文件
~/.bash_rc 是指你的Home目录下的.bash_rc文件

loosy929

Understanding following three types of conditions tests will be good for you
When you login(bash), your .bash_profile will be read, if you define some alias, etc. in your .bashrc, here is a way for it to be invoked.

1. String comparisons
-n str1
str1 is not null (has length greater than 0)
-z str1
str1 is null (has length 0)

2. File checking
-d file
file exists and is a directory

-e file
file exists

-f file
file exists and is a regular file (i.e., not a directory or other special type of file)

-r file
You have read permission on file

-s file
file exists and is not empty

-w file
You have write permission on file

-x file
You have execute permission on file, or directory search permission if it is a directory

-O file
You own file

-G file
file's group ID matches yours (or one of yours, if you are in multiple groups).

file1 -nt file2
file1 is newer than file2a

file1 -ot file2
file1 is older than file2

3.Integer Conditionals
-lt
Less than

-le
Less than or equal

-eq
Equal

-ge
Greater than or equal

-gt
Greater than

-ne
Not equal