test (检查文件类型)

rose1 发表于 2020-07-27 17:41

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命令行 Unix&Linux命令 test

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在类似Unix的操作系统上，test命令检查文件类型并比较值。本文档介绍了GNU / Linux版本的测试。

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1 test 运行系统环境

2 test 说明

3 test 语法

4 test 例子

test 运行系统环境

Linux

test 说明

测试用作有条件执行Shell命令的一部分。

测试以EXPRESSION确定的状态退出。将EXPRESSION放在方括号（[和]）之间与使用test测试EXPRESSION相同。要在命令提示符下查看退出状态，请回显值“ $？ ”。值0表示表达式的值为true，值为1表示表达式的值为false。

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test 语法

test EXPRESSION

[ EXPRESSION ]

表达方式

表达式采用以下形式：

( EXPRESSION )	表达是真的
! EXPRESSION	表达式为假
EXPRESSION1 -a EXPRESSION2	这两个表达式和表达式2为真
EXPRESSION1 -o EXPRESSION2	无论是表达式或表达式2为真
-n STRING	STRING的长度不为零
STRING	等效于-n STRING
-z STRING	STRING的长度为零
STRING1 = STRING2	字符串相等
STRING1 != STRING2	字符串不相等
INTEGER1 -eq INTEGER2	INTEGER1等于INTEGER2
INTEGER1 -ge INTEGER2	INTEGER1大于或等于INTEGER2
INTEGER1 -gt INTEGER2	INTEGER1大于INTEGER2
INTEGER1 -le INTEGER2	INTEGER1小于或等于INTEGER2
INTEGER1 -lt INTEGER2	INTEGER1小于INTEGER2
INTEGER1 -ne INTEGER2	INTEGER1不等于INTEGER2
FILE1 -ef FILE2	FILE1和FILE2具有相同的设备和inode编号
FILE1 -nt FILE2	FILE1比FILE2更新（修改日期）
FILE1 -ot FILE2	FILE1早于FILE2
-b FILE	FILE存在且块特殊
-c FILE	FILE存在且字符特殊
-d FILE	FILE存在并且是目录
-e FILE	FILE存在
-f FILE	FILE存在并且是常规文件
-g FILE	FILE存在且为set-group-ID
-G FILE	FILE存在并且由有效组ID拥有
-h FILE	FILE存在并且是符号链接（与-L相同）
-k FILE	FILE存在并且已设置其粘性位
-L FILE	FILE存在并且是符号链接（与-h相同）
-O FILE	FILE存在并且由有效用户ID拥有
-p FILE	FILE存在并且是一个命名管道
-r FILE	FILE存在并且授予读取权限
-s FILE	FILE存在且大小大于零
-S FILE	FILE存在并且是一个套接字
-t FD	在终端上打开文件描述符FD
-u FILE	FILE存在，并且其设置用户ID位置1
-w FILE	FILE存在并且授予写权限
-x FILE	FILE存在并授予执行（或搜索）权限

除了-h和-L以外，所有与FILE相关的测试都取消引用符号链接。请注意，对于shell，括号需要转义（例如，用反斜杠）。INTEGER也可以是-l STRING，其值为STRING的长度。

注意：您的外壳可能具有自己的test版本，通常会取代此处描述的版本。请参阅您的Shell文档以获取有关其支持的选项的详细信息。

test EXPRESSION

[ EXPRESSION ]

Expressions

Expressions take the following forms:

( EXPRESSION )	EXPRESSION is true
! EXPRESSION	EXPRESSION is false
EXPRESSION1 -a EXPRESSION2	both EXPRESSION1 and EXPRESSION2 are true
EXPRESSION1 -o EXPRESSION2	either EXPRESSION1 or EXPRESSION2 is true
-n STRING	the length of STRING is nonzero
STRING	equivalent to -n STRING
-z STRING	the length of STRING is zero
STRING1 = STRING2	the strings are equal
STRING1 != STRING2	the strings are not equal
INTEGER1 -eq INTEGER2	INTEGER1 is equal to INTEGER2
INTEGER1 -ge INTEGER2	INTEGER1 is greater than or equal to INTEGER2
INTEGER1 -gt INTEGER2	INTEGER1 is greater than INTEGER2
INTEGER1 -le INTEGER2	INTEGER1 is less than or equal to INTEGER2
INTEGER1 -lt INTEGER2	INTEGER1 is less than INTEGER2
INTEGER1 -ne INTEGER2	INTEGER1 is not equal to INTEGER2
FILE1 -ef FILE2	FILE1 and FILE2 have the same device and inode numbers
FILE1 -nt FILE2	FILE1 is newer (modification date) than FILE2
FILE1 -ot FILE2	FILE1 is older than FILE2
-b FILE	FILE exists and is block special
-c FILE	FILE exists and is character special
-d FILE	FILE exists and is a directory
-e FILE	FILE exists
-f FILE	FILE exists and is a regular file
-g FILE	FILE exists and is set-group-ID
-G FILE	FILE exists and is owned by the effective group ID
-h FILE	FILE exists and is a symbolic link (same as -L)
-k FILE	FILE exists and has its sticky bit set
-L FILE	FILE exists and is a symbolic link (same as -h)
-O FILE	FILE exists and is owned by the effective user ID
-p FILE	FILE exists and is a named pipe
-r FILE	FILE exists and read permission is granted
-s FILE	FILE exists and has a size greater than zero
-S FILE	FILE exists and is a socket
-t FD	file descriptor FD is opened on a terminal
-u FILE	FILE exists and its set-user-ID bit is set
-w FILE	FILE exists and write permission is granted
-x FILE	FILE exists and execute (or search) permission is granted

Except for -h and -L, all FILE-related tests dereference symbolic links. Beware that parentheses need to be escaped (e.g., by backslashes) for shells. INTEGER may also be -l STRING, which evaluates to the length of STRING.

NOTE: your shell may have its own version of test, which usually supersedes the version described here. Please refer to your shell's documentation for details about the options it supports.

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test 例子

test 100 -gt 99 && echo "Yes, that's true." || echo "No, that's false."

因为100大于99，所以此命令将打印文本“ 是的，是的” 。

test 100 -lt 99 && echo "Yes." || echo "No."

该命令将打印文本“ No. ”，因为100不少于99。

[ "awesome" = "awesome" ]; echo $?

该命令将打印“ 0 ”，因为该表达式为真；这两个字符串是相同的。

[ 5 -eq 6 ]; echo $?

该命令将打印“ 1 ”，因为表达式为假；否则为0。5不等于6。

test 100 -gt 99 && echo "Yes, that's true." || echo "No, that's false."

This command will print the text "Yes, that's true." because 100 is greater than 99.

test 100 -lt 99 && echo "Yes." || echo "No."

This command will print the text "No." because 100 is not less than 99.

[ "awesome" = "awesome" ]; echo $?

This command will print "0" because the expression is true; the two strings are identical.

[ 5 -eq 6 ]; echo $?

This command will print "1" because the expression is false; 5 does not equal 6.

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其他命令行

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