( EXPRESSION )
EXPRESSION is true EXPRESSION为真
! EXPRESSION
EXPRESSION is false EXPRESSION为假
EXPRESSION1 -a EXPRESSION2
both EXPRESSION1 and EXPRESSION2 are true 两者都为真
EXPRESSION1 -o EXPRESSION2
either EXPRESSION1 or EXPRESSION2 is true 其中一个为真
-n STRING
the length of STRING is nonzero 字符串长度非0
STRING equivalent to -n STRING
-z STRING
the length of STRING is zero 字符串长度为0
STRING1 = STRING2
the strings are equal 字符串相等
STRING1 != STRING2
the strings are not equal 字符串不相等
INTEGER1 -eq INTEGER2
INTEGER1 is equal to INTEGER2 INTEGER1等于INTEGER2
INTEGER1 -ge INTEGER2
INTEGER1 is greater than or equal to INTEGER2 INTEGER1大于等于INTEGER2
INTEGER1 -gt INTEGER2
INTEGER1 is greater than INTEGER2 INTEGER1大于INTEGER2
INTEGER1 -le INTEGER2
INTEGER1 is less than or equal to INTEGER2 INTEGER1小于等于INTEGER2
INTEGER1 -lt INTEGER2
INTEGER1 is less than INTEGER2 INTEGER1小于INTEGER2
INTEGER1 -ne INTEGER2
INTEGER1 is not equal to INTEGER2 INTEGER1不等于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 文件存在且为块特殊文件
-c FILE
FILE exists and is character special 文件存在且为字符特殊文件
-d FILE
FILE exists and is a directory 文件存在且为目录
-e FILE
FILE exists 文件存在
-f FILE
FILE exists and is a regular file 文件存在且为正规文件
-g FILE
FILE exists and is set-group-ID 文件存在且已设置组ID
-G FILE
FILE exists and is owned by the effective group ID 文件存在且属组为有效的组ID
-h FILE
FILE exists and is a symbolic link (same as -L) 文件存在且为符号链接
-k FILE
FILE exists and has its sticky bit set 文件存在且已设置sticky-bit权限
-L FILE
FILE exists and is a symbolic link (same as -h) 文件存在且为符号链接
-O FILE
FILE exists and is owned by the effective user ID文件存在且属主为有效的用户ID
-p FILE
FILE exists and is a named pipe
-r FILE
FILE exists and read permission is granted 文件存在且可读
-s FILE
FILE exists and has a size greater than zero 文件存在且大小非0
-S FILE
FILE exists and is a socket 文件存在且是socket文件
-t FD file descriptor FD is opened on a terminal
-u FILE
FILE exists and its set-user-ID bit is set 文件存在且已设置set-user-id bit权限
-w FILE
FILE exists and write permission is granted 文件存在且可写
-x FILE
FILE exists and execute (or search) permission is granted 文件存在且可执行