Shell script condition judgment

1. String judgment

STR1 = str2 When two strings have the same content, length is true
Str1! = str2 True when string str1 and str2 are not equal
-N str1 True when the length of the string is greater than 0 (string non-null)
-Z str1 True when the string length is 0 (empty string)
STR1 is True when string str1 is not empty

2, the number of the judgment

Int1-eq int2 Two numbers equal to True
Int1-ne Int2 Two number is true
INT1-GT Int2 int1 greater than Int2 is true
Int1-ge Int2 int1 greater than or equal to Int2 true
Int1-lt Int2 int1 Less than Int2 is true
Int1-le Int2 int1 less than or equal to Int2 true

3, the judgment of the document

-r file user readable as True
-W file user can write as true
-X file user can execute as true
-F file is true for regular files
-d file files are directory-True
-C File file is true for character special files
-B file files are true for block special files
-S file files non-0 o'clock True
-T file is true when the specified device is terminal (default = 1)

4. Complex logic judgment

-A and
-O or
! Non -

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Schedule

[-A file] is true if file exists.
[-B file] True if file exists and is a block special file.
[-C file] True if file exists and is a word special.
[-D file] True if file exists and is a directory.
[-E File] True if file exists.
[-F file] True if file exists and is a normal file.
[-G file] True if file exists and Sgid has been set. [-H file] True if file exists and is a symbolic connection.
[-K file] True if file exists and the sticky bit has been set.
[-P file] If file exists and is a name pipe (f if O) is true.
[-R File] True if file exists and is readable.
[-S file] True if file exists and the size is not 0.
[-T FD] true if the file descriptor FD is open and points to a terminal.
[-u file] True if file exists and suid (set user ID) is set.
[-W file] True if file exists and is writable.
[-X file] True if file exists and is executable.
[-o file] True if file exists and is a valid user ID.
[-G file] True if file exists and is a valid user group.
[-L file] True if file exists and is a symbolic connection.
[-N file] If file exists and has been mod if IED since it is last read is true.
[-S file] True if file exists and is a socket.
[File1-nt FILE2] If FILE1 have been changed more recently than FILE2, or if FILE1 exists and FILE2 does not is true.
[File1-ot FILE2] If FILE1 is older than FILE2, or FILE2 exists and FILE1 does not exist, it is true.
[File1-ef FILE2] True if FILE1 and FILE2 point to the same device and node number.
[-O Optionname] true if the shell option "Optionname" is turned on.
[-Z STRING] "STRING" is true if the length is zero.
[-N STRING] or [string] "string" is true if the length is not 0 non-zero.
[STRING1 = = STRING2] If 2 strings are the same. "=" May is used instead of "= =" for strict POSIX compliance is true.
[STRING1! = STRING2] True if the strings are not equal.
[STRING1 < STRING2] if "STRING1" sorts before "STRING2" lexicographically in the current locale is true.
[STRING1 > STRING2] If the ' STRING1 ' sorts after ' STRING2 ' lexicographically in the ' current locale ' is true.

Shell script condition judgment