Shell condition judgment

1. string Judgments

STR1 = str2	True when two strings have the same content, length
Str1! = str2	True when strings str1 and str2 are unequal
-N str1	True when the length of a string is greater than 0 (string non-null)
-Z str1	True when the length of the string is 0 (empty string)
Str1	True when the string str1 is non-empty

2. Judgment of numbers

Int1-eq Int2	Two numbers equal to True
Int1-ne Int2	Two numbers are 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. Judgment of documents

-R File	User-readable as true
-W File	User can write as true
-X File	User can perform a true
-F File	File is true for regular files
-D File	File is directory-True
-C file	File is true for character special files
-B File	File is true for block special files
-S file	File non-0 o'clock is true
-T file	True if the specified device is terminal when the file descriptor (default is 1)

4. complex logic judgment

-A	And
-O	Or
!	Non -

[-A FILE] ifFILE exists is true.
[-B FILE] IfFile exists and is a block of special files is true.
[-C FILE] IfFile exists and is a word for special files is true.
[-D FILE] IfFILE exists and is a directory is true.
[-e FILE] IfFILE exists is true.
[-F FILE] IfFile exists and is a normal file is true.
[-G FILE] IfFILE exists and has been setThe Sgid is true.[-H FILE] IfFILE exists and is a symbolic join is true.
[-K FILE] IfTrue if FILE exists and the sticky bit has been set.
[-P FILE] IfFILE exists and is a name pipe(F ifO) is true.
[-R FILE] IfTrue if FILE exists and is readable.
[-S FILE] ifFILE exists and size is not0 is true.
[-T FD] if the file descriptorFD is turned on and pointing to a terminal is true.
[-U FILE] IfFILE exists and is setThe SUID (set user ID) is true.
[-W FILE] IfFILE ifTrue if FILE exists and is writable.
[-X FILE] IfTrue if FILE exists and is executable.
[-O FILE] IfFILE exists and is a valid userThe ID is true.
[-G FILE] IfFILE exists and is valid user group is true.
[-L FILE] IfFILE exists and is a symbolic join is true.
[-N FILE] IfFILE existsand has been mod ifIED since it is last read is true.
[-S FILE] ifFILE exists and is a socket true.
[File1-nt FILE2] IfFILE1 have been changed more recently than FILE2, or ifFILE1 exists and FILE2 does not are true.
[File1-ot FILE2] IfFILE1 ratioFILE2 to be old.OrFILE2 exists andFILE1 is true if it does not exist.
[File1-ef FILE2] IfFILE1 andFILE2 points to the same device and the node number is true.
[-O optionname] IfShell options  "Optionname"   is true.   
[-Z string]  ' string '   is true for a length of zero.   
[-N string] or [string]  "string"   length is not 0   The Non-zero is true.   
[STRING1 = = STRING2]   if 2 strings are the same.   "=" May is used instead of "= =" for strict POSIX compliance is true.   
[STRING1! = STRING2]   If the strings are not equal.  
[STRING1 < STRING2]   if   "STRING1" sorts before " STRING2 "lexicographically in the current locale is true.   
[STRING1 > STRING2]   if   "STRING1" sorts After ' STRING2 ' lexicographically in the current locale is true.  

[-A FILE] ifFILE exists is true.
[-B FILE] IfFile exists and is a block of special files is true.
[-C FILE] IfFile exists and is a word for special files is true.
[-D FILE] IfFILE exists and is a directory is true.
[-e FILE] IfFILE exists is true.
[-F FILE] IfFile exists and is a normal file is true.
[-G FILE] IfFILE exists and has been setThe Sgid is true.[-H FILE] IfFILE exists and is a symbolic join is true.
[-K FILE] IfTrue if FILE exists and the sticky bit has been set.
[-P FILE] IfFILE exists and is a name pipe(F ifO) is true.
[-R FILE] IfTrue if FILE exists and is readable.
[-S FILE] ifFILE exists and size is not0 is true.
[-T FD] if the file descriptorFD is turned on and pointing to a terminal is true.
[-U FILE] IfFILE exists and is setThe SUID (set user ID) is true.
[-W FILE] IfFILE ifTrue if FILE exists and is writable.
[-X FILE] IfTrue if FILE exists and is executable.
[-O FILE] IfFILE exists and is a valid userThe ID is true.
[-G FILE] IfFILE exists and is valid user group is true.
[-L FILE] IfFILE exists and is a symbolic join is true.
[-N FILE] IfFILE existsand has been mod ifIED since it is last read is true.
[-S FILE] ifFILE exists and is a socket true.
[File1-nt FILE2] IfFILE1 have been changed more recently than FILE2, or ifFILE1 exists and FILE2 does not are true.
[File1-ot FILE2] IfFILE1 ratioFILE2 to be old.OrFILE2 exists andFILE1 is true if it does not exist.
[File1-ef FILE2] IfFILE1 andFILE2 points to the same device and the node number is true.
[-O optionname] IfShell options  "Optionname"   is true.   
[-Z string]  ' string '   is true for a length of zero.   
[-N string] or [string]  "string"   length is not 0   The Non-zero is true.   
[STRING1 = = STRING2]   if 2 strings are the same.   "=" May is used instead of "= =" for strict POSIX compliance is true.   
[STRING1! = STRING2]   If the strings are not equal.  
[STRING1 < STRING2]   if   "STRING1" sorts before " STRING2 "lexicographically in the current locale is true.   
[STRING1 > STRING2]   if   "STRING1" sorts After ' STRING2 ' lexicographically in the current locale is true.  

Shell condition judgment