If parameter in shell script

[-A file] true if the file exists. <Br/> [-B file] If the file exists and is a special block file, it is true. <Br/> [-C file] If the file exists and is a special character file, it is true. <Br/> [-D file] If the file exists and is a directory, it is true. <Br/> [-e file] If the file exists, it is true. <Br/> [-F file] If the file exists and is a common file, it is true. <Br/> [-G file] If the file exists and the sgid has been set, it is true. <Br/> [-H file] If the file exists and is a symbolic connection, it is true. <Br/> [-K file] true if the file exists and the stick bits have been set. <Br/> [-P file] If the file exists and is a name pipe (f If O), it is true. <Br/> [-r file] true if the file exists and is readable. <Br/> [-s file] If the file exists and the size is not 0, it is true. <Br/> [-t fd] It is true if the file descriptor FD is opened and points to a terminal. <Br/> [-u file] true if the file exists and SUID (Set User ID) is set. <Br/> [-W file] If the file exists and is writable, it is true. <Br/> [-X file] true if the file exists and is executable. <Br/> [-o file] true if the file exists and belongs to a valid user ID. <Br/> [-G file] true if the file exists and belongs to a valid user group. <Br/> [-l file] If the file exists and is a symbolic connection, it is true. <Br/> [-N file] If the file exists and has been mod, it is true if IED since it was last read. <Br/> [-s file] If the file exists and is a socket, it is true. <Br/> [file1-nt file2] If file1 has been changed more recently than file2, or if file1file2 does not is true. <Br/> exists and [file1-ot file2] True if file1 is older than file2, or if file2 exists and file1 does not exist. <Br/> [file1-Ef file2] True if file1 and file2 point to the same device and node number. <Br/> [-O optionname] true if the shell option "optionname" is enabled. <Br/> [-Z string] "string" is true if its length is zero. <Br/> If the length of [-N string] or [String] "string" is non-zero, it is true. <Br/> [string1 = string2] If the two strings are the same. "=" May be used instead of "=" for strict POSIX compliance is true. <Br/> [string1! = String2] true if the strings are not equal. <Br/> [string1 <string2] True if "string1" sorts before "string2" lexicographically in the current locale. <Br/> [string1> string2] True if "string1" sorts after "string2" lexicographically in the current locale.