Linux judgment statement

Linux judgment statement detection option meaning-r file or directory this (valid) user or group is readable-w file or directory for this (valid) users or groups are writable-x files or directories. This (valid) user or group is executable-o files or directories from the current (valid) all your-R files or directories. This user (real user) or the group is a readable-W file or directory. This user or group is writable-X files or directories. This user or group is executable-O files or directories owned by this user- e file or directory name-z file exists, the file size is 0 (the directory is always false)-s or the directory exists. The size is greater than 0 (the value is the file size, in bytes) -f is normal text-d is directory-l is symbolic link-S is socket-p is pipeline (Entry is a named pipe (a "fifo ")) -B is a block-special file (such as a disk attached)-c is a character-special file (such as an I/O device) -u setuid File or directory-g setgid File or directory-k File or directory has the sticky bit set-t File handle is TTY (system function isatty () returned result; this test cannot be used for file names.-T files are somewhat like "text" files-B files are somewhat like "binary" files-M modification time (unit: Day) -A access time (unit: Day)-C index node modification time (unit: Day)