Judgment in the shell

-e file If file exists, true-d file if file is a directory, true-f file If file is regular, true-l file if file is a symbolic link, true-r file if file is readable, true-W file True-X If file is writable, or true-s file if files are executable or true-h if the file is a soft link, true-z files if the file or directory does not exist, it is true in front of the add! It means reverse, such as! -H filefile1-nt file2 True if the file1 is newer than file2. File1-ot File2 If File1 is older than file2, it is true. -eq equals equal to ==-ne not equal to!=-gt greater than equal to >-ge greater than equals to >=-lt less equal to <-le less than equals to <=

Judgment in the shell