Special characters in Linux

Special Character Processing for Shell in Linux: in non-regular expressions, matching is not greedy: * match any string in the file name, including null string? Match any single character in the file name [a-z] to match any single character in [! A] Match! Any subsequent characters> rewrite with redirection, new if not,> append the content <standard input 2> & 1, and output the error together. solve the Problem of 1> a.txt 2> a.txt conflict 1> & 2 output the normal output together with the error. solve the Problem of 1> a.txt 2> a.txt conflict 0 <m.txt uses the file m as the standard input 1> m.txt redirects the standard output to the file m <&-Disable the standard input 2> &- disable Error output, 2>/dev/null $ () indicates execution () the statement <1.txt> 2.txt uses the 1.txt file as the standard input and uses the 2.txt file as the standard output. <filename uses the f I l e n a m e file as the standard input. <delimiter reads data from the standard input, until the d e l I m I t e r separator echo aa> temp.txt & let the command be executed in the background, that is, the echo aa> temp.txt 2> & 1 & background is not displayed and the standard Output errors and errors are all redirected to temp.txt nohup command & the background executes the exit account and continues ls [! 0-9] * display the ls ??? N * starts with a, followed by n