Use the tcgetattr and tcsetattr functions to solve the password echo problem.

Use the tcgetattr and tcsetattr Functions

There is another way to solve the Password Input echo problem without using the curses library. The program p6.4.c achieves the same purpose by using the tcgetattr function and the tcsetattr function. The Code is as follows:

# Include <stdio. h> # Include <termios. h> # Include <unistd. h> # Include <errno. h> # Define echoflags (echo | echoe | echok | echonl) // The set_disp_mode function is used to control whether the input echo function is enabled. // If option is 0, the echo is disabled. If option is 1, the echo is enabled. Int set_disp_mode (int fd, int option) { Int err; Struct termios term; If (tcgetattr (FD, & term) =-1 ){ Perror ("cannot get the attribution of the terminal "); Return 1; } If (option) Term. c_lflag | = echoflags; Else Term. c_lflag & = ~ Echoflags; Err = tcsetattr (FD, tcsaflush, & term ); If (ERR =-1 & err = eintr ){ Perror ("cannot set the attribution of the terminal "); Return 1; } Return 0; } // The getpasswd function is used to obtain the password entered by the user and store it in the specified character array. Int getpasswd (char * passwd, int size) { Int C; Int n = 0; Printf ("Please input password :"); Do { C = getchar (); If (C! = '/N' | C! = '/R '){ Passwd [n ++] = C; } } While (C! = '/N' & C! = '/R' & n <(size-1 )); Passwd [N] = '/0 '; Return N; } Int main () { Char passwd [20]; // Close the output echo first, so that the input character information is not displayed when the password is entered. Set_disp_mode (stdin_fileno, 0 ); // Call the getpasswd function to obtain the password entered by the user Getpasswd (passwd, sizeof (passwd )); Printf ("/Nyour passwd is: % s/n", passwd ); Printf ("press any key continue.../N "); Set_disp_mode (stdin_fileno, 1 ); Getchar (); Return 0; }

Use GCC to compile the p6.4.c code and obtain an executable program named p6.4. Run the program and get the following output:

[program@localhost charter6]$ gcc -o p6.4 p6.4.c [program@localhost charter6]$ ./p6.4 Please Input password: Your passwd is:afdfasf Press any key continue ... [program@localhost charter6]$