In linux, if the input value of getch () is not displayed, linuxgetch

In linux, if the input value of getch () is not displayed, linuxgetch

In linux, C programs are developed, but the system does not support the conio. h header file. getch () cannot be used to not echo the function. The following example shows how to build a function to achieve non-echo of numeric input.

1 # include <stdio. h> 2 3 # include <termios. h> 4 5 # include <unistd. h> 6 7 # include <errno. h> 8 9 # define ECHOFLAGS (ECHO | ECHOE | ECHOK | ECHONL) 10 11 // The set_disp_mode function is used to control whether the input ECHO function is enabled 12 13 // if option is 0, if this parameter is set to 1, the echo 14 15 int set_disp_mode (int fd, int option) 16 17 {18 19 int err; 20 21 struct termios term is enabled; 22 23 if (tcgetattr (fd, & term) =-1) {24 25 perror ("Cannot get the attribution of the termina L "); 26 27 return 1; 28 29} 30 31 if (option) 32 33 term. c_lflag | = ECHOFLAGS; 34 35 else 36 37 term. c_lflag & = ~ ECHOFLAGS; 38 39 err = tcsetattr (fd, TCSAFLUSH, & term); 40 41 if (err =-1 & err = EINTR) {42 43 perror ("Cannot set the attribution of the terminal"); 44 45 return 1; 46 47} 48 49 return 0; 50 51} 52 53 // function getpasswd is used to obtain the password entered by the user and store it in the specified character array 54 55 int getpasswd (char * passwd, int size) 56 57 {58 59 int c; 60 61 int n = 0; 62 63 64 65 printf ("Please Input password :"); 66 67 68 69 do {70 71 c = getchar (); 72 73 if (c! = '\ N' | c! = '\ R') {74 75 passwd [n ++] = c; 76 77} 78 79} while (c! = '\ N' & c! = '\ R' & n <(size-1); 80 81 passwd [n] =' \ 0'; 82 83 return n; 84 85} 86 87 int main () 88 89 {90 91 char * p, passwd [20], name [20]; 92 93 printf ("Please Input name :"); 94 95 scanf ("% s", name); 96 97 getchar (); // block the carriage return to 98 99 // disable the output echo first, in this way, the entered character information 100 101 set_disp_mode (STDIN_FILENO, 0) is not displayed. 102 103 // call the getpasswd function to obtain the user-Entered password 104 105 getpasswd (passwd, sizeof (passwd); 106 107 p = passwd; 108 109 whi Le (* p! = '\ N') 110 111 p ++; 112 113 * p =' \ 0'; 114 115 printf ("\ nYour name is: % s", name ); 116 117 printf ("\ nYour passwd is: % s \ n", passwd); 118 119 printf ("Press any key continue... \ n "); 120 121 set_disp_mode (STDIN_FILENO, 1); 122 123 getchar (); 124 125 return 0; 126 127 128} 129 130 131 132 133

Running result:

Note: in Linux, when C Programming encounters the problem of entering a password, the password cannot be seen at the time of input. I originally wanted to use getch () but getch () is not supported in Linux-C, and I have not found a function like function. The above example has achieved the expected results.