1 .TH READCONS 3
2 .SH NAME
3 readcons \- prompt console for input
4 .SH SYNOPSIS
5 .B
6 #include <u.h>
7 .PP
8 .B
9 #include <libc.h>
10 .PP
11 .B
12 char *readcons(char *prompt, char *def, int secret)
13 .SH DESCRIPTION
14 .I Readcons
15 prompts at the console for input.
16 It returns a NUL-terminated buffer containing the input
17 without a final newline.
18 The buffer should be freed (and perhaps cleared first) 
19 when no longer needed.
20 .PP
21 If the user types an empty string (just a newline) and
22 .I def
23 is non-zero, then a copy of 
24 .I def
25 is returned instead of the empty string.
26 .PP
27 If
28 .I secret
29 is non-zero, the input is not echoed to the screen.
30 .SH EXAMPLE
31 A stripped-down version of
32 .I netkey
33 (see
34 .MR passwd (1) ):
35 .IP
36 .EX
37 pass = readcons("password", nil, 1);
38 passtokey(key, pass);
39 memset(pass, 0, strlen(pass));
40 free(pass);
41 for(;;){
42 	chal = readcons("challenge", nil, 0);
43 	sprint(buf, "%d", strtol(chal, 0, 10));
44 	free(chal);
45 	netcrypt(key, buf);
46 	print("response: %s\n", buf);
47 }
48 .EE
49 .SH SOURCE
50 .B \*9/src/lib9/readcons.c