ref: 333468d668d5079bcf7651d4e25d688b6e7a833e
dir: /sys/src/libauthsrv/readcons.c/
#include <u.h> #include <libc.h> /* * prompt for a string with a possible default response */ char* readcons(char *prompt, char *def, int raw) { int fdin, fdout, ctl, n; char *s, *p; s = p = nil; fdout = ctl = -1; if((fdin = open("/dev/cons", OREAD)) < 0) goto Out; if((fdout = open("/dev/cons", OWRITE)) < 0) goto Out; if(raw){ if((ctl = open("/dev/consctl", OWRITE)) < 0) goto Out; write(ctl, "rawon", 5); } if(def != nil) fprint(fdout, "%s[%s]: ", prompt, def); else fprint(fdout, "%s: ", prompt); for(;;){ n = p - s; if((n % 32) == 0){ if((p = realloc(s, n+32)) == nil) break; s = p, p += n; } if(read(fdin, p, 1) <= 0 || *p == 0x7f) break; if(*p == '\n' || *p == '\r'){ if(p == s && def != nil){ free(s); s = strdup(def); } else *p = 0; if(raw) write(fdout, "\n", 1); goto Out; } else if(*p == '\b') { while(p > s && (p[-1] & 0xc0) == 0x80) *p-- = 0; if(p > s) *p-- = 0; } else if(*p == 0x15) { /* ^U: line kill */ if(def != nil) fprint(fdout, "\n%s[%s]: ", prompt, def); else fprint(fdout, "\n%s: ", prompt); while(p > s) *p-- = 0; } else if(*p >= ' ') p++; } free(s); s = nil; if(raw) write(fdout, "\n", 1); Out: if(ctl >= 0){ write(ctl, "rawoff", 6); close(ctl); } if(fdin >= 0) close(fdin); if(fdout >= 0) close(fdout); return s; }