1 static char *sccsid ="@(#)biff.c 4.1 (Berkeley) 10/18/80"; 2 /* 3 * biff 4 */ 5 6 #include <sys/types.h> 7 #include <stat.h> 8 #include <stdio.h> 9 10 char *ttyname(); 11 12 main(argc, argv) 13 int argc; 14 char **argv; 15 { 16 char *cp = ttyname(2); 17 struct stat stb; 18 19 argc--, argv++; 20 if (cp == 0) 21 fprintf(stderr, "Where are you?\n"), exit(1); 22 if (stat(cp, &stb) < 0) 23 perror(cp), exit(1); 24 if (argc == 0) { 25 printf("is %s\n", stb.st_mode&0100 ? "y" : "n"); 26 exit((stb.st_mode&0100) ? 0 : 1); 27 } 28 switch (argv[0][0]) { 29 30 case 'y': 31 if (chmod(cp, stb.st_mode|0100) < 0) 32 perror(cp); 33 break; 34 35 case 'n': 36 if (chmod(cp, stb.st_mode&~0100) < 0) 37 perror(cp); 38 break; 39 40 default: 41 fprintf(stderr, "usage: biff [y] [n]\n"); 42 } 43 exit((stb.st_mode&0100) ? 0 : 1); 44 } 45