Annotation of 42BSD/ucb/chfn.c, revision 1.1.1.1

1.1       root        1: #ifndef lint
                      2: static char *sccsid = "@(#)chfn.c      4.6 (Berkeley) 7/10/83";
                      3: #endif lint
                      4: 
                      5: /*
                      6:  *      changefinger - change finger entries
                      7:  */
                      8: #include <stdio.h>
                      9: #include <signal.h>
                     10: #include <pwd.h>
                     11: #include <sys/time.h>
                     12: #include <sys/resource.h>
                     13: #include <sys/file.h>
                     14: #include <ctype.h>
                     15: 
                     16: struct default_values {
                     17:        char *name;
                     18:        char *office_num;
                     19:        char *office_phone;
                     20:        char *home_phone;
                     21: };
                     22: 
                     23: char   passwd[] = "/etc/passwd";
                     24: char   temp[]   = "/etc/ptmp";
                     25: struct passwd *pwd;
                     26: struct passwd *getpwent(), *getpwnam(), *getpwuid();
                     27: int    endpwent();
                     28: char   *crypt();
                     29: char   *getpass();
                     30: 
                     31: main(argc, argv)
                     32:        int argc;
                     33:        char *argv[];
                     34: {
                     35:        int user_uid;
                     36:        char replacement[4*BUFSIZ];
                     37:        int fd;
                     38:        FILE *tf;
                     39: 
                     40:        if (argc > 2) {
                     41:                printf("Usage: changefinger [user]\n");
                     42:                exit(1);
                     43:        }
                     44:        /*
                     45:         * Error check to make sure the user (foolishly) typed their own name.
                     46:         */
                     47:        user_uid = getuid();
                     48:        if ((argc == 2) && (user_uid != 0)) {
                     49:                pwd = getpwnam(argv[1]);
                     50:                if (pwd == NULL) {
                     51:                        printf("%s%s%s%s%s%s%s%s",
                     52:                                "There is no account for ", argv[1],
                     53:                                " on this machine.\n", 
                     54:                                "You probably mispelled your login name;\n",
                     55:                                "only root is allowed to change another",
                     56:                                " person's finger entry.\n",
                     57:                                "Note:  you do not need to type your login",
                     58:                                " name as an argument.\n");
                     59:                        exit(1);
                     60:                }
                     61:                if (pwd->pw_uid != user_uid) {
                     62:                        printf("%s%s",
                     63:                                "You are not allowed to change another",
                     64:                                " person's finger entry.\n");
                     65:                        exit(1);
                     66:                }
                     67:        }
                     68:        /*
                     69:         * If root is changing a finger entry, then find the uid that
                     70:         * corresponds to the user's login name.
                     71:         */
                     72:        if ((argc == 2) && (user_uid == 0)) {
                     73:                pwd = getpwnam(argv[1]);
                     74:                if (pwd == NULL) {
                     75:                        printf("There is no account for %s on this machine\n", 
                     76:                                pwd->pw_name);
                     77:                        exit(1);
                     78:                }
                     79:                user_uid = pwd->pw_uid;
                     80:        }
                     81:        if (argc == 1) {
                     82:                pwd = getpwuid(user_uid);
                     83:                if (pwd == NULL) {
                     84:                        fprintf(stderr, "No passwd file entry!?\n");
                     85:                        exit(1);
                     86:                }
                     87:        }
                     88:        /*
                     89:         * Collect name, room number, school phone, and home phone.
                     90:         */
                     91:        get_info(pwd->pw_gecos, replacement);
                     92: 
                     93:        (void) signal(SIGHUP, SIG_IGN);
                     94:        (void) signal(SIGINT, SIG_IGN);
                     95:        (void) signal(SIGQUIT, SIG_IGN);
                     96:        (void) signal(SIGTSTP, SIG_IGN);
                     97:        (void) umask(0);
                     98:        if ((fd = open(temp, O_CREAT|O_EXCL|O_RDWR, 0644)) < 0) {
                     99:                printf("Temporary file busy -- try again\n");
                    100:                exit(1);
                    101:        }
                    102:        if ((tf = fdopen(fd, "w")) == NULL) {
                    103:                printf("Absurd fdopen failure - seek help\n");
                    104:                goto out;
                    105:        }
                    106:        unlimit(RLIMIT_CPU);
                    107:        unlimit(RLIMIT_FSIZE);
                    108:        /*
                    109:         * Copy passwd to temp, replacing matching lines
                    110:         * with new gecos field.
                    111:         */
                    112:        while ((pwd = getpwent()) != NULL) {
                    113:                if (pwd->pw_uid == user_uid)
                    114:                        pwd->pw_gecos = replacement;
                    115:                fprintf(tf,"%s:%s:%d:%d:%s:%s:%s\n",
                    116:                        pwd->pw_name,
                    117:                        pwd->pw_passwd,
                    118:                        pwd->pw_uid,
                    119:                        pwd->pw_gid,
                    120:                        pwd->pw_gecos,
                    121:                        pwd->pw_dir,
                    122:                        pwd->pw_shell);
                    123:        }
                    124:        (void) endpwent();
                    125:        if (rename(temp, passwd) < 0) {
                    126:                fprintf(stderr, "chfn: "); perror("rename");
                    127:   out:
                    128:                (void) unlink(temp);
                    129:                exit(1);
                    130:        }
                    131:        (void) fclose(tf);
                    132:        exit(0);
                    133: }
                    134: 
                    135: unlimit(lim)
                    136: {
                    137:        struct rlimit rlim;
                    138: 
                    139:        rlim.rlim_cur = rlim.rlim_max = RLIM_INFINITY;
                    140:        (void) setrlimit(lim, &rlim);
                    141: }
                    142: 
                    143: /*
                    144:  * Get name, room number, school phone, and home phone.
                    145:  */
                    146: get_info(gecos_field, answer)
                    147:        char *gecos_field;
                    148:        char *answer;
                    149: {
                    150:        char *strcpy(), *strcat();
                    151:        char in_str[BUFSIZ];
                    152:        struct default_values *defaults, *get_defaults();
                    153: 
                    154:        answer[0] = '\0';
                    155:        defaults = get_defaults(gecos_field);
                    156:        printf("Default values are printed inside of of '[]'.\n");
                    157:        printf("To accept the default, type <return>.\n");
                    158:        printf("To have a blank entry, type the word 'none'.\n");
                    159:        /*
                    160:         * Get name.
                    161:         */
                    162:        do {
                    163:                printf("\nName [%s]: ", defaults->name);
                    164:                (void) fgets(in_str, BUFSIZ, stdin);
                    165:                if (special_case(in_str, defaults->name)) 
                    166:                        break;
                    167:        } while (illegal_input(in_str));
                    168:        (void) strcpy(answer, in_str);
                    169:        /*
                    170:         * Get room number.
                    171:         */
                    172:        do {
                    173:                printf("Room number (Exs: 597E or 197C) [%s]: ",
                    174:                        defaults->office_num);
                    175:                (void) fgets(in_str, BUFSIZ, stdin);
                    176:                if (special_case(in_str, defaults->office_num))
                    177:                        break;
                    178:        } while (illegal_input(in_str) || illegal_building(in_str));
                    179:        (void) strcat(strcat(answer, ","), in_str);
                    180:        /*
                    181:         * Get office phone number.
                    182:         * Remove hyphens and 642, x2, or 2 prefixes if present.
                    183:         */
                    184:        do {
                    185:                printf("Office Phone (Ex: 1632) [%s]: ",
                    186:                        defaults->office_phone);
                    187:                (void) fgets(in_str, BUFSIZ, stdin);
                    188:                if (special_case(in_str, defaults->office_phone))
                    189:                        break;
                    190:                remove_hyphens(in_str);
                    191:                if ((strlen(in_str) == 8) && (strcmpn(in_str, "642", 3) == 0))
                    192:                        (void) strcpy(in_str, in_str+3);
                    193:                if ((strlen(in_str) == 7) && (strcmpn(in_str, "x2", 2) == 0))
                    194:                        (void) strcpy(in_str, in_str+2);
                    195:                if ((strlen(in_str) == 6) && (in_str[0] == '2'))
                    196:                        (void) strcpy(in_str, in_str+1);
                    197:        } while (illegal_input(in_str) || not_all_digits(in_str)
                    198:                 || wrong_length(in_str, 4));
                    199:        (void) strcat(strcat(answer, ","), in_str);
                    200:        /*
                    201:         * Get home phone number.
                    202:         * Remove hyphens if present.
                    203:         */
                    204:        do {
                    205:                printf("Home Phone (Ex: 9875432) [%s]: ", defaults->home_phone);
                    206:                (void) fgets(in_str, BUFSIZ, stdin);
                    207:                if (special_case(in_str, defaults->home_phone))
                    208:                        break;
                    209:                remove_hyphens(in_str);
                    210:        } while (illegal_input(in_str) || not_all_digits(in_str));
                    211:        (void) strcat(strcat(answer, ","), in_str);
                    212: }
                    213: 
                    214: /*
                    215:  * Prints an error message if a ':' or a newline is found in the string.
                    216:  * A message is also printed if the input string is too long.
                    217:  * The password file uses :'s as seperators, and are not allowed in the "gcos"
                    218:  * field.  Newlines serve as delimiters between users in the password file,
                    219:  * and so, those too, are checked for.  (I don't think that it is possible to
                    220:  * type them in, but better safe than sorry)
                    221:  *
                    222:  * Returns '1' if a colon or newline is found or the input line is too long.
                    223:  */
                    224: illegal_input(input_str)
                    225:        char *input_str;
                    226: {
                    227:        char *index();
                    228:        char *ptr;
                    229:        int error_flag = 0;
                    230:        int length = strlen(input_str);
                    231: 
                    232:        if (index(input_str, ':')) {
                    233:                printf("':' is not allowed.\n");
                    234:                error_flag = 1;
                    235:        }
                    236:        if (input_str[length-1] != '\n') {
                    237:                /* the newline and the '\0' eat up two characters */
                    238:                printf("Maximum number of characters allowed is %d\n",
                    239:                        BUFSIZ-2);
                    240:                /* flush the rest of the input line */
                    241:                while (getchar() != '\n')
                    242:                        /* void */;
                    243:                error_flag = 1;
                    244:        }
                    245:        /*
                    246:         * Delete newline by shortening string by 1.
                    247:         */
                    248:        input_str[length-1] = '\0';
                    249:        /*
                    250:         * Don't allow control characters, etc in input string.
                    251:         */
                    252:        for (ptr=input_str; *ptr != '\0'; ptr++) {
                    253:                if ((int) *ptr < 040) {
                    254:                        printf("Control characters are not allowed.\n");
                    255:                        error_flag = 1;
                    256:                        break;
                    257:                }
                    258:        }
                    259:        return(error_flag);
                    260: }
                    261: 
                    262: /*
                    263:  * Removes '-'s from the input string.
                    264:  */
                    265: remove_hyphens(str)
                    266:        char *str;
                    267: {
                    268:        char *hyphen, *index(), *strcpy();
                    269: 
                    270:        while ((hyphen=index(str, '-')) != NULL) {
                    271:                (void) strcpy(hyphen, hyphen+1);
                    272:        }
                    273: }
                    274: 
                    275: /*
                    276:  *  Checks to see if 'str' contains only digits (0-9).  If not, then
                    277:  *  an error message is printed and '1' is returned.
                    278:  */
                    279: not_all_digits(str)
                    280:        char *str;
                    281: {
                    282:        char *ptr;
                    283: 
                    284:        for (ptr=str; *ptr != '\0'; ++ptr) {
                    285:                if (!isdigit(*ptr)) {
                    286:                        printf("Phone numbers can only contain digits.\n");
                    287:                        return(1);
                    288:                }
                    289:        }
                    290:        return(0);
                    291: }
                    292: 
                    293: /*
                    294:  * Returns 1 when the length of the input string is not zero or equal to n.
                    295:  * Prints an error message in this case.
                    296:  */
                    297: wrong_length(str, n)
                    298:        char *str;
                    299:        int n;
                    300: {
                    301: 
                    302:        if ((strlen(str) != 0) && (strlen(str) != n)) {
                    303:                printf("The phone number should be %d digits long.\n", n);
                    304:                return(1);
                    305:        }
                    306:        return(0);
                    307: }
                    308: 
                    309: /*
                    310:  * Make sure that building is 'E' or 'C'.
                    311:  * Error correction is done if building is 'e', 'c', "evans", or "cory".
                    312:  * Correction changes "str".
                    313:  * The finger program determines the building by looking at the last
                    314:  * character.  Currently, finger only allows that character to be 'E' or 'C'.
                    315:  *
                    316:  * Returns 1 if incorrect room format.
                    317:  * 
                    318:  * Note: this function assumes that the newline has been removed from str.
                    319:  */
                    320: illegal_building(str)
                    321:        char *str;
                    322: {
                    323:        int length = strlen(str);
                    324:        char *last_ch, *ptr;
                    325: 
                    326:        /*
                    327:         * Zero length strings are acceptable input.
                    328:         */
                    329:        if (length == 0)
                    330:                return(0);
                    331:        /*
                    332:         * Delete "vans" and "ory".
                    333:         */
                    334:        if (strcmpn(str+length-4, "vans", 4) == 0) {
                    335:                length -= 4;
                    336:                str[length] = '\0';
                    337:        }
                    338:        if (strcmpn(str+length-3, "ory", 3) == 0) {
                    339:                length -= 3;
                    340:                str[length] = '\0';
                    341:        }
                    342:        last_ch = str+length-1;
                    343:        /*
                    344:         * Now change e to E or c to C.
                    345:         */
                    346:        if (*last_ch == 'e')
                    347:                *last_ch = 'E';
                    348:        if (*last_ch == 'c')
                    349:                *last_ch = 'C';
                    350:        /*
                    351:         * Delete any spaces before the E or C.
                    352:         */
                    353:        for (ptr=last_ch-1; ptr>str; ptr--) {
                    354:                if (*ptr != ' ')
                    355:                        break;
                    356:        }
                    357:        (void) strcpy(ptr+1, last_ch);
                    358:        /*
                    359:         * Make sure building is evans or cory.
                    360:         */
                    361:        if ((*last_ch != 'E') && (*last_ch != 'C')) {
                    362:                printf("%s%s%s",
                    363:                        "The finger program requires that your",
                    364:                        " office be in Cory or Evans.\n",
                    365:                        "Enter this as (for example) 597E or 197C.\n");
                    366:                return(1);
                    367:        }
                    368:        return(0);
                    369: }
                    370: 
                    371: /* get_defaults picks apart "str" and returns a structure points.
                    372:  * "str" contains up to 4 fields separated by commas.
                    373:  * Any field that is missing is set to blank.
                    374:  */
                    375: struct default_values 
                    376: *get_defaults(str)
                    377:        char *str;
                    378: {
                    379:        struct default_values *answer;
                    380:        char *malloc(), *index();
                    381: 
                    382:        answer = (struct default_values *)
                    383:                malloc((unsigned)sizeof(struct default_values));
                    384:        if (answer == (struct default_values *) NULL) {
                    385:                fprintf(stderr,
                    386:                        "\nUnable to allocate storage in get_defaults!\n");
                    387:                exit(1);
                    388:        }
                    389:        /*
                    390:         * Values if no corresponding string in "str".
                    391:         */
                    392:        answer->name = str;
                    393:        answer->office_num = "";
                    394:        answer->office_phone = "";
                    395:        answer->home_phone = "";
                    396:        str = index(answer->name, ',');
                    397:        if (str == 0) 
                    398:                return(answer);
                    399:        *str = '\0';
                    400:        answer->office_num = str + 1;
                    401:        str = index(answer->office_num, ',');
                    402:        if (str == 0) 
                    403:                return(answer);
                    404:        *str = '\0';
                    405:        answer->office_phone = str + 1;
                    406:        str = index(answer->office_phone, ',');
                    407:        if (str == 0) 
                    408:                return(answer);
                    409:        *str = '\0';
                    410:        answer->home_phone = str + 1;
                    411:        return(answer);
                    412: }
                    413: 
                    414: /*
                    415:  *  special_case returns true when either the default is accepted
                    416:  *  (str = '\n'), or when 'none' is typed.  'none' is accepted in
                    417:  *  either upper or lower case (or any combination).  'str' is modified
                    418:  *  in these two cases.
                    419:  */
                    420: int special_case(str,default_str)
                    421:        char *str;
                    422:        char *default_str;
                    423: {
                    424:        static char word[] = "none\n";
                    425:        char *ptr, *wordptr;
                    426: 
                    427:        /*
                    428:         *  If the default is accepted, then change the old string do the 
                    429:         *  default string.
                    430:         */
                    431:        if (*str == '\n') {
                    432:                (void) strcpy(str, default_str);
                    433:                return(1);
                    434:        }
                    435:        /*
                    436:         *  Check to see if str is 'none'.  (It is questionable if case
                    437:         *  insensitivity is worth the hair).
                    438:         */
                    439:        wordptr = word-1;
                    440:        for (ptr=str; *ptr != '\0'; ++ptr) {
                    441:                ++wordptr;
                    442:                if (*wordptr == '\0')   /* then words are different sizes */
                    443:                        return(0);
                    444:                if (*ptr == *wordptr)
                    445:                        continue;
                    446:                if (isupper(*ptr) && (tolower(*ptr) == *wordptr))
                    447:                        continue;
                    448:                /*
                    449:                 * At this point we have a mismatch, so we return
                    450:                 */
                    451:                return(0);
                    452:        }
                    453:        /*
                    454:         * Make sure that words are the same length.
                    455:         */
                    456:        if (*(wordptr+1) != '\0')
                    457:                return(0);
                    458:        /*
                    459:         * Change 'str' to be the null string
                    460:         */
                    461:        *str = '\0';
                    462:        return(1);
                    463: }

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