2.9BSD/usr/src/ucb/chfn.c
#ifndef lint
static char *sccsid = "@(#)chfn.c 4.3 (Berkeley) 5/18/83";
#endif lint
/*
* changefinger - change finger entries
*/
#include <whoami.h>
#include <stdio.h>
#include <signal.h>
#include <pwd.h>
#include <ctype.h>
#include <sys/types.h>
struct default_values {
char *name;
char *office_num;
char *office_phone;
char *home_phone;
};
char passwd[] = "/etc/passwd";
char temp[] = "/etc/ptmp";
struct passwd *pwd;
struct passwd *getpwent(), *getpwnam(), *getpwuid();
int endpwent();
char *crypt();
char *getpass();
char buf[BUFSIZ];
main(argc, argv)
int argc;
char *argv[];
{
int user_uid;
unsigned num_bytes;
int fi, fo;
char replacement[4*BUFSIZ];
FILE *tf;
if (argc > 2) {
printf("Usage: changefinger [user]\n");
exit(1);
}
/*
* Error check to make sure the user (foolishly) typed their own name.
*/
user_uid = getuid();
if ((argc == 2) && (user_uid != 0)) {
pwd = getpwnam(argv[1]);
if (pwd == NULL) {
printf("%s%s%s%s%s%s%s%s",
"There is no account for ", argv[1],
" on this machine.\n",
"You probably mispelled your login name;\n",
"only root is allowed to change another",
" person's finger entry.\n",
"Note: you do not need to type your login",
" name as an argument.\n");
exit(1);
}
if (pwd->pw_uid != user_uid) {
printf("%s%s",
"You are not allowed to change another",
" person's finger entry.\n");
exit(1);
}
}
/*
* If root is changing a finger entry, then find the uid that
* corresponds to the user's login name.
*/
if ((argc == 2) && (user_uid == 0)) {
pwd = getpwnam(argv[1]);
if (pwd == NULL) {
printf("There is no account for %s on this machine\n",
pwd->pw_name);
exit(1);
}
user_uid = pwd->pw_uid;
}
if (argc == 1) {
pwd = getpwuid(user_uid);
if (pwd == NULL) {
fprintf(stderr, "No passwd file entry!?\n");
exit(1);
}
}
/*
* Collect name, room number, school phone, and home phone.
*/
get_info(pwd->pw_gecos, replacement);
/*
* Update the entry in the password file.
*/
while (access(temp, 0) >= 0) {
printf("Password file busy -- waiting for it to be free.\n");
sleep(10);
}
(void) signal(SIGHUP, SIG_IGN);
(void) signal(SIGINT, SIG_IGN);
(void) signal(SIGQUIT, SIG_IGN);
#ifdef MENLO_JCL
(void) signal(SIGTSTP, SIG_IGN);
#endif
/*
* Race condition -- the locking mechinism is not my idea (ns)
*/
if (access(temp, 0) >= 0) {
printf("It's not your day! Password file is busy again.\n");
printf("Try again later.\n");
exit(1);
}
if ((tf=fopen(temp,"w")) == NULL) {
printf("Cannot create temporary file\n");
exit(1);
}
/*
* There is another race condition here: if the passwd file
* has changed since the error checking at the beginning of the program,
* then user_uid may not be in the file. Of course, the uid might have
* been changed, but this is not supposed to happen.
*/
if (getpwuid(user_uid) == NULL) {
printf("%s%d%s\n", "Passwd file has changed. Uid ", user_uid,
" is no longer in the file!?");
goto out;
}
/*
* copy passwd to temp, replacing matching line
* with new finger entry (gecos field).
*/
while ((pwd=getpwent()) != NULL) {
if (pwd->pw_uid == user_uid) {
pwd->pw_gecos = replacement;
}
fprintf(tf,"%s:%s:%d:%d:%s:%s:%s\n",
pwd->pw_name,
pwd->pw_passwd,
pwd->pw_uid,
pwd->pw_gid,
pwd->pw_gecos,
pwd->pw_dir,
pwd->pw_shell);
}
(void) endpwent();
(void) fclose(tf);
/*
* Copy temp back to password file.
*/
if((fi=open(temp,0)) < 0) {
printf("Temp file disappeared!\n");
goto out;
}
if((fo=creat(passwd, 0644)) < 0) {
printf("Cannot recreat passwd file.\n");
goto out;
}
while((num_bytes=read(fi,buf,sizeof(buf))) > 0)
(void) write(fo,buf,num_bytes);
out:
(void) unlink(temp);
}
/*
* Get name, room number, school phone, and home phone.
*/
get_info(gecos_field, answer)
char *gecos_field;
char *answer;
{
char *strcpy(), *strcat();
char in_str[BUFSIZ];
struct default_values *defaults, *get_defaults();
answer[0] = '\0';
defaults = get_defaults(gecos_field);
printf("Default values are printed inside of of '[]'.\n");
printf("To accept the default, type <return>.\n");
printf("To have a blank entry, type the word 'none'.\n");
/*
* Get name.
*/
do {
printf("\nName [%s]: ", defaults->name);
(void) fgets(in_str, BUFSIZ, stdin);
if (special_case(in_str, defaults->name))
break;
} while (ill_input(in_str));
(void) strcpy(answer, in_str);
/*
* Get room number.
*/
do {
printf("Room number (Exs: 597E or 197C) [%s]: ",
defaults->office_num);
(void) fgets(in_str, BUFSIZ, stdin);
if (special_case(in_str, defaults->office_num))
break;
} while (ill_input(in_str) || ill_building(in_str));
(void) strcat(strcat(answer, ","), in_str);
/*
* Get office phone number.
* Remove hyphens and 642, x2, or 2 prefixes if present.
*/
do {
printf("Office Phone (Ex: 1632) [%s]: ",
defaults->office_phone);
(void) fgets(in_str, BUFSIZ, stdin);
if (special_case(in_str, defaults->office_phone))
break;
remove_hyphens(in_str);
if ((strlen(in_str) == 8) && (strncmp(in_str, "642", 3) == 0))
(void) strcpy(in_str, in_str+3);
if ((strlen(in_str) == 7) && (strncmp(in_str, "x2", 2) == 0))
(void) strcpy(in_str, in_str+2);
if ((strlen(in_str) == 6) && (in_str[0] == '2'))
(void) strcpy(in_str, in_str+1);
} while (ill_input(in_str) || not_all_digits(in_str)
|| wrong_length(in_str, 4));
(void) strcat(strcat(answer, ","), in_str);
/*
* Get home phone number.
* Remove hyphens if present.
*/
do {
printf("Home Phone (Ex: 9875432) [%s]: ", defaults->home_phone);
(void) fgets(in_str, BUFSIZ, stdin);
if (special_case(in_str, defaults->home_phone))
break;
remove_hyphens(in_str);
} while (ill_input(in_str) || not_all_digits(in_str));
(void) strcat(strcat(answer, ","), in_str);
}
/*
* Prints an error message if a ':' or a newline is found in the string.
* A message is also printed if the input string is too long.
* The password file uses :'s as seperators, and are not allowed in the "gcos"
* field. Newlines serve as delimiters between users in the password file,
* and so, those too, are checked for. (I don't think that it is possible to
* type them in, but better safe than sorry)
*
* Returns '1' if a colon or newline is found or the input line is too long.
*/
ill_input(input_str)
char *input_str;
{
char *index();
char *ptr;
int error_flag = 0;
int length = strlen(input_str);
if (index(input_str, ':')) {
printf("':' is not allowed.\n");
error_flag = 1;
}
if (input_str[length-1] != '\n') {
/* the newline and the '\0' eat up two characters */
printf("Maximum number of characters allowed is %d\n",
BUFSIZ-2);
/* flush the rest of the input line */
while (getchar() != '\n')
/* void */;
error_flag = 1;
}
/*
* Delete newline by shortening string by 1.
*/
input_str[length-1] = '\0';
/*
* Don't allow control characters, etc in input string.
*/
for (ptr=input_str; *ptr != '\0'; ptr++) {
if ((int) *ptr < 040) {
printf("Control characters are not allowed.\n");
error_flag = 1;
break;
}
}
return(error_flag);
}
/*
* Removes '-'s from the input string.
*/
remove_hyphens(str)
char *str;
{
char *hyphen, *index(), *strcpy();
while ((hyphen=index(str, '-')) != NULL) {
(void) strcpy(hyphen, hyphen+1);
}
}
/*
* Checks to see if 'str' contains only digits (0-9). If not, then
* an error message is printed and '1' is returned.
*/
not_all_digits(str)
char *str;
{
char *ptr;
for (ptr=str; *ptr != '\0'; ++ptr) {
if (!isdigit(*ptr)) {
printf("Phone numbers can only contain digits.\n");
return(1);
}
}
return(0);
}
/*
* Returns 1 when the length of the input string is not zero or equal to n.
* Prints an error message in this case.
*/
wrong_length(str, n)
char *str;
int n;
{
if ((strlen(str) != 0) && (strlen(str) != n)) {
printf("The phone number should be %d digits long.\n", n);
return(1);
}
return(0);
}
/*
* Make sure that building is 'E' or 'C'.
* Error correction is done if building is 'e', 'c', "evans", or "cory".
* Correction changes "str".
* The finger program determines the building by looking at the last
* character. Currently, finger only allows that character to be 'E' or 'C'.
*
* Returns 1 if incorrect room format.
*
* Note: this function assumes that the newline has been removed from str.
*/
ill_building(str)
char *str;
{
int length = strlen(str);
char *last_ch, *ptr;
/*
* Zero length strings are acceptable input.
*/
if (length == 0)
return(0);
/*
* Delete "vans" and "ory".
*/
if (strncmp(str+length-4, "vans", 4) == 0) {
length -= 4;
str[length] = '\0';
}
if (strncmp(str+length-3, "ory", 3) == 0) {
length -= 3;
str[length] = '\0';
}
last_ch = str+length-1;
/*
* Now change e to E or c to C.
*/
if (*last_ch == 'e')
*last_ch = 'E';
if (*last_ch == 'c')
*last_ch = 'C';
/*
* Delete any spaces before the E or C.
*/
for (ptr=last_ch-1; ptr>str; ptr--) {
if (*ptr != ' ')
break;
}
(void) strcpy(ptr+1, last_ch);
/*
* Make sure building is evans or cory.
*/
if ((*last_ch != 'E') && (*last_ch != 'C')) {
printf("%s%s%s",
"The finger program requires that your",
" office be in Cory or Evans.\n",
"Enter this as (for example) 597E or 197C.\n");
return(1);
}
return(0);
}
/* get_defaults picks apart "str" and returns a structure points.
* "str" contains up to 4 fields separated by commas.
* Any field that is missing is set to blank.
*/
struct default_values
*get_defaults(str)
char *str;
{
struct default_values *answer;
char *malloc(), *index();
answer = (struct default_values *)
malloc((unsigned)sizeof(struct default_values));
if (answer == (struct default_values *) NULL) {
fprintf(stderr,
"\nUnable to allocate storage in get_defaults!\n");
exit(1);
}
/*
* Values if no corresponding string in "str".
*/
answer->name = str;
answer->office_num = "";
answer->office_phone = "";
answer->home_phone = "";
str = index(answer->name, ',');
if (str == 0)
return(answer);
*str = '\0';
answer->office_num = str + 1;
str = index(answer->office_num, ',');
if (str == 0)
return(answer);
*str = '\0';
answer->office_phone = str + 1;
str = index(answer->office_phone, ',');
if (str == 0)
return(answer);
*str = '\0';
answer->home_phone = str + 1;
return(answer);
}
/*
* special_case returns true when either the default is accepted
* (str = '\n'), or when 'none' is typed. 'none' is accepted in
* either upper or lower case (or any combination). 'str' is modified
* in these two cases.
*/
int special_case(str,default_str)
char *str;
char *default_str;
{
static char word[] = "none\n";
char *ptr, *wordptr;
/*
* If the default is accepted, then change the old string do the
* default string.
*/
if (*str == '\n') {
(void) strcpy(str, default_str);
return(1);
}
/*
* Check to see if str is 'none'. (It is questionable if case
* insensitivity is worth the hair).
*/
wordptr = word-1;
for (ptr=str; *ptr != '\0'; ++ptr) {
++wordptr;
if (*wordptr == '\0') /* then words are different sizes */
return(0);
if (*ptr == *wordptr)
continue;
if (isupper(*ptr) && (tolower(*ptr) == *wordptr))
continue;
/*
* At this point we have a mismatch, so we return
*/
return(0);
}
/*
* Make sure that words are the same length.
*/
if (*(wordptr+1) != '\0')
return(0);
/*
* Change 'str' to be the null string
*/
*str = '\0';
return(1);
}