put in check for a particular botch which seems to be happening for no reason

[unix-history] / usr / src / usr.bin / mail / ing.local.c

#

/*
* Mail -- a mail program
*
* Ingres 11/70.  Unix version 6.0
*
* Local routines that are installation dependent.
* All fiddlers please note:  if you make careful note of
* what you change here, I will incorporate your changes and
* you won't have to remake them each release.
*/

static char *SccsId = "@(#)ing.local.c  2.1 %G%";

#include "rcv.h"
#include        <errno.h>

/*
* Locate the user's mailbox file (ie, the place where new, unread
* mail is queued).  At Ingres, it's in /usr/spool/mail/loginname.
*/

findmail()
{
       register char *cp;

       cp = copy("/usr/spool/mail/", mailname);
       copy(myname, cp);
}

/*
* Get rid of the queued mail.
*/

demail()
{
       if (unlink(mailname) >= 0)
               return;
       close(creat(mailname, 0666));
       alter(mailname);
}

/*
* Get an environment variable.  At present, we only support
* "SHELL" and "HOME".  This routine makes use of the getpw
* routine in the neighboring getname.c stuff.
*/

char *
getenv(name)
       char name[];
{
       char pwline[LINESIZE];
       static char val[30];
       register char *cp, *dp;
       register int cc;

       if (equal(name, "SHELL"))
               cc = 6;
       else if (equal(name, "HOME"))
               cc = 5;
       else
               return(NOSTR);
       if (getpwnam(myname, pwline) < 0)
               return(NOSTR);
       for (cp = pwline; *cp && cc > 0;)
               if (*cp++ == ':')
                       cc--;
       dp = cp;
       while (*cp != ':' && *cp != '\0' && *cp != '\n')
               cp++;
       *cp = '\0';
       if (*dp == '\0')
               return(NOSTR);
       copy(dp, val);
       return(val);
}

/*
* Discover user name.  On Ingres, user names are rarely 1-1 with uids,
* so we look for this guy in the utmp file first, then try finding
* him in the passwd file on basis of uid if that fails.
*/

struct utmp {
       char    u_name[8];              /* User login name. */
       char    u_tty;                  /* typewriter character */
       char    u_cfill;                /* Unused for now. */
       long    u_time;                 /* Login time */
       short   u_wfill;                /* Unused also */
};

username(uid, namebuf)
       char namebuf[];
{
       struct utmp ubuf;
       register char *cp;
       register int tty;
       register FILE *fwho;

       tty = ttyn(0);
       if (tty == 'x')
               goto useuid;
       
       /*
        * Dammit, I really do have to search the utmp file!
        */

       if ((fwho = fopen("/etc/utmp", "r")) == NULL)
               goto useuid;
       while (fread(&ubuf, 1, sizeof ubuf, fwho) > 0)
               if (ubuf.u_tty == tty) {
                       strncpy(namebuf, ubuf.u_name, 8);
                       namebuf[8] = 0;
                       cp = index(namebuf, ' ');
                       if (cp != NOSTR)
                               *cp = 0;
                       return(0);
               }
       fclose(fwho);

useuid:
       return(getname(uid, namebuf));
}

/*
* Unix routine to do an "fopen" on file descriptor
* The mode has to be repeated because you can't query its
* status
*/

FILE *
fdopen(fd, mode)
register char *mode;
{
       extern int errno;
       register FILE *iop;
       extern FILE *_lastbuf;

       for (iop = _iob; iop->_flag&(_IOREAD|_IOWRT); iop++)
               if (iop >= _lastbuf)
                       return(NULL);
       iop->_cnt = 0;
       iop->_file = fd;
       if (*mode != 'r') {
               iop->_flag |= _IOWRT;
               if (*mode == 'a')
                       lseek(fd, 0L, 2);
       } else
               iop->_flag |= _IOREAD;
       return(iop);
}

/*
* Copy s2 to s1, truncating or null-padding to always copy n bytes
* return s1
*/

char *
strncpy(s1, s2, n)
register char *s1, *s2;
{
       register i;
       register char *os1;

       os1 = s1;
       for (i = 0; i < n; i++)
               if ((*s1++ = *s2++) == '\0') {
                       while (++i < n)
                               *s1++ = '\0';
                       return(os1);
               }
       return(os1);
}