Research V7 development

[unix-history] / usr / src / cmd / mail.c

#include <stdio.h>
#include <pwd.h>
#include <utmp.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <setjmp.h>
#include <whoami.h>

/*copylet flags */
       /*remote mail, add rmtmsg */
#define REMOTE  1
       /* zap header and trailing empty line */
#define ZAP     3
#define ORDINARY 2
#define FORWARD 4
#define LSIZE   256
#define MAXLET  300     /* maximum number of letters */
#define MAILMODE (~0644)                /* mode of created mail */

char    line[LSIZE];
char    resp[LSIZE];
struct let {
       long    adr;
       char    change;
} let[MAXLET];
int     nlet    = 0;
char    lfil[50];
long    iop, time();
char    lettmp[] = "/tmp/maXXXXX";
char    maildir[] = "/usr/spool/mail/";
char    mailfile[] = "/usr/spool/mail/xxxxxxxxxxxxxxxxxxxxxxx";
char    dead[] = "dead.letter";
char    *thissys = sysname;
char    forwmsg[] = " forwarded\n";
char    *curlock;
int     lockerror;
FILE    *tmpf;
FILE    *malf;
char    *my_name;
char    *getlogin();
struct  passwd  *getpwuid();
int     error;
int     locked;
int     changed;
int     forward;
char    from[] = "From ";
long    ftell();
int     delete();
char    *ctime();
int     flgf;
int     flgp;
int     delflg = 1;
jmp_buf sjbuf;

main(argc, argv)
char **argv;
{
       register i;
       char sobuf[BUFSIZ];

       setbuf(stdout, sobuf);
       mktemp(lettmp);
       unlink(lettmp);
       my_name = getlogin();
       if (my_name == NULL) {
               struct passwd *pwent;
               pwent = getpwuid(getuid());
               if (pwent==NULL)
                       my_name = "???";
               else
                       my_name = pwent->pw_name;
       }
       if(setjmp(sjbuf)) done();
       for (i=0; i<20; i++)
               setsig(i, delete);
       tmpf = fopen(lettmp, "w");
       if (tmpf == NULL) {
               fprintf(stderr, "mail: cannot open %s for writing\n", lettmp);
               done();
       }
       if (argv[0][0] != 'r' &&        /* no favors for rmail*/
          (argc == 1 || argv[1][0] == '-'))
               printmail(argc, argv);
       else
               sendmail(argc, argv);
       done();
}

setsig(i, f)
int i;
int (*f)();
{
       if(signal(i, SIG_IGN)!=SIG_IGN)
               signal(i, f);
}

printmail(argc, argv)
char **argv;
{
       int flg, i, j, print;
       char *p, *getarg();

       setuid(getuid());
       cat(mailfile, maildir, my_name);
       for (; argc>1; argv++, argc--) {
               if (argv[1][0]=='-') {
                       if (argv[1][1]=='q')
                               delflg = 0;
                       else if (argv[1][1]=='p') {
                               flgp++;
                               delflg = 0;
                       } else if (argv[1][1]=='f') {
                               if (argc>=3) {
                                       strcpy(mailfile, argv[2]);
                                       argv++;
                                       argc--;
                               }
                       } else if (argv[1][1]=='r') {
                               forward = 1;
                       } else {
                               fprintf(stderr, "mail: unknown option %c\n", argv[1][1]);
                               done();
                       }
               } else
                       break;
       }
       malf = fopen(mailfile, "r");
       if (malf == NULL) {
               fprintf(stdout, "No mail.\n");
               return;
       }
       lock(mailfile);
       copymt(malf, tmpf);
       fclose(malf);
       fclose(tmpf);
       unlock();
       tmpf = fopen(lettmp, "r");

       changed = 0;
       print = 1;
       for (i = 0; i < nlet; ) {
               j = forward ? i : nlet - i - 1;
               if(setjmp(sjbuf)) {
                       print=0;
               } else {
                       if (print)
                               copylet(j, stdout, ORDINARY);
                       print = 1;
               }
               if (flgp) {
                       i++;
                       continue;
               }
               setjmp(sjbuf);
               fprintf(stdout, "? ");
               fflush(stdout);
               if (fgets(resp, LSIZE, stdin) == NULL)
                       break;
               switch (resp[0]) {

               default:
                       fprintf(stderr, "usage\n");
               case '?':
                       print = 0;
                       fprintf(stderr, "q\tquit\n");
                       fprintf(stderr, "x\texit without changing mail\n");
                       fprintf(stderr, "p\tprint\n");
                       fprintf(stderr, "s[file]\tsave (default mbox)\n");
                       fprintf(stderr, "w[file]\tsame without header\n");
                       fprintf(stderr, "-\tprint previous\n");
                       fprintf(stderr, "d\tdelete\n");
                       fprintf(stderr, "+\tnext (no delete)\n");
                       fprintf(stderr, "m user\tmail to user\n");
                       fprintf(stderr, "! cmd\texecute cmd\n");
                       break;

               case '+':
               case 'n':
               case '\n':
                       i++;
                       break;
               case 'x':
                       changed = 0;
               case 'q':
                       goto donep;
               case 'p':
                       break;
               case '^':
               case '-':
                       if (--i < 0)
                               i = 0;
                       break;
               case 'y':
               case 'w':
               case 's':
                       flg = 0;
                       if (resp[1] != '\n' && resp[1] != ' ') {
                               printf("illegal\n");
                               flg++;
                               print = 0;
                               continue;
                       }
                       if (resp[1] == '\n' || resp[1] == '\0')
                               cat(resp+1, "mbox", "");
                       for (p = resp+1; (p = getarg(lfil, p)) != NULL; ) {
                               malf = fopen(lfil, "a");
                               if (malf == NULL) {
                                       fprintf(stdout, "mail: cannot append to %s\n", lfil);
                                       flg++;
                                       continue;
                               }
                               copylet(j, malf, resp[0]=='w'? ZAP: ORDINARY);
                               fclose(malf);
                       }
                       if (flg)
                               print = 0;
                       else {
                               let[j].change = 'd';
                               changed++;
                               i++;
                       }
                       break;
               case 'm':
                       flg = 0;
                       if (resp[1] == '\n' || resp[1] == '\0') {
                               i++;
                               continue;
                       }
                       if (resp[1] != ' ') {
                               printf("invalid command\n");
                               flg++;
                               print = 0;
                               continue;
                       }
                       for (p = resp+1; (p = getarg(lfil, p)) != NULL; )
                               if (!sendrmt(j, lfil))  /* couldn't send it */
                                       flg++;
                       if (flg)
                               print = 0;
                       else {
                               let[j].change = 'd';
                               changed++;
                               i++;
                       }
                       break;
               case '!':
                       system(resp+1);
                       printf("!\n");
                       print = 0;
                       break;
               case 'd':
                       let[j].change = 'd';
                       changed++;
                       i++;
                       if (resp[1] == 'q')
                               goto donep;
                       break;
               }
       }
  donep:
       if (changed)
               copyback();
}

copyback()      /* copy temp or whatever back to /usr/spool/mail */
{
       register i, n, c;
       int new = 0;
       struct stat stbuf;

       signal(SIGINT, SIG_IGN);
       signal(SIGHUP, SIG_IGN);
       signal(SIGQUIT, SIG_IGN);
       lock(mailfile);
       stat(mailfile, &stbuf);
       if (stbuf.st_size != let[nlet].adr) {   /* new mail has arrived */
               malf = fopen(mailfile, "r");
               if (malf == NULL) {
                       fprintf(stdout, "mail: can't re-read %s\n", mailfile);
                       done();
               }
               fseek(malf, let[nlet].adr, 0);
               fclose(tmpf);
               tmpf = fopen(lettmp, "a");
               fseek(tmpf, let[nlet].adr, 0);
               while ((c = fgetc(malf)) != EOF)
                       fputc(c, tmpf);
               fclose(malf);
               fclose(tmpf);
               tmpf = fopen(lettmp, "r");
               let[++nlet].adr = stbuf.st_size;
               new = 1;
       }
       malf = fopen(mailfile, "w");
       if (malf == NULL) {
               fprintf(stderr, "mail: can't rewrite %s\n", lfil);
               done();
       }
       n = 0;
       for (i = 0; i < nlet; i++)
               if (let[i].change != 'd') {
                       copylet(i, malf, ORDINARY);
                       n++;
               }
       fclose(malf);
       if (new)
               fprintf(stdout, "new mail arrived\n");
       unlock();
}

copymt(f1, f2)  /* copy mail (f1) to temp (f2) */
FILE *f1, *f2;
{
       long nextadr;

       nlet = nextadr = 0;
       let[0].adr = 0;
       while (fgets(line, LSIZE, f1) != NULL) {
               if (isfrom(line))
                       let[nlet++].adr = nextadr;
               nextadr += strlen(line);
               fputs(line, f2);
       }
       let[nlet].adr = nextadr;        /* last plus 1 */
}

copylet(n, f, type) FILE *f;
{       int ch, k;
       fseek(tmpf, let[n].adr, 0);
       k = let[n+1].adr - let[n].adr;
       while(k-- > 1 && (ch=fgetc(tmpf))!='\n')
               if(type!=ZAP) fputc(ch,f);
       if(type==REMOTE)
               fprintf(f, " remote from %s\n", thissys);
       else if (type==FORWARD)
               fprintf(f, forwmsg);
       else if(type==ORDINARY)
               fputc(ch,f);
       while(k-->1)
               fputc(ch=fgetc(tmpf), f);
       if(type!=ZAP || ch!= '\n')
               fputc(fgetc(tmpf), f);
}

isfrom(lp)
register char *lp;
{
       register char *p;

       for (p = from; *p; )
               if (*lp++ != *p++)
                       return(0);
       return(1);
}

sendmail(argc, argv)
char **argv;
{

       time(&iop);
       fprintf(tmpf, "%s%s %s", from, my_name, ctime(&iop));
       iop = ftell(tmpf);
       flgf = 1;
       while (fgets(line, LSIZE, stdin) != NULL) {
               if (line[0] == '.' && line[1] == '\n')
                       break;
               if (isfrom(line))
                       fputs(">", tmpf);
               fputs(line, tmpf);
               flgf = 0;
       }
       fputs("\n", tmpf);
       nlet = 1;
       let[0].adr = 0;
       let[1].adr = ftell(tmpf);
       fclose(tmpf);
       if (flgf)
               return;
       tmpf = fopen(lettmp, "r");
       if (tmpf == NULL) {
               fprintf(stderr, "mail: cannot reopen %s for reading\n", lettmp);
               return;
       }
       while (--argc > 0)
               if (!send(0, *++argv))  /* couldn't send to him */
                       error++;
       if (error) {
               setuid(getuid());
               malf = fopen(dead, "w");
               if (malf == NULL) {
                       fprintf(stdout, "mail: cannot open %s\n", dead);
                       fclose(tmpf);
                       return;
               }
               copylet(0, malf, ZAP);
               fclose(malf);
               fprintf(stdout, "Mail saved in %s\n", dead);
       }
       fclose(tmpf);
}

sendrmt(n, name)
char *name;
{
       FILE *rmf, *popen();
       register char *p;
       char rsys[64], cmd[64];
       register local, pid;
       int sts;

       local = 0;
       if (*name=='!')
               name++;
       for(p=rsys; *name!='!'; *p++ = *name++)
               if (*name=='\0') {
                       local++;
                       break;
               }
       *p = '\0';
       if ((!local && *name=='\0') || (local && *rsys=='\0')) {
               fprintf(stdout, "null name\n");
               return(0);
       }
       if ((pid = fork()) == -1) {
               fprintf(stderr, "mail: can't create proc for remote\n");
               return(0);
       }
       if (pid) {
               while (wait(&sts) != pid) {
                       if (wait(&sts)==-1)
                               return(0);
               }
               return(!sts);
       }
       setuid(getuid());
       if (local)
               sprintf(cmd, "mail %s", rsys);
       else {
               if (index(name+1, '!'))
                       sprintf(cmd, "uux - %s!rmail \\(%s\\)", rsys, name+1);
               else
                       sprintf(cmd, "uux - %s!rmail %s", rsys, name+1);
       }
       if ((rmf=popen(cmd, "w")) == NULL)
               exit(1);
       copylet(n, rmf, local? FORWARD: REMOTE);
       pclose(rmf);
       exit(0);
}

send(n, name)   /* send letter n to name */
int n;
char *name;
{
       char file[50];
       register char *p;
       register mask;
       struct passwd *pw, *getpwnam();

       for(p=name; *p!='!' &&*p!='\0'; p++)
               ;
       if (*p == '!')
               return(sendrmt(n, name));
       if ((pw = getpwnam(name)) == NULL) {
               fprintf(stdout, "mail: can't send to %s\n", name);
               return(0);
       }
       cat(file, maildir, name);
       mask = umask(MAILMODE);
       malf = fopen(file, "a");
       umask(mask);
       if (malf == NULL) {
               fprintf(stdout, "mail: cannot append to %s\n", file);
               return(0);
       }
       lock(file);
       chown(file, pw->pw_uid, pw->pw_gid);
       copylet(n, malf, ORDINARY);
       fclose(malf);
       unlock();
       return(1);
}

delete(i)
{
       setsig(i, delete);
       fprintf(stderr, "\n");
       if(delflg)
               longjmp(sjbuf, 1);
       done();
}

done()
{
       if(!lockerror)
               unlock();
       unlink(lettmp);
       exit(error+lockerror);
}

lock(file)
char *file;
{
       struct stat stbuf;

       if (locked || flgf)
               return;
       if (stat(file, &stbuf)<0)
               return;
       if (stbuf.st_mode&01) {         /* user x bit is the lock */
               if (stbuf.st_ctime+60 >= time((long *)0)) {
                       fprintf(stderr, "%s busy; try again in a minute\n", file);
                       lockerror++;
                       done();
               }
       }
       locked = stbuf.st_mode & ~01;
       curlock = file;
       chmod(file, stbuf.st_mode|01);
}

unlock()
{
       if (locked)
               chmod(curlock, locked);
       locked = 0;
}

cat(to, from1, from2)
char *to, *from1, *from2;
{
       int i, j;

       j = 0;
       for (i=0; from1[i]; i++)
               to[j++] = from1[i];
       for (i=0; from2[i]; i++)
               to[j++] = from2[i];
       to[j] = 0;
}

char *getarg(s, p)      /* copy p... into s, update p */
register char *s, *p;
{
       while (*p == ' ' || *p == '\t')
               p++;
       if (*p == '\n' || *p == '\0')
               return(NULL);
       while (*p != ' ' && *p != '\t' && *p != '\n' && *p != '\0')
               *s++ = *p++;
       *s = '\0';
       return(p);
}