Category : UNIX Files
Archive   : PC-MAIL2.ZIP
Filename : MAIL.C

/*++
/* NAME
/* mail
/* SUMMARY
/* visual mail-shell
/* PROJECT
/* pc-mail
/* PACKAGE
/* mail
/* SYNOPSIS
/* mail
/* DESCRIPTION
/* mail is an interactive program for reading, receiving
/* and producing electronic mail. Actually, most of the work
/* is done by programs called by the mail program.
/*
/* By default, the program presents the user display of a list of
/* mail messages in the form of one-line summaries. Single-key
/* commands are available to select and manipulate mail messages.
/* Mail messages are created with an editor chosen by the user.
/*
/* The name of the spool directory, printer program and editor
/* are taken from the environment, or assume system-dependent defaults.
/* ENVIRONMENT
/* MAILDIR name of spool directory
/* EDITOR name of program to create mail
/* MAILPRN name of program/file to print with/to
/* MAILCMD command to execute upon termination
/* COMMANDS
/* cico network communications program
/* nmail postprocessor for mail received by cico
/* FILES
/* The mail system maintains various files in a spool directory,
/* as well as a logfile of all network transactions.
/* SEE ALSO
/* path(3) system-dependent path names
/* DIAGNOSTICS
/* Error messages should be self-explanatory.
/* BUGS
/* The user has to explicitly tell the system to contact a remote
/* mail host. This is a limitation of MS-DOS, not of the program.
/* AUTHOR(S)
/* W.Z. Venema
/* Eindhoven University of Technology
/* Department of Mathematics and Computer Science
/* Den Dolech 2, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
/* CREATION DATE
/* Thu Apr 2 21:54:08 GMT+1:00 1987
/* LAST MODIFICATION
/* 90/01/22 13:02:04
/* VERSION/RELEASE
/* 2.1
/*--*/

#include
#include
#include "defs.h"
#include "path.h"
#include "status.h"
#include "mail.h"
#include "window.h"

public char *progname = "mail"; /* for diagnostics */

/* forward declarations */

hidden int checkfiles();

/* for now, don't even try to look at command args */

public main(argc, argv)
int argc;
char **argv;
{
register int stat;

/*
* Initializations: get screen control and function-key codes (wininit).
* check if the limit on the number of open files is ok (checkfiles), get
* the values from environment variables (pathinit), set the terminal
* driver to the desired mode (kbdinit), check for partally processed new
* mail with the nmail program. Also make sure that our file permissions
* are safe (umask).
*/

if (!isatty(fileno(stdin))) {
perror("mail: standard input");
exit(1);
}
umask(022); /* avoid problems */
wininit(); /* do termcap stuff */
clrscreen(); /* clear screen */
(stat = checkfiles()) /* get max nbr of open files */
||(stat = pathinit()) /* get spool, printer, editor */
||(stat = invokelp(NMAIL, (char *) 0)); /* just in case there's mail */
kbdinit(); /* set to tty RAW, NOECHO */
if (stat) {
errdisp(stat); /* we have a problem */
} else {
init(); /* start the machine */
}

/* finalizations */

kbdrest(); /* restore tty driver */
clrscreen(); /* clear screen */
fflush(stdout);
if (stat == 0)
onexit(mailcmd); /* do exit command */
exit(stat);
/* NOTREACHED */
}

/* checkfiles - make sure we can open as many files as we want */

hidden int checkfiles()
{
register int i;
int fds[MINFILES];
register int stat;

for (i = 0; i < MINFILES; i++) /* try to open many files */
if ((fds[i] = open(NULLDEV, 0)) < 0)
break;

stat = (i < MINFILES ? E_FILENO : 0); /* did we fail? */

while (--i >= 0) /* release files */
close(fds[i]);
return (stat);
}

/* onexit - exec another command */

int onexit(command)
char *command;
{
if (command && *command)
return (system(command));
}