/* elvprsv.c */
/* Author:
* Steve Kirkendall
* 14407 SW Teal Blvd. #C
* Beaverton, OR 97005
* kirkenda@cs.pdx.edu
*/
/* This file contains the portable sources for the "elvprsv" program.
* "Elvprsv" is run by Elvis when Elvis is about to die. It is also
* run when the computer boots up. It is not intended to be run directly
* by the user, ever.
*
* Basically, this program does the following four things:
* - It extracts the text from the temporary file, and places the text in
* a file in the /usr/preserve directory.
* - It adds a line to the /usr/preserve/Index file, describing the file
* that it just preserved.
* - It removes the temporary file.
* - It sends mail to the owner of the file, saying that the file was
* preserved, and how it can be recovered.
*
* The /usr/preserve/Index file is a log file that contains one line for each
* file that has ever been preserved. Each line of this file describes one
* preserved file. The first word on the line is the name of the file that
* contains the preserved text. The second word is the full pathname of the
* file that was being edited; for anonymous buffers, this is the directory
* name plus "/foo".
*
* If elvprsv's first argument (after the command name) starts with a hyphen,
* then the characters after the hyphen are used as a description of when
* the editor went away. This is optional.
*
* The remaining arguments are all the names of temporary files that are
* to be preserved. For example, on a UNIX system, the /etc/rc file might
* invoke it this way:
*
* elvprsv "-the system went down" /tmp/elv_*.*
*
* This file contains only the portable parts of the preserve program.
* It must #include a system-specific file. The system-specific file is
* expected to define the following functions:
*
* char *ownername(char *filename) - returns name of person who owns file
*
* void mail(char *user, char *name, char *when)
* - tell user that file was preserved
*/
#include <stdio.h>
#include "config.h"
#include "vi.h"
/* We include ctype.c here (instead of including just ctype.h and linking
* with ctype.o) because on some systems ctype.o will have been compiled in
* "large model" and the elvprsv program is to be compiled in "small model"
* You can't mix models. By including ctype.c here, we can avoid linking
* with ctype.o.
*/
#include "ctype.c"
void preserve P_((char *, char *));
void main P_((int, char **));
#if AMIGA
BLK tmpblk;
# include "amiwild.c"
# include "amiprsv.c"
#endif
#if OSK
# undef sprintf
#endif
#if ANY_UNIX || OSK
# include "prsvunix.c"
#endif
#if MSDOS || TOS
# include "prsvdos.c"
# define WILDCARD_NO_MAIN
# include "wildcard.c"
#endif
BLK buf;
BLK hdr;
BLK name;
int rewrite_now; /* boolean: should we send text directly to orig file? */
/* This function preserves a single file, and announces its success/failure
* via an e-mail message.
*/
void preserve(tname, when)
char *tname; /* name of a temp file to be preserved */
char *when; /* description of when the editor died */
{
int infd; /* fd used for reading from the temp file */
FILE *outfp; /* fp used for writing to the recovery file */
FILE *index; /* fp used for appending to index file */
char outname[100]; /* the name of the recovery file */
char *user; /* name of the owner of the temp file */
#if AMIGA
char *prsvdir;
#endif
int i;
/* open the temp file */
infd = open(tname, O_RDONLY|O_BINARY);
if (infd < 0)
{
/* if we can't open the file, then we should assume that
* the filename contains wildcard characters that weren't
* expanded... and also assume that they weren't expanded
* because there are no files that need to be preserved.
* THEREFORE... we should silently ignore it.
* (Or loudly ignore it if the user was using -R)
*/
if (rewrite_now)
{
perror(tname);
}
return;
}
/* read the header and name from the file */
if (read(infd, hdr.c, BLKSIZE) != BLKSIZE
|| read(infd, name.c, BLKSIZE) != BLKSIZE)
{
/* something wrong with the file - sorry */
fprintf(stderr, "%s: truncated header blocks\n", tname);
close(infd);
return;
}
/* If the filename block contains an empty string, then Elvis was
* only keeping the temp file around because it contained some text
* that was needed for a named cut buffer. The user doesn't care
* about that kind of temp file, so we should silently delete it.
*/
if (name.c[0] == '\0' && name.c[1] == '\177')
{
close(infd);
unlink(tname);
return;
}
/* If there are no text blocks in the file, then we must've never
* really started editing. Discard the file.
*/
if (hdr.n[1] == 0)
{
close(infd);
unlink(tname);
return;
}
if (rewrite_now)
{
/* we don't need to open the index file */
index = (FILE *)0;
/* make sure we can read every block! */
for (i = 1; i < MAXBLKS && hdr.n[i]; i++)
{
lseek(infd, (long)hdr.n[i] * (long)BLKSIZE, 0);
if (read(infd, buf.c, BLKSIZE) != BLKSIZE
|| buf.c[0] == '\0')
{
/* messed up header */
fprintf(stderr, "%s: unrecoverable -- header trashed\n", name.c);
close(infd);
return;
}
}
/* open the user's file for writing */
outfp = fopen(name.c, "w");
if (!outfp)
{
perror(name.c);
close(infd);
return;
}
}
else
{
/* open/create the index file */
index = fopen(PRSVINDEX, "a");
if (!index)
{
perror(PRSVINDEX);
exit(2);
}
/* should be at the end of the file already, but MAKE SURE */
fseek(index, 0L, 2);
/* create the recovery file in the PRESVDIR directory */
#if AMIGA
prsvdir = &PRSVDIR[strlen(PRSVDIR) - 1];
if (*prsvdir == '/' || *prsvdir == ':')
{
sprintf(outname, "%sp%ld", PRSVDIR, ftell(index));
}
else
#endif
sprintf(outname, "%s%cp%ld", PRSVDIR, SLASH, ftell(index));
outfp = fopen(outname, "w");
if (!outfp)
{
perror(outname);
close(infd);
fclose(index);
return;
}
}
/* write the text of the file out to the recovery file */
for (i = 1; i < MAXBLKS && hdr.n[i]; i++)
{
lseek(infd, (long)hdr.n[i] * (long)BLKSIZE, 0);
if (read(infd, buf.c, BLKSIZE) != BLKSIZE
|| buf.c[0] == '\0')
{
/* messed up header */
fprintf(stderr, "%s: unrecoverable -- header trashed\n", name.c);
fclose(outfp);
close(infd);
if (index)
{
fclose(index);
}
unlink(outname);
return;
}
fputs(buf.c, outfp);
}
/* add a line to the index file */
if (index)
{
fprintf(index, "%s %s\n", outname, name.c);
}
/* close everything */
close(infd);
fclose(outfp);
if (index)
{
fclose(index);
}
/* Are we doing this due to something more frightening than just
* a ":preserve" command?
*/
if (*when)
{
/* send a mail message */
mail(ownername(tname), name.c, when);
/* remove the temp file -- the editor has died already */
unlink(tname);
}
}
void main(argc, argv)
int argc;
char **argv;
{
int i;
char *when = "the editor went away";
#if MSDOS || TOS
/* expand any wildcards in the command line */
_ct_init("");
argv = wildexpand(&argc, argv);
#endif
/* do we have a "-c", "-R", or "-when elvis died" argument? */
i = 1;
if (argc >= i + 1 && !strcmp(argv[i], "-R"))
{
rewrite_now = 1;
when = "";
i++;
#if ANY_UNIX
setuid(geteuid());
#endif
}
#if OSK
else
{
setuid(0);
}
#endif
if (argc >= i + 1 && argv[i][0] == '-')
{
when = argv[i] + 1;
i++;
}
/* preserve everything we're supposed to */
while (i < argc)
{
preserve(argv[i], when);
i++;
}
}