/* 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 #include "config.h" #include "vi.h" #if AMIGA BLK tmpblk; #error AMIGA here DEBUG # 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: trucated 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 (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) { /* 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(1); } /* 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) { /* 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); } } 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 */ argv = wildexpand(&argc, argv); #endif /* do we have a "when" 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++; } }