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Annotation of 42BSD/ucb/ex/expreserve.c, revision 1.1

1.1     ! root        1: /* Copyright (c) 1981 Regents of the University of California */
        !             2: static char *sccsid = "@(#)expreserve.c        7.8     8/14/83";
        !             3: #include <stdio.h>
        !             4: #include <ctype.h>
        !             5: #include <sys/param.h>
        !             6: #include <sys/stat.h>
        !             7: #include <sys/dir.h>
        !             8: #include <pwd.h>
        !             9: #include "uparm.h"
        !            10: 
        !            11: #define TMP    "/tmp"
        !            12: 
        !            13: #ifdef VMUNIX
        !            14: #define        HBLKS   2
        !            15: #else
        !            16: #define HBLKS  1
        !            17: #endif
        !            18: 
        !            19: char xstr[1];                  /* make loader happy */
        !            20: 
        !            21: /*
        !            22:  * Expreserve - preserve a file in usrpath(preserve)
        !            23:  * Bill Joy UCB November 13, 1977
        !            24:  *
        !            25:  * This routine is very naive - it doesn't remove anything from
        !            26:  * usrpath(preserve)... this may mean that we leave
        !            27:  * stuff there... the danger in doing anything with usrpath(preserve)
        !            28:  * is that the clock may be screwed up and we may get confused.
        !            29:  *
        !            30:  * We are called in two ways - first from the editor with no argumentss
        !            31:  * and the standard input open on the temp file. Second with an argument
        !            32:  * to preserve the entire contents of /tmp (root only).
        !            33:  *
        !            34:  * BUG: should do something about preserving Rx... (register contents)
        !            35:  *      temporaries.
        !            36:  */
        !            37: 
        !            38: #ifndef VMUNIX
        !            39: #define        LBLKS   125
        !            40: #else
        !            41: #define        LBLKS   900
        !            42: #endif
        !            43: #define        FNSIZE  128
        !            44: 
        !            45: struct         header {
        !            46:        time_t  Time;                   /* Time temp file last updated */
        !            47:        int     Uid;                    /* This users identity */
        !            48: #ifndef VMUNIX
        !            49:        short   Flines;                 /* Number of lines in file */
        !            50: #else
        !            51:        int     Flines;
        !            52: #endif
        !            53:        char    Savedfile[FNSIZE];      /* The current file name */
        !            54:        short   Blocks[LBLKS];          /* Blocks where line pointers stashed */
        !            55: } H;
        !            56: 
        !            57: #ifdef lint
        !            58: #define        ignore(a)       Ignore(a)
        !            59: #define        ignorl(a)       Ignorl(a)
        !            60: #else
        !            61: #define        ignore(a)       a
        !            62: #define        ignorl(a)       a
        !            63: #endif
        !            64: 
        !            65: struct passwd *getpwuid();
        !            66: off_t  lseek();
        !            67: FILE   *popen();
        !            68: 
        !            69: #define eq(a, b) strcmp(a, b) == 0
        !            70: 
        !            71: main(argc)
        !            72:        int argc;
        !            73: {
        !            74:        register DIR *tf;
        !            75:        struct direct *dirent;
        !            76:        struct stat stbuf;
        !            77: 
        !            78:        /*
        !            79:         * If only one argument, then preserve the standard input.
        !            80:         */
        !            81:        if (argc == 1) {
        !            82:                if (copyout((char *) 0))
        !            83:                        exit(1);
        !            84:                exit(0);
        !            85:        }
        !            86: 
        !            87:        /*
        !            88:         * If not super user, then can only preserve standard input.
        !            89:         */
        !            90:        if (getuid()) {
        !            91:                fprintf(stderr, "NOT super user\n");
        !            92:                exit(1);
        !            93:        }
        !            94: 
        !            95:        /*
        !            96:         * ... else preserve all the stuff in /tmp, removing
        !            97:         * it as we go.
        !            98:         */
        !            99:        if (chdir(TMP) < 0) {
        !           100:                perror(TMP);
        !           101:                exit(1);
        !           102:        }
        !           103: 
        !           104:        tf = opendir(".");
        !           105:        if (tf == NULL) {
        !           106:                perror(TMP);
        !           107:                exit(1);
        !           108:        }
        !           109:        while ((dirent = readdir(tf)) != NULL) {
        !           110:                /* Ex temporaries must begin with Ex. */
        !           111:                if (dirent->d_name[0] != 'E' || dirent->d_name[1] != 'x')
        !           112:                        continue;
        !           113:                if (stat(dirent->d_name, &stbuf))
        !           114:                        continue;
        !           115:                if ((stbuf.st_mode & S_IFMT) != S_IFREG)
        !           116:                        continue;
        !           117:                /*
        !           118:                 * Save the bastard.
        !           119:                 */
        !           120:                ignore(copyout(dirent->d_name));
        !           121:        }
        !           122:        closedir(tf);
        !           123:        exit(0);
        !           124: }
        !           125: 
        !           126: char   pattern[] =     usrpath(preserve/Exaa`XXXXX);
        !           127: 
        !           128: /*
        !           129:  * Copy file name into usrpath(preserve)/...
        !           130:  * If name is (char *) 0, then do the standard input.
        !           131:  * We make some checks on the input to make sure it is
        !           132:  * really an editor temporary, generate a name for the
        !           133:  * file (this is the slowest thing since we must stat
        !           134:  * to find a unique name), and finally copy the file.
        !           135:  */
        !           136: copyout(name)
        !           137:        char *name;
        !           138: {
        !           139:        int i;
        !           140:        static int reenter;
        !           141:        char buf[BUFSIZ];
        !           142: 
        !           143:        /*
        !           144:         * The first time we put in the digits of our
        !           145:         * process number at the end of the pattern.
        !           146:         */
        !           147:        if (reenter == 0) {
        !           148:                mkdigits(pattern);
        !           149:                reenter++;
        !           150:        }
        !           151: 
        !           152:        /*
        !           153:         * If a file name was given, make it the standard
        !           154:         * input if possible.
        !           155:         */
        !           156:        if (name != 0) {
        !           157:                ignore(close(0));
        !           158:                /*
        !           159:                 * Need read/write access for arcane reasons
        !           160:                 * (see below).
        !           161:                 */
        !           162:                if (open(name, 2) < 0)
        !           163:                        return (-1);
        !           164:        }
        !           165: 
        !           166:        /*
        !           167:         * Get the header block.
        !           168:         */
        !           169:        ignorl(lseek(0, 0l, 0));
        !           170:        if (read(0, (char *) &H, sizeof H) != sizeof H) {
        !           171: format:
        !           172:                if (name == 0)
        !           173:                        fprintf(stderr, "Buffer format error\t");
        !           174:                return (-1);
        !           175:        }
        !           176: 
        !           177:        /*
        !           178:         * Consistency checsks so we don't copy out garbage.
        !           179:         */
        !           180:        if (H.Flines < 0) {
        !           181: #ifdef DEBUG
        !           182:                fprintf(stderr, "Negative number of lines\n");
        !           183: #endif
        !           184:                goto format;
        !           185:        }
        !           186:        if (H.Blocks[0] != HBLKS || H.Blocks[1] != HBLKS+1) {
        !           187: #ifdef DEBUG
        !           188:                fprintf(stderr, "Blocks %d %d\n", H.Blocks[0], H.Blocks[1]);
        !           189: #endif
        !           190:                goto format;
        !           191:        }
        !           192:        if (name == 0 && H.Uid != getuid()) {
        !           193: #ifdef DEBUG
        !           194:                fprintf(stderr, "Wrong user-id\n");
        !           195: #endif
        !           196:                goto format;
        !           197:        }
        !           198:        if (lseek(0, 0l, 0)) {
        !           199: #ifdef DEBUG
        !           200:                fprintf(stderr, "Negative number of lines\n");
        !           201: #endif
        !           202:                goto format;
        !           203:        }
        !           204: 
        !           205:        /*
        !           206:         * If no name was assigned to the file, then give it the name
        !           207:         * LOST, by putting this in the header.
        !           208:         */
        !           209:        if (H.Savedfile[0] == 0) {
        !           210:                strcpy(H.Savedfile, "LOST");
        !           211:                ignore(write(0, (char *) &H, sizeof H));
        !           212:                H.Savedfile[0] = 0;
        !           213:                lseek(0, 0l, 0);
        !           214:        }
        !           215: 
        !           216:        /*
        !           217:         * File is good.  Get a name and create a file for the copy.
        !           218:         */
        !           219:        mknext(pattern);
        !           220:        ignore(close(1));
        !           221:        if (creat(pattern, 0600) < 0) {
        !           222:                if (name == 0)
        !           223:                        perror(pattern);
        !           224:                return (1);
        !           225:        }
        !           226: 
        !           227:        /*
        !           228:         * Make the target be owned by the owner of the file.
        !           229:         */
        !           230:        ignore(chown(pattern, H.Uid, 0));
        !           231: 
        !           232:        /*
        !           233:         * Copy the file.
        !           234:         */
        !           235:        for (;;) {
        !           236:                i = read(0, buf, BUFSIZ);
        !           237:                if (i < 0) {
        !           238:                        if (name)
        !           239:                                perror("Buffer read error");
        !           240:                        ignore(unlink(pattern));
        !           241:                        return (-1);
        !           242:                }
        !           243:                if (i == 0) {
        !           244:                        if (name)
        !           245:                                ignore(unlink(name));
        !           246:                        notify(H.Uid, H.Savedfile, (int) name);
        !           247:                        return (0);
        !           248:                }
        !           249:                if (write(1, buf, i) != i) {
        !           250:                        if (name == 0)
        !           251:                                perror(pattern);
        !           252:                        unlink(pattern);
        !           253:                        return (-1);
        !           254:                }
        !           255:        }
        !           256: }
        !           257: 
        !           258: /*
        !           259:  * Blast the last 5 characters of cp to be the process number.
        !           260:  */
        !           261: mkdigits(cp)
        !           262:        char *cp;
        !           263: {
        !           264:        register int i, j;
        !           265: 
        !           266:        for (i = getpid(), j = 5, cp += strlen(cp); j > 0; i /= 10, j--)
        !           267:                *--cp = i % 10 | '0';
        !           268: }
        !           269: 
        !           270: /*
        !           271:  * Make the name in cp be unique by clobbering up to
        !           272:  * three alphabetic characters into a sequence of the form 'aab', 'aac', etc.
        !           273:  * Mktemp gets weird names too quickly to be useful here.
        !           274:  */
        !           275: mknext(cp)
        !           276:        char *cp;
        !           277: {
        !           278:        char *dcp;
        !           279:        struct stat stb;
        !           280: 
        !           281:        dcp = cp + strlen(cp) - 1;
        !           282:        while (isdigit(*dcp))
        !           283:                dcp--;
        !           284: whoops:
        !           285:        if (dcp[0] == 'z') {
        !           286:                dcp[0] = 'a';
        !           287:                if (dcp[-1] == 'z') {
        !           288:                        dcp[-1] = 'a';
        !           289:                        if (dcp[-2] == 'z')
        !           290:                                fprintf(stderr, "Can't find a name\t");
        !           291:                        dcp[-2]++;
        !           292:                } else
        !           293:                        dcp[-1]++;
        !           294:        } else
        !           295:                dcp[0]++;
        !           296:        if (stat(cp, &stb) == 0)
        !           297:                goto whoops;
        !           298: }
        !           299: 
        !           300: /*
        !           301:  * Notify user uid that his file fname has been saved.
        !           302:  */
        !           303: notify(uid, fname, flag)
        !           304:        int uid;
        !           305:        char *fname;
        !           306: {
        !           307:        struct passwd *pp = getpwuid(uid);
        !           308:        register FILE *mf;
        !           309:        char cmd[BUFSIZ];
        !           310: 
        !           311:        if (pp == NULL)
        !           312:                return;
        !           313:        sprintf(cmd, "/bin/mail %s", pp->pw_name);
        !           314:        mf = popen(cmd, "w");
        !           315:        if (mf == NULL)
        !           316:                return;
        !           317:        setbuf(mf, cmd);
        !           318:        if (fname[0] == 0) {
        !           319:                fprintf(mf,
        !           320: "A copy of an editor buffer of yours was saved when %s.\n",
        !           321:                flag ? "the system went down" : "the editor was killed");
        !           322:                fprintf(mf,
        !           323: "No name was associated with this buffer so it has been named \"LOST\".\n");
        !           324:        } else
        !           325:                fprintf(mf,
        !           326: "A copy of an editor buffer of your file \"%s\"\nwas saved when %s.\n", fname,
        !           327:                /*
        !           328:                 * "the editor was killed" is perhaps still not an ideal
        !           329:                 * error message.  Usually, either it was forcably terminated
        !           330:                 * or the phone was hung up, but we don't know which.
        !           331:                 */
        !           332:                flag ? "the system went down" : "the editor was killed");
        !           333:        fprintf(mf,
        !           334: "This buffer can be retrieved using the \"recover\" command of the editor.\n");
        !           335:        fprintf(mf,
        !           336: "An easy way to do this is to give the command \"ex -r %s\".\n",fname);
        !           337:        fprintf(mf,
        !           338: "This works for \"edit\" and \"vi\" also.\n");
        !           339:        pclose(mf);
        !           340: }
        !           341: 
        !           342: /*
        !           343:  *     people making love
        !           344:  *     never exactly the same
        !           345:  *     just like a snowflake 
        !           346:  */
        !           347: 
        !           348: #ifdef lint
        !           349: Ignore(a)
        !           350:        int a;
        !           351: {
        !           352: 
        !           353:        a = a;
        !           354: }
        !           355: 
        !           356: Ignorl(a)
        !           357:        long a;
        !           358: {
        !           359: 
        !           360:        a = a;
        !           361: }
        !           362: #endif

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