Annotation of 40BSD/cmd/ex/expreserve.c, revision 1.1.1.1

1.1       root        1: /* Copyright (c) 1980 Regents of the University of California */
                      2: static char *sccsid = "@(#)expreserve.c        6.1 10/18/80";
                      3: #include <stdio.h>
                      4: #include <ctype.h>
                      5: #include <sys/types.h>
                      6: #include <sys/stat.h>
                      7: #include <sys/dir.h>
                      8: #include <pwd.h>
                      9: #include "local/uparm.h"
                     10: 
                     11: #ifdef VMUNIX
                     12: #define        HBLKS   2
                     13: #else
                     14: #define        HBLKS   1
                     15: #endif
                     16: 
                     17: /*
                     18:  * Expreserve - preserve a file in usrpath(preserve)
                     19:  * Bill Joy UCB November 13, 1977
                     20:  *
                     21:  * This routine is very naive - it doesn't remove anything from
                     22:  * usrpath(preserve)... this may mean that we will be unable to preserve
                     23:  * stuff there... the danger in doing anything with usrpath(preserve)
                     24:  * is that the clock may be screwed up and we may get confused.
                     25:  *
                     26:  * We are called in two ways - first from the editor with no argumentss
                     27:  * and the standard input open on the temp file. Second with an argument
                     28:  * to preserve the entire contents of /tmp (root only).
                     29:  *
                     30:  * BUG: should do something about preserving Rx... (register contents)
                     31:  *      temporaries.
                     32:  */
                     33: 
                     34: #ifndef VMUNIX
                     35: #define        LBLKS   125
                     36: #else
                     37: #define        LBLKS   900
                     38: #endif
                     39: #define        FNSIZE  128
                     40: 
                     41: struct         header {
                     42:        time_t  Time;                   /* Time temp file last updated */
                     43:        short   Uid;                    /* This users identity */
                     44: #ifndef VMUNIX
                     45:        short   Flines;                 /* Number of lines in file */
                     46: #else
                     47:        int     Flines;
                     48: #endif
                     49:        char    Savedfile[FNSIZE];      /* The current file name */
                     50:        short   Blocks[LBLKS];          /* Blocks where line pointers stashed */
                     51: } H;
                     52: 
                     53: #ifdef lint
                     54: #define        ignore(a)       Ignore(a)
                     55: #define        ignorl(a)       Ignorl(a)
                     56: #else
                     57: #define        ignore(a)       a
                     58: #define        ignorl(a)       a
                     59: #endif
                     60: 
                     61: struct passwd *getpwuid();
                     62: off_t  lseek();
                     63: FILE   *popen();
                     64: 
                     65: #define eq(a, b) strcmp(a, b) == 0
                     66: 
                     67: main(argc)
                     68:        int argc;
                     69: {
                     70:        register FILE *tf;
                     71:        struct direct dirent;
                     72:        struct stat stbuf;
                     73: 
                     74:        /*
                     75:         * If only one argument, then preserve the standard input.
                     76:         */
                     77:        if (argc == 1) {
                     78:                if (copyout((char *) 0))
                     79:                        exit(1);
                     80:                exit(0);
                     81:        }
                     82: 
                     83:        /*
                     84:         * If not super user, then can only preserve standard input.
                     85:         */
                     86:        if (getuid()) {
                     87:                fprintf(stderr, "NOT super user\n");
                     88:                exit(1);
                     89:        }
                     90: 
                     91:        /*
                     92:         * ... else preserve all the stuff in /tmp, removing
                     93:         * it as we go.
                     94:         */
                     95:        if (chdir("/tmp") < 0) {
                     96:                perror("/tmp");
                     97:                exit(1);
                     98:        }
                     99: 
                    100:        tf = fopen(".", "r");
                    101:        if (tf == NULL) {
                    102:                perror("/tmp");
                    103:                exit(1);
                    104:        }
                    105:        while (fread((char *) &dirent, sizeof dirent, 1, tf) == 1) {
                    106:                if (dirent.d_ino == 0)
                    107:                        continue;
                    108:                /*
                    109:                 * Ex temporaries must begin with Ex;
                    110:                 * we check that the 10th character of the name is null
                    111:                 * so we won't have to worry about non-null terminated names
                    112:                 * later on.
                    113:                 */
                    114:                if (dirent.d_name[0] != 'E' || dirent.d_name[1] != 'x' || dirent.d_name[10])
                    115:                        continue;
                    116:                if (stat(dirent.d_name, &stbuf))
                    117:                        continue;
                    118:                if ((stbuf.st_mode & S_IFMT) != S_IFREG)
                    119:                        continue;
                    120:                /*
                    121:                 * Save the bastard.
                    122:                 */
                    123:                ignore(copyout(dirent.d_name));
                    124:        }
                    125:        exit(0);
                    126: }
                    127: 
                    128: char   pattern[] =     usrpath(preserve/Exaa`XXXXX);
                    129: 
                    130: /*
                    131:  * Copy file name into usrpath(preserve)/...
                    132:  * If name is (char *) 0, then do the standard input.
                    133:  * We make some checks on the input to make sure it is
                    134:  * really an editor temporary, generate a name for the
                    135:  * file (this is the slowest thing since we must stat
                    136:  * to find a unique name), and finally copy the file.
                    137:  */
                    138: copyout(name)
                    139:        char *name;
                    140: {
                    141:        int i;
                    142:        static int reenter;
                    143:        char buf[BUFSIZ];
                    144: 
                    145:        /*
                    146:         * The first time we put in the digits of our
                    147:         * process number at the end of the pattern.
                    148:         */
                    149:        if (reenter == 0) {
                    150:                mkdigits(pattern);
                    151:                reenter++;
                    152:        }
                    153: 
                    154:        /*
                    155:         * If a file name was given, make it the standard
                    156:         * input if possible.
                    157:         */
                    158:        if (name != 0) {
                    159:                ignore(close(0));
                    160:                /*
                    161:                 * Need read/write access for arcane reasons
                    162:                 * (see below).
                    163:                 */
                    164:                if (open(name, 2) < 0)
                    165:                        return (-1);
                    166:        }
                    167: 
                    168:        /*
                    169:         * Get the header block.
                    170:         */
                    171:        ignorl(lseek(0, 0l, 0));
                    172:        if (read(0, (char *) &H, sizeof H) != sizeof H) {
                    173: format:
                    174:                if (name == 0)
                    175:                        fprintf(stderr, "Buffer format error\t");
                    176:                return (-1);
                    177:        }
                    178: 
                    179:        /*
                    180:         * Consistency checsks so we don't copy out garbage.
                    181:         */
                    182:        if (H.Flines < 0) {
                    183: #ifdef DEBUG
                    184:                fprintf(stderr, "Negative number of lines\n");
                    185: #endif
                    186:                goto format;
                    187:        }
                    188:        if (H.Blocks[0] != HBLKS || H.Blocks[1] != HBLKS+1) {
                    189: #ifdef DEBUG
                    190:                fprintf(stderr, "Blocks %d %d\n", H.Blocks[0], H.Blocks[1]);
                    191: #endif
                    192:                goto format;
                    193:        }
                    194:        if (name == 0 && H.Uid != getuid()) {
                    195: #ifdef DEBUG
                    196:                fprintf(stderr, "Wrong user-id\n");
                    197: #endif
                    198:                goto format;
                    199:        }
                    200:        if (lseek(0, 0l, 0)) {
                    201: #ifdef DEBUG
                    202:                fprintf(stderr, "Negative number of lines\n");
                    203: #endif
                    204:                goto format;
                    205:        }
                    206: 
                    207:        /*
                    208:         * If no name was assigned to the file, then give it the name
                    209:         * LOST, by putting this in the header.
                    210:         */
                    211:        if (H.Savedfile[0] == 0) {
                    212:                strcpy(H.Savedfile, "LOST");
                    213:                ignore(write(0, (char *) &H, sizeof H));
                    214:                H.Savedfile[0] = 0;
                    215:                lseek(0, 0l, 0);
                    216:        }
                    217: 
                    218:        /*
                    219:         * File is good.  Get a name and create a file for the copy.
                    220:         */
                    221:        mknext(pattern);
                    222:        ignore(close(1));
                    223:        if (creat(pattern, 0600) < 0) {
                    224:                if (name == 0)
                    225:                        perror(pattern);
                    226:                return (1);
                    227:        }
                    228: 
                    229:        /*
                    230:         * Make the target be owned by the owner of the file.
                    231:         */
                    232:        ignore(chown(pattern, H.Uid, 0));
                    233: 
                    234:        /*
                    235:         * Copy the file.
                    236:         */
                    237:        for (;;) {
                    238:                i = read(0, buf, BUFSIZ);
                    239:                if (i < 0) {
                    240:                        if (name)
                    241:                                perror("Buffer read error");
                    242:                        ignore(unlink(pattern));
                    243:                        return (-1);
                    244:                }
                    245:                if (i == 0) {
                    246:                        if (name)
                    247:                                ignore(unlink(name));
                    248:                        notify(H.Uid, H.Savedfile, (int) name);
                    249:                        return (0);
                    250:                }
                    251:                if (write(1, buf, i) != i) {
                    252:                        if (name == 0)
                    253:                                perror(pattern);
                    254:                        unlink(pattern);
                    255:                        return (-1);
                    256:                }
                    257:        }
                    258: }
                    259: 
                    260: /*
                    261:  * Blast the last 5 characters of cp to be the process number.
                    262:  */
                    263: mkdigits(cp)
                    264:        char *cp;
                    265: {
                    266:        register int i, j;
                    267: 
                    268:        for (i = getpid(), j = 5, cp += strlen(cp); j > 0; i /= 10, j--)
                    269:                *--cp = i % 10 | '0';
                    270: }
                    271: 
                    272: /*
                    273:  * Make the name in cp be unique by clobbering up to
                    274:  * three alphabetic characters into a sequence of the form 'aab', 'aac', etc.
                    275:  * Mktemp gets weird names too quickly to be useful here.
                    276:  */
                    277: mknext(cp)
                    278:        char *cp;
                    279: {
                    280:        char *dcp;
                    281:        struct stat stb;
                    282: 
                    283:        dcp = cp + strlen(cp) - 1;
                    284:        while (isdigit(*dcp))
                    285:                dcp--;
                    286: whoops:
                    287:        if (dcp[0] == 'z') {
                    288:                dcp[0] = 'a';
                    289:                if (dcp[-1] == 'z') {
                    290:                        dcp[-1] = 'a';
                    291:                        if (dcp[-2] == 'z')
                    292:                                fprintf(stderr, "Can't find a name\t");
                    293:                        dcp[-2]++;
                    294:                } else
                    295:                        dcp[-1]++;
                    296:        } else
                    297:                dcp[0]++;
                    298:        if (stat(cp, &stb) == 0)
                    299:                goto whoops;
                    300: }
                    301: 
                    302: /*
                    303:  * Notify user uid that his file fname has been saved.
                    304:  */
                    305: notify(uid, fname, flag)
                    306:        int uid;
                    307:        char *fname;
                    308: {
                    309:        struct passwd *pp = getpwuid(uid);
                    310:        register FILE *mf;
                    311:        char cmd[BUFSIZ];
                    312: 
                    313:        if (pp == NULL)
                    314:                return;
                    315:        sprintf(cmd, "mail %s", pp->pw_name);
                    316:        mf = popen(cmd, "w");
                    317:        if (mf == NULL)
                    318:                return;
                    319:        setbuf(mf, cmd);
                    320:        if (fname[0] == 0) {
                    321:                fprintf(mf,
                    322: "A copy of an editor buffer of yours was saved when %s.\n",
                    323:                flag ? "the system went down" : "the editor was killed");
                    324:                fprintf(mf,
                    325: "No name was associated with this buffer so it has been named \"LOST\".\n");
                    326:        } else
                    327:                fprintf(mf,
                    328: "A copy of an editor buffer of your file \"%s\"\nwas saved when %s.\n", fname,
                    329:                /*
                    330:                 * "the editor was killed" is perhaps still not an ideal
                    331:                 * error message.  Usually, either it was forcably terminated
                    332:                 * or the phone was hung up, but we don't know which.
                    333:                 */
                    334:                flag ? "the system went down" : "the editor was killed");
                    335:        fprintf(mf,
                    336: "This buffer can be retrieved using the \"recover\" command of the editor.\n");
                    337:        fprintf(mf,
                    338: "An easy way to do this is to give the command \"ex -r %s\".\n",fname);
                    339:        fprintf(mf,
                    340: "This works for \"edit\" and \"vi\" also.\n");
                    341:        pclose(mf);
                    342: }
                    343: 
                    344: /*
                    345:  *     people making love
                    346:  *     never exactly the same
                    347:  *     just like a snowflake 
                    348:  */
                    349: 
                    350: #ifdef lint
                    351: Ignore(a)
                    352:        int a;
                    353: {
                    354: 
                    355:        a = a;
                    356: }
                    357: 
                    358: Ignorl(a)
                    359:        long a;
                    360: {
                    361: 
                    362:        a = a;
                    363: }
                    364: #endif

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