Return to sunopen.c CVS log

Up to [Research Unix] / researchv10no / cmd / nupas / libc

Annotation of researchv10no/cmd/nupas/libc/sunopen.c, revision 1.1

1.1     ! root        1: #include <stdio.h>
        !             2: #include <sys/types.h>
        !             3: #include <sys/stat.h>
        !             4: #include "string.h"
        !             5: #include "mail.h"
        !             6: 
        !             7: /*
        !             8:  *  open a file for appending.  if the file doesn't exist, create it.
        !             9:  *  return the file descriptor.
        !            10:  */
        !            11: appendopen(file)
        !            12:        char *file;
        !            13: {
        !            14:        int out;
        !            15:        long lseek();
        !            16: 
        !            17:        lock(file);
        !            18:        out = open(file, 2);
        !            19:        if (out < 0)
        !            20:                out = creat(file, 0666);
        !            21:        else
        !            22:                chmod(file, 0666);
        !            23:        lseek(out, 0L, 2);
        !            24:        return out;
        !            25: }
        !            26: 
        !            27: /*
        !            28:  *  close an append only file
        !            29:  */
        !            30: appendclose(fd)
        !            31:        int fd;
        !            32: {
        !            33:        close(fd);
        !            34:        unlock();
        !            35: }
        !            36: 
        !            37: /*
        !            38:  *  lock and open file.  If the file doesn't exist and mode!=0, create it.
        !            39:  *  return the file descriptor.
        !            40:  */
        !            41: 
        !            42: FILE *
        !            43: lockopen(file, omode, pmode, uid, gid)
        !            44:        char *file;
        !            45:        char *omode;
        !            46:        int pmode;
        !            47: {
        !            48:        FILE *fp;
        !            49:        struct stat sbuf;
        !            50:        int newfile;
        !            51: 
        !            52:        lock(file);
        !            53:        if(stat(file, &sbuf)<0)
        !            54:                newfile = 1;
        !            55:        else
        !            56:                newfile = 0;
        !            57:        fp = fopen(file, omode);
        !            58:        if(fp==NULL){
        !            59:                unlock();
        !            60:                return NULL;
        !            61:        }
        !            62:        if(newfile){
        !            63:                chown(file, uid, gid);
        !            64:                chmod(file, pmode);
        !            65:        }
        !            66:        return fp;
        !            67: }
        !            68: 
        !            69: /*
        !            70:  *  close and unlock a file.
        !            71:  */
        !            72: lockclose(fp)
        !            73:        FILE *fp;
        !            74: {
        !            75:        fclose(fp);
        !            76:        unlock();
        !            77: }
        !            78: 
        !            79: /*
        !            80:  *  reopen a file without losing the lock.
        !            81:  */
        !            82: FILE *
        !            83: lockreopen(file, omode, fp)
        !            84:        char *file;
        !            85:        char *omode;
        !            86:        FILE *fp;
        !            87: {
        !            88:        return freopen(file, omode, fp);
        !            89: }
        !            90: 
        !            91: /*
        !            92:  *  remove ALL locks
        !            93:  */
        !            94: cleanlocks()
        !            95: {
        !            96:        unlock();
        !            97: }
        !            98: #ifndef lint
        !            99: static char *sccsid = "@(#)lock.c 1.5 88/02/08 SMI"; /* from S5R2 1.1 */
        !           100: #endif
        !           101: 
        !           102: /*
        !           103:  * mailx -- a modified version of a University of California at Berkeley
        !           104:  *     mail program
        !           105:  *
        !           106:  * Stuff to do version 7 style locking.
        !           107:  */
        !           108: 
        !           109: 
        !           110: char   *maillock       = ".lock";              /* Lock suffix for mailname */
        !           111: #ifdef USG
        !           112: char   *lockname       = "/usr/mail/tmXXXXXX";
        !           113: #else
        !           114: char   *lockname       = "/usr/spool/mail/tmXXXXXX";
        !           115: #endif
        !           116: char   locktmp[30];                            /* Usable lock temporary */
        !           117: static char            curlock[50];            /* Last used name of lock */
        !           118: static int             locked;                 /* To note that we locked it */
        !           119: 
        !           120: /*
        !           121:  * Lock the specified mail file by setting the file mailfile.lock.
        !           122:  * We must, of course, be careful to remove the lock file by a call
        !           123:  * to unlock before we stop.  The algorithm used here is to see if
        !           124:  * the lock exists, and if it does, to check its modify time.  If it
        !           125:  * is older than 5 minutes, we assume error and set our own file.
        !           126:  * Otherwise, we wait for 5 seconds and try again.
        !           127:  */
        !           128: 
        !           129: lock(file)
        !           130: char *file;
        !           131: {
        !           132:        register int f;
        !           133:        struct stat sbuf;
        !           134:        long curtime;
        !           135: 
        !           136:        if (file == (char *)0) {
        !           137:                printf("Locked = %d\n", locked);
        !           138:                return(0);
        !           139:        }
        !           140:        if (locked)
        !           141:                return(0);
        !           142:        strcpy(curlock, file);
        !           143:        strcat(curlock, maillock);
        !           144:        strcpy(locktmp, lockname);
        !           145:        mktemp(locktmp);
        !           146:        remove(locktmp);
        !           147:        for (;;) {
        !           148:                f = lock1(locktmp, curlock);
        !           149:                if (f == 0) {
        !           150:                        locked = 1;
        !           151:                        return(0);
        !           152:                }
        !           153:                if (stat(curlock, &sbuf) < 0)
        !           154:                        return(0);
        !           155:                time(&curtime);
        !           156:                if (curtime < sbuf.st_ctime + 300) {
        !           157:                        sleep(5);
        !           158:                        continue;
        !           159:                }
        !           160:                remove(curlock);
        !           161:        }
        !           162: }
        !           163: 
        !           164: /*
        !           165:  * Remove the mail lock, and note that we no longer
        !           166:  * have it locked.
        !           167:  */
        !           168: 
        !           169: unlock()
        !           170: {
        !           171: 
        !           172:        remove(curlock);
        !           173:        locked = 0;
        !           174: }
        !           175: 
        !           176: /*
        !           177:  * Attempt to set the lock by creating the temporary file,
        !           178:  * then doing a link/unlink.  If it fails, return -1 else 0
        !           179:  */
        !           180: 
        !           181: lock1(tempfile, name)
        !           182:        char tempfile[], name[];
        !           183: {
        !           184:        register int fd;
        !           185: 
        !           186:        fd = creat(tempfile, 0);
        !           187:        if (fd < 0)
        !           188:                return(-1);
        !           189:        close(fd);
        !           190:        if (link(tempfile, name) < 0) {
        !           191:                remove(tempfile);
        !           192:                return(-1);
        !           193:        }
        !           194:        remove(tempfile);
        !           195:        return(0);
        !           196: }

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.