mmap text file

[Ssagarr Patil]

Hi,

I am trying to achieve faster file writes using mmap.

so I am trying the follwowing:

/* open file */


while (loop) {
        /* get the current file size of output file */
        filesize = lseek(outfd, 0, SEEK_END);

        /* Increase file size */
        ftruncate(outfd, (off_t)filesize + (off_t)buf.size);
        
            /* mmap destination file */
            if((dest = mmap(0, buf.size, PROT_WRITE, MAP_SHARED, outfd, filesize)) == (void *) -1) {
                printf( "Error mapping ouput file: %s: %d, %d\n", argv[1], i, filesize);
                perror("MMAP Failed\n");
                goto error;
            }

    memcpy(dest, src, size);
    munmap(dest);
}

I am able to only mmap it once next time it fails to mmap, any pointers why it fails ?

Regards,
--Sagar