Cat & Split

/*

 * Copyright (c) 2005 by Romuald DELAVERGNE

 * It can be redistributed under the terms of the GNU General Public License.

*/

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

#include <sys/stat.h>

#include <io.h>

void

exitOnError(char *msg) {

        perror(msg);

        exit(1);

}

int

main(int argc, char *argv[]) {

        void *buf;

        struct stat statFileIn;

        FILE *fileIn, *fileOut;

        char

                fileName[255],

                *prog = argv[0],

                *prefix = argv[3];

        unsigned long

                nbFiles, lastSize, maxSize, size, nb, nbWrited, nbRest;

        int i;

        buf = malloc(BUFSIZ);

        if (argc < 4) {

                printf("%s: too few parameters !\n", prog);

                printf("split a file into pieces\n");

                printf("usage: %s FILE SIZE PREFIX\n", prog);

                printf("  FILE  : big file to split\n");

                printf("  SIZE  : size in bytes\n");

                printf("  PREFIX: result files without suffix\n");

                exit(0);

        }

        if ((fileIn = fopen(argv[1], "rb")) == NULL) exitOnError(argv[1]);

        if (fstat(fileIn->fd, &statFileIn) == -1) exitOnError(argv[1]);

        if (sscanf(argv[2], "%lu", &maxSize) == 0) {

                fprintf(stderr, "%s: invalid size !\n", argv[2]);

                exit(1);

        }

        nbFiles = statFileIn.st_size/maxSize;

        lastSize = statFileIn.st_size%maxSize;

        if (lastSize > 0) nbFiles++; else lastSize = maxSize;

        i = 0;

        while (i < nbFiles) {

                i++;

                size = (i == nbFiles) ? lastSize: maxSize;

                sprintf(fileName, "%s.%03d", prefix, i);

                if (access(fileName, 0) == 0) {

                        fprintf(stderr, "%s: file already exists !\n", fileName);

                        exit(1);

                }

                if ((fileOut = fopen(fileName, "wb")) == NULL) exitOnError(fileName);

                nbWrited = 0;

                while (nbWrited < size) {

                        nbRest = size - nbWrited;

                        nb = (nbRest < BUFSIZ) ? nbRest: BUFSIZ;

                        if (fread(buf, nb, 1, fileIn) != 1) exitOnError(prog);

                        if (fwrite(buf, nb, 1, fileOut) != 1) exitOnError(prog);

                        nbWrited += nb;

                }

                fclose(fileOut);

        }

        fclose(fileIn);

        return 0;

}