lzw.c.c

Lempel-Ziv coding 源代码（Ｃ）

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "getopt.h"
#include "lzw.h"

char *RemovePath(char *fullPath);

int main(int argc, char *argv[])
{
    int opt;
    char *inFile, *outFile;
    char encode;            

    
    inFile = NULL;
    outFile = NULL;
    encode = TRUE;

    
    while ((opt = getopt(argc, argv, "cdi:o:h?")) != -1)
    {
        switch(opt)
        {
            case 'c':      
                encode = TRUE;
                break;

            case 'd':       
                encode = FALSE;
                break;

            case 'i':      
                if (inFile != NULL)
                {
                    fprintf(stderr, "Multiple input files not allowed.\n");
                    free(inFile);

                    if (outFile != NULL)
                    {
                        free(outFile);
                    }

                    exit(EXIT_FAILURE);
                }
                else if ((inFile = (char *)malloc(strlen(optarg) + 1)) == NULL)
                {
                    perror("Memory allocation");

                    if (outFile != NULL)
                    {
                        free(outFile);
                    }

                    exit(EXIT_FAILURE);
                }

                strcpy(inFile, optarg);
                break;

            case 'o':      
                if (outFile != NULL)
                {
                    fprintf(stderr, "Multiple output files not allowed.\n");
                    free(outFile);

                    if (inFile != NULL)
                    {
                        free(inFile);
                    }

                    exit(EXIT_FAILURE);
                }
                else if ((outFile = (char *)malloc(strlen(optarg) + 1)) == NULL)
                {
                    perror("Memory allocation");

                    if (inFile != NULL)
                    {
                        free(inFile);
                    }

                    exit(EXIT_FAILURE);
                }

                strcpy(outFile, optarg);
                break;

            case 'h':
            case '?':
                printf("Usage: %s <options>\n\n", RemovePath(argv[0]));
                printf("options:\n");
                printf("  -c : Encode input file to output file.\n");
                printf("  -d : Decode input file to output file.\n");
                printf("  -i <filename> : Name of input file.\n");
                printf("  -o <filename> : Name of output file.\n");
                printf("  -h | ?  : Print out command line options.\n\n");
                printf("Default: %s -c\n", RemovePath(argv[0]));
                return(EXIT_SUCCESS);
        }
    }

    
    if (inFile == NULL)
    {
        fprintf(stderr, "Input file must be provided\n");
        fprintf(stderr, "Enter \"%s -?\" for help.\n", RemovePath(argv[0]));

        if (outFile != NULL)
        {
            free(outFile);
        }

        exit (EXIT_FAILURE);
    }
    else if (outFile == NULL)
    {
        fprintf(stderr, "Output file must be provided\n");
        fprintf(stderr, "Enter \"%s -?\" for help.\n", RemovePath(argv[0]));

        if (inFile != NULL)
        {
            free(inFile);
        }

        exit (EXIT_FAILURE);
    }

   
    if (encode)
    {
        LZWEncodeFile(inFile, outFile);
    }
    else
    {
        LZWDecodeFile(inFile, outFile);
    }

    free(inFile);
    free(outFile);
    return EXIT_SUCCESS;
}

char *RemovePath(char *fullPath)
{
    int i;
    char *start, *tmp;                          
    const char delim[3] = {'\\', '/', ':'};    

    start = fullPath;

  
    for (i = 0; i < 3; i++)
    {
        tmp = strrchr(start, delim[i]);

        if (tmp != NULL)
        {
            start = tmp + 1;
        }
    }

    return start;
}