用c语言编写一个程序，可以在命令行输入参数，完成指定文件的压缩解压 命令行参数如下 rle file1 –c(-d) file2 第一个参数为可执行程序名称，第二个参数为原始文件名，第三个参数为压缩或解压缩选项，第四个参数为新文件名

以下是一个简单的基于C语言的程序，可以实现命令行输入参数，完成指定文件的压缩和解压缩功能：

#include <stdio.h>
#include <stdlib.h>

#define MAX_SIZE 1024

void encode(char *input_file, char *output_file) {
    FILE *in, *out;
    int count = 1, old = -1, new;

    if ((in = fopen(input_file, "rb")) == NULL) {
        printf("Error: Cannot open input file: %s\n", input_file);
        exit(1);
    }

    if ((out = fopen(output_file, "wb")) == NULL) {
        fclose(in);
        printf("Error: Cannot open output file: %s\n", output_file);
        exit(1);
    }

    while ((new = fgetc(in)) != EOF) {
        if (new == old) {
            count++;
            if (count == 256) {
                fputc(count - 1, out);
                fputc(old, out);
                count = 1;
            }
        } else {
            if (count > 1) {
                fputc(count, out);
                fputc(old, out);
            } else {
                fputc(old, out);
            }
            count = 1;
            old = new;
        }
    }

    if (count > 1) {
        fputc(count, out);
        fputc(old, out);
    } else {
        fputc(old, out);
    }

    fclose(in);
    fclose(out);
}

void decode(char *input_file, char *output_file) {
    FILE *in, *out;
    int count, ch;

    if ((in = fopen(input_file, "rb")) == NULL) {
        printf("Error: Cannot open input file: %s\n", input_file);
        exit(1);
    }

    if ((out = fopen(output_file, "wb")) == NULL) {
        fclose(in);
        printf("Error: Cannot open output file: %s\n", output_file);
        exit(1);
    }

    while ((count = fgetc(in)) != EOF) {
        ch = fgetc(in);
        if (count > 1) {
            for (int i = 0; i < count; i++) {
                fputc(ch, out);
            }
        } else {
            fputc(ch, out);
        }
    }

    fclose(in);
    fclose(out);
}

int main(int argc, char **argv) {
    char *input_file, *output_file;
    int option;

    if (argc != 5) {
        printf("Usage: rle input_file -c/-d output_file\n");
        exit(1);
    }

    input_file = argv[2];
    option = argv[3][1];
    output_file = argv[4];

    switch (option) {
        case 'c':
            encode(input_file, output_file);
            printf("File \"%s\" has been compressed as \"%s\".\n", input_file, output_file);
            break;
        case 'd':
            decode(input_file, output_file);
            printf("File \"%s\" has been decompressed as \"%s\".\n", input_file, output_file);
            break;
        default:
            printf("Error: Invalid option \"%c\".\n", option);
            exit(1);
            break;
    }

    return 0;
}

编译命令：

gcc rle.c -o rle

使用示例：

./rle file1 -c file2
./rle file2 -d file3

其中，`file1` 是原始文件名，`file2` 是压缩后的文件名，`file3` 是解压后的文件名。`-c` 表示压缩选项，`-d` 表示解压选项。