c读写文件与文件参数管理

来源：互联网发布：linux set pythonpath 编辑：程序博客网时间：2024/06/14 03:08
直接上代码，代码简单易懂。
#include<stdio.h>#define PARAM_CONFIG "/home/lkg/test/config"typedef struct{    unsigned short int id;    int offset;}param_offset;typedef struct {    char c;    int h;    unsigned short n;    char s[4];}st;  ram_offset id_offset[3] =  {▽   {1,0},    {2,8},                        {3,108},                  };                                                                                                                                                                              int param_write_cfg(st* buffer, unsigned short int param_id){    int ret, i, offset;    FILE *fp;    i = 0;    while(id_offset && id_offset[i].id){        if(param_id == id_offset[i].id){            offset = id_offset[i].offset;            break;        }        i++;    }    printf("id = %d, offset = %d\n", param_id, offset);            if((fp = fopen(PARAM_CONFIG, "rb+")) == NULL) {        if((fp = fopen(PARAM_CONFIG, "wb+")) == NULL) {            printf("Can't open %s, program will to exit.\n", PARAM_CONFIG);            return -1;        }    }    fseek(fp, offset, SEEK_SET);    fwrite(buffer, sizeof(*buffer), 1, fp);    printf("st c = %d, h = %d n =%u s = %s \n",buffer->c, buffer->h,buffer->n,buffer->s);     fclose(fp);    return 0;}int param_read_cfg(st* buffer, unsigned short int param_id){    int ret, i, offset;    FILE *fp; ~/test/param.c[+1]                                                                                                                                      [c] unix utf-8 1:17/81 "param.c" 81L, 2187C writtenlkg@ubuntu:~/test$ gcc param.c lkg@ubuntu:~/test$ ./a.out id = 2, offset = 8st c = 5, h = 7 n =0 s = didi id = 3, offset = 108st c = 6, h = 2 n =0 s = dada id = 2, offset = 8st c = 5, h = 7 n =0 s = didi id = 3, offset = 108st c = 6, h = 2 n =0 s = dada lkg@ubuntu:~/test$ vi param.c  * *读取文件指定id位置存储的结构体内容 * */int param_read_cfg(st* buffer, unsigned short int param_id){    int ret, i, offset;    FILE *fp;    param_offset id_offset[3] =  {        {1,0},        {2,8},                                     {3,108},                               };      i = 0;    while(id_offset && id_offset[i].id){        if(param_id == id_offset[i].id){            offset = id_offset[i].offset;            break;        }           i++;    }       printf("id = %d, offset = %d\n", param_id, offset);                if((fp = fopen(PARAM_CONFIG, "rb+")) == NULL) {        printf("Can't open %s, program will to exit.", PARAM_CONFIG);        return -1;     }       fseek(fp, offset, SEEK_SET);    fread(buffer, sizeof(*buffer), 1, fp);    printf("st c = %d, h = %d n =%u s = %s \n",buffer->c, buffer->h,buffer->n,buffer->s);    fclose(fp);    return 0;  }int main(){//    char version[] = "1.0.5";    st t;    st tt = {5,7,0,"didi"};    st tt1 = {6,2,0,"dada"};//    param_write_cfg(version,1);    param_write_cfg(&tt,2);    param_write_cfg(&tt1,3);    param_read_cfg(&t,2);    param_read_cfg(&t,3);    return 0;}
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