/********************************************************************************* *      Copyright:  (C) 2016 Guo Wenxue<guowenxue@aliyun.com> *                  All rights reserved. * *       Filename:  strhex.c *    Description:  This file used convert HEX string to HEX bytes and write into file *                  *        Version:  1.0.0(09/20/2016) *         Author:  Guo Wenxue <guowenxue@aliyun.com> *      ChangeLog:  1, Release initial version on "09/20/2016 09:16:41 AM" *                  ********************************************************************************/#include <stdio.h>#include <string.h>#include <unistd.h>#include <sys/types.h>#include <sys/stat.h>#include <fcntl.h>#include <errno.h>//#define DEBUG#ifdef  DEBUG#define dbg_print(format,args...) printf(format, ##args)#else#define dbg_print(format,args...) do{} while(0);#endifint hexStr2Bytes(char *hexstr, int strlen, unsigned  char *bytes){    int           i;    int           cnt = 0;     for(i=0; i<strlen; i++)    {        dbg_print("%c", hexstr[i]);    }    dbg_print("\n");    for (i=0; i<strlen; i++)    {        if( !isxdigit(hexstr[i]) )        {            continue;        }        dbg_print("proc ‘%c‘ ", hexstr[i]);        if ((hexstr[i] >= ‘0‘) && (hexstr[i] <= ‘9‘))            *bytes = (hexstr[i]-‘0‘) << 4;        else             *bytes = (toupper(hexstr[i])-‘A‘+10) <<4;        dbg_print("[0x%02x] ", *bytes);               i++;        dbg_print("proc ‘%c‘ ", hexstr[i]);        if ((hexstr[i] >= ‘0‘) && (hexstr[i] <= ‘9‘))             *bytes |= hexstr[i]-‘0‘;        else             *bytes |= toupper(hexstr[i])-‘A‘+10;        dbg_print("=>[0x%02x]\n", *bytes);        bytes++;        cnt ++;    }    return cnt;}int main (int argc, char **argv){    char                *filename;    unsigned char       buf[1024];    char                *hexstr;    int                 bytes;    int                 fd;    int                 i;     if(argc != 3 )    {        printf("Usage: %s [filename] [hexstr]\n", argv[0]);        return -1;    }    filename = argv[1];    hexstr = argv[2];    if( (fd=open(filename, O_CREAT|O_TRUNC|O_RDWR, 0666)) < 0 )    {        printf("Open file ‘%s‘ failure: %s\n", filename, strerror(errno));        return -2;    }    bytes = hexStr2Bytes(hexstr, strlen(hexstr), buf);    write(fd, buf, bytes);    close(fd);    return 0;}