用C语言编写multipart/form-data实现上传文件

#include <stdio.h> #include <sys/types.h> #include <sys/socket.h> #include <unistd.h> #include <arpa/inet.h> #include <string.h> #include <sys/time.h> #include <sys/select.h> #include <fcntl.h> #include <errno.h> #define SERVER_ADDR "192.168.1.123" #define SERVER_PORT 10086 char upload_head[] = "POST /Logupload/upload?userid=%s HTTP/1.1\r\n" "Host: %s:%d\r\n" "Connection: keep-alive\r\n" "Content-Type: multipart/form-data; boundary=%s\r\n" "Content-Length: %d\r\n\r\n" "--%s\r\n" "Content-Disposition: form-data; name=\"file\"; filename=\"%s\"\r\n" "Content-Type: application/octet-stream;chartset=UTF-8\r\n\r\n"; char upload_request[] = "--%s\r\n" "Content-Disposition: form-data; name=\"file\"; filename=\"%s\"\r\n" "Content-Type: application/octet-stream;chartset=UTF-8\r\n\r\n"; int Connect_Server(char *severip,int port) { int sock = -1; struct sockaddr_in addr; if(severip == NULL || port <= 0) return -1; memset(&addr,0,sizeof(addr)); addr.sin_family = AF_INET; addr.sin_port = htons(port); inet_pton(AF_INET,severip,&addr.sin_addr.s_addr); sock = socket(AF_INET,SOCK_STREAM,0); if(-1 == sock) return -1; if(connect(sock,(struct sockaddr*)&addr,sizeof(addr)) < 0) { close(sock); return -1; } return sock; } int main(int argc,char *argv[]) { char filename[256] = {0}; int sock = -1; char send_date[4096] = {0}; char send_end[128] = {0}; char send_request[2048] = {0}; FILE *fp = NULL; char *userid = "00000000199"; char boundary[64] = {0}; int ret = -1,already = -1,ContentLength = -1; long long int timestamp; struct timeval tv; if(argc < 2) return -1; strncpy(filename,argv[1],256); if(access(filename,F_OK) != 0) { printf("file %s not exsit!\n",filename); return -1; } //连接服务器 sock = Connect_Server(SERVER_ADDR,SERVER_PORT); if(sock < 0 ) { printf("connect server error!\n"); return -1; } //打开要上传的文件，获取文件的大小，用于计算Content-Length的大小 fp = fopen(filename,"rb"); if(fp == NULL) { printf("open file %s error!\n",filename); close(sock); return -1; } fseek(fp,0,SEEK_END); ContentLength = ftell(fp); rewind(fp); //获取毫秒级的时间戳用于boundary的值 gettimeofday(&tv,NULL); timestamp = (long long int)tv.tv_sec * 1000 + tv.tv_usec; snprintf(boundary,64,"---------------------------%lld",timestamp); // Content-Length的大小还包括了对上传文件的描述，开始boundary和结束boundary ContentLength += snprintf(send_request,2048,upload_request,boundary,filename); ContentLength +=snprintf(send_end,2048,"\r\n--%s--\r\n",boundary); //发送的http头和上传文件的描述 ret = snprintf(send_date,4096,upload_head,userid,SERVER_ADDR,SERVER_PORT,boundary,ContentLength,boundary,filename); if(send(sock,send_date,ret,0) != ret) { printf("send head error!\n"); close(sock); return -1; } //循环读取文件，并往服务器上面发送，直到文件结束为止 clearerr(fp); while(1) { memset(send_date,0,sizeof(send_date)); ret = fread(send_date,1,4096,fp); if(ret != 4096) { if(!ferror(fp)) { if(send(sock,send_date,ret,0) != ret) { printf("send the end date error!\n"); close(sock); fclose(fp); return -1; } fclose(fp); break; } else { printf("read file error!\n"); close(sock); fclose(fp); return -1; } } if(send(sock,send_date,4096,0) != 4096) { printf("send date error\n"); close(sock); fclose(fp); return -1; } } //发送最后的boundary结束文件上传。 SEND_END: memset(send_date,0,sizeof(send_date)); ret = snprintf(send_date,4096,"\r\n--%s--\r\n",boundary); if(send(sock,send_date,ret,0) != ret) { close(sock); return -1; } printf("send to server end date:%s\n",send_date); //接收返回值，用于判断是否上传成功 memset(send_date,0,sizeof(send_date)); if(recv(sock,send_date,4096,0) < 0) printf("recv error!\n"); printf("recv:%s\n",send_date); close(sock); return 0; }