gdb调试技巧 32位和64位

macintosh

apple:socket apple$ gcc test64.c
apple:socket apple$ ./a.out
__x86_64__apple:socket apple$
apple:socket apple$ gcc -m32 test64.c
apple:socket apple$ ./a.out
__i386__apple:socket apple$
代码如下
#include <stdio.h>int main(int argc  ,char* argv){   #ifdef __x86_64__        printf("__x86_64__");   #elif __i386__        printf("__i386__");   #endif   return 0;}
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写了个socket，64位系统保错，32位不报错
使用gcc -m32 -o server server.c 编译解决
/* server.c */#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include <sys/socket.h>#include <netinet/in.h>#define MAXLINE 80#define SERV_PORT 8000int main(void){struct sockaddr_in servaddr, cliaddr;socklen_t cliaddr_len;int listenfd, connfd;char buf[MAXLINE];char str[INET_ADDRSTRLEN];int i, n;listenfd = socket(AF_INET, SOCK_STREAM, 0);bzero(&servaddr, sizeof(servaddr));servaddr.sin_family = AF_INET;servaddr.sin_addr.s_addr = htonl(INADDR_ANY);servaddr.sin_port = htons(SERV_PORT);    bind(listenfd, (struct sockaddr *)&servaddr, sizeof(servaddr));listen(listenfd, 20);printf("Accepting connections ...\n");while (1) {cliaddr_len = sizeof(cliaddr);connfd = accept(listenfd, (struct sockaddr *)&cliaddr, &cliaddr_len);  n = read(connfd, buf, MAXLINE);printf("received from %s at PORT %d\n",       inet_ntop(AF_INET, &cliaddr.sin_addr, str,sizeof(str)),       ntohs(cliaddr.sin_port));    for (i = 0; i < n; i++)buf[i] = toupper(buf[i]);write(connfd, buf, n);close(connfd);}}
client:
#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include <sys/socket.h>#include <netinet/in.h>#define MAXLINE 80#define SERV_PORT 8000int main(int argc, char *argv[]){struct sockaddr_in servaddr;char buf[MAXLINE];int sockfd, n;char *str;    if (argc != 2) {fputs("usage: ./client message\n", stderr);exit(1);}str = argv[1];    sockfd = socket(AF_INET, SOCK_STREAM, 0);bzero(&servaddr, sizeof(servaddr));servaddr.sin_family = AF_INET;inet_pton(AF_INET, "127.0.0.1", &servaddr.sin_addr);servaddr.sin_port = htons(SERV_PORT);    connect(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr));write(sockfd, str, strlen(str));n = read(sockfd, buf, MAXLINE);printf("Response from server:\n");write(STDOUT_FILENO, buf, n);close(sockfd);return 0;}


查找问题的时候参考这个链接http://jimmyleeee.blog.163.com/blog/static/930961820103822435873/