我从 StackOverflow 上的其他帖子中看到, undefined reference 错误意味着缺少定义,通常要修复它,必须在编译中链接文件。但我只编译一个文件。我收到函数 pthread_detach
和 pthread_create
的错误。
/tmp/ccAET7bU.o: In function `sample_thread1':
foo.c:(.text+0x2a): undefined reference to `pthread_detach'
/tmp/ccAET7bU.o: In function `main':
foo.c:(.text+0x85): undefined reference to `pthread_create'
collect2: error: ld returned 1 exit status
代码:
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <memory.h>
#include <signal.h>
#include <string.h>
#include <linux/unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/syscall.h>
#include <netinet/in.h>
#include <pthread.h>
pid_t gettid(void)
{
return syscall(__NR_gettid);
}
void *sample_thread1(void *x_void_ptr)
{
FILE *fp;
int counter;
pthread_detach(pthread_self());
if((fp = fopen("thread_data.txt", "w")) == NULL)
{
printf("ERROR : Thread cannot open data file.\n");
return;
}
counter = 1;
while(1);
{
fprintf(fp, "INFO : Thread1 id %d output message %10d\n",
gettid(), counter);
fflush(fp);
counter++;
sleep(1);
}
pthread_exit(NULL);
}
int main(int argc, char *argv[])
{
int counter;
pthread_t sample_thread_t1;
if(pthread_create(&sample_thread_t1, NULL, sample_thread1, NULL))
{
fprintf(stderr, "Error creating thread\n");
exit(-1);
}
system("clear");
counter = 1;
while(1)
{
printf("INFO : Main Process Counter = %d\n", counter);
counter++;
sleep(1);
}
return(0);
}
最佳答案
您必须使用 GCC 或 clang 的 -lpthread
或 -pthread
选项将其与 pthread
库链接。
例子:
gcc your_file.c -o program -lpthread
# or gcc your_file.c -o program -pthread
# the same for clang
关于c - 单个文件的 undefined reference ,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/30004893/