如何使用C（linux）中的管道将GCC的输出保存在文件中？

Question

on execution, file creation is working well...but nothing gets written into it...what could be done...is there any other way apart from using file descriptors..??

I tried the following code:

    memset(buffer, '\0', sizeof(buffer));
    read_fp = popen("gcc test1.c", "r");
    //fp = fopen("/home/pranav/Desktop/b4.txt","w");
    fd = open("beejoutput2.txt", O_CREAT | O_RDWR, S_IRUSR | S_IWUSR | S_IRGRP  |         S_IROTH);
    if (read_fp != NULL)
    {

        chars_read = fread(buffer, sizeof(char), BUFSIZ, read_fp);
        while (chars_read > 0)
        {

    /*writing to the file*/
        while ((bytesread = read(3, buffer, chars_read)) > 0) 
                write(fd, buffer, bytesread);

        buffer[chars_read-1] = '\0';
        printf("Reading %d:-\n %s\n", BUFSIZ, buffer);
        //fprintf(fp,"%d:-\n %s\n", BUFSIZ, buffer);
        chars_read = fread(buffer, sizeof(char), BUFSIZ, read_fp);
        }



    pclose(read_fp);
    exit(EXIT_SUCCESS);
    }
    //fclose(fp);
    exit(EXIT_FAILURE);
    return 0;
    }

Answer 1

Error messages will be on stderr, so change this

read_fp = popen("gcc test1.c", "r");

to this

read_fp = popen("gcc test1.c 2>&1", "r");

Answer 2

1. You should test the output of open and write since they fail.
2. You should not use system calls like open and write directly, they have portable C wrappers like fopen and fwrite .
3. Close all the things at the end.