实战演练参考答案

1、实战演练参考答案第1章 Linux系统概述1. 略（见光盘中的视频讲解）2. #who#uname -r3. #echo $SHELL# /bin/csh4. #mkdir /home/temp5. #cp /root/hello /home/temp/hello6. #chmod 755 /home/temp/hello7. 略（见光盘中的视频讲解）8. $HOME Hello World9. #ifconfig eth0 10. #netstat -all第2章 C语言编程基础1.#include <stdio.h>int main(void) printf("*n&

2、quot;); printf(" Hello, Linux world! n"); printf("*n"); return 0;2.main() char ch; scanf("%c",&ch); ch=(ch>='A'&&ch<='Z')?(ch+32):ch; printf("%c",ch);3.#include <stdio.h>int main(void) int x,y; printf("please input

3、x: n"); scanf("%d",&x); if(x<1) y=x; else if(x>=1&&x<10) y=2*x-1; else y=3*x-8; printf("y = %d",y); return 0;4.#include<stdio.h> int main(void) double f,c; int a; printf("please input the type number of Temp:n"); printf("0 : Fahrenhe

4、it -> Celsiusn"); printf("1 : Celsius -> Fahrenheitn"); scanf("%d",&a); if(a=0) scanf("%lf",&f); printf("%lfn",(f-32)*(5/9.0); else scanf("%lf",&c); printf("%lfn",(c*1.8)+32); return 0;5.#include<stdio.h> int ma

5、in(void) int i,j,m,n; double a5;double b5; double s=0; for(i=0; i<5; i+) scanf("%lf",&ai); for(j=0; j<5; j+) bj=1.0/aj; for(m=0; m<5; m+) printf("%f ",bm); for(n=0; n<5; n+) s = s + bn; printf("n %f n",s); return 0;6.#include <stdio.h>int main(void

6、) int i,j,row=0,colum=0,max; int a34 = 1,2,3,4,9,8,7,6,-10,10,-5,2; max=a00; for(i=0;i<=2;i+) for(j=0;j<=3;j+) if(aij>max) max=aij; row=i; colum=j; printf("max = %d,row = %d, colum = %dn",max,row,colum); return 0;7.float func(int n) float f; if(n<0) printf("n<0, dataerr

7、or!n"); else if(n=0|n=1) f=1; else f=func(n-1)*n; return f;main() int n; float y; printf("pleale input an integer:"); scanf("%d",&n); y=func(n); printf("%d! = %10.0f",n,y);8.#include <stdio.h> int main() double a1000; double s=0; int i; int z; for(i=0;i+)

8、 if(!scanf("%lf",&ai) break; for(z=0;z<i;z+) s = s + az; s=s/i; printf("%f",s);9.#include <stdio.h> #include <string.h>struct address char name30; int phone;int main(void) int m,n; char a30; struct address stu3; for(m=0; m<3; m+) scanf("%s",&st

9、); scanf("%d",&stum.phone); scanf("%s",&a); for(n=0; n<3; n+) if(!strcmp(a,) printf("%s,%dn",,stun.phone); return 0;10.#include<stdio.h>node *insert_node(node *head, node *item) /head != NULL node *p = head; node *q = NULL; /始终指

10、向p之前的节点 while(p->data < item->data && p != NULL) q = p; p = p->next; if (p = head) /插入到原头节点之前 item->next = p; return item; q->next = item; item->next = p; return head; /* 两个有序链表进行合并 */ node *merge(node* head1, node* head2) node* head; /合并后的头指针 node *p; node *nextP; /指向p之

11、后 if ( head1 = NULL ) /有一个链表为空的情况，直接返回另一个链表 return head2; else if ( head2 = NULL ) return head1; / 两个链表都不为空 if(length(head1) >= length(head2) /选取较短的链表 /这样进行的插入次数要少些 head = head1; p = head2; else head = head2; p = head1; while(p != NULL) nextP = p->next; /保存p的下一个节点 head = insert_node(head, p);

12、/把p插入到目标链表中 p = nextP; /指向将要插入的下一个节点 return head; node *MergeRecursive(node *head1, node *head2) node *head = NULL; if (head1 = NULL) return head2; if (head2 = NUL) return head1; if ( head1->data < head2->data ) head = head1 ; head->next = MergeRecursive(head1->next,head2); else head

13、= head2 ; head->next = MergeRecursive(head1,head2->next); return head ; int main(void) node *head1 = create(); /创建单链表1 node *head2 = create(); /创建单链表2 node *head = MergeRecursive(head1, head2); print(head); return 0; 第3章 vi与Emacs编辑器1. 略（见光盘中的视频讲解）2. 如图3.2所示3. 如表3.5所示：i表示从光标所在的位置开始插入新的字符I表示从光标所

14、在行的行首开始插入新的字符a表示从光标所在位置的下一个字符开始插入新的输入字符A表示从光标所在行的行尾开始插入新的字符o表示新增加一行，并将光标移动到下一行的开头开始插入字符O表示在当前行的上面新增加一行，并将光标移动到上一行的开头开始插入字符4. #vi /usr/src/linux-8/kernel/fork.c5. #vi /usr/src/linux-8/kernel/fork.c 键入“/”进入底行模式，然后输入字符串“fork”，键入回车后便会自动查找当前文档中的“fork” 字符串。6. 略（见光盘中的视频讲解）7. 略（见光盘中的视频讲解）8. 使用“C-x 2”快捷键可将当前

15、窗口均分为两个工作窗口9. #Emacs /root/install.log 键入“C-s”进入Emacs的搜索模式，然后再输入想要查找的字符“i”10. 键入“M-!”，Emacs进入Shell模式，此时便可在Emacs的命令行输入ls、pwd、who、uname等命令并运行之。第4章 gcc编译器与gdb调试器1.#include <stdio.h>main() int i,j,k; for(i=1; i<=4; i+) for(j=1; j<=4; j+) if(i>=j) k=i+j; printf("%d+%d=%d ",i,j,k)

16、; printf("n"); 2. 比如头文件myhead.h存放在/home/zhangfan/include目录下，则应使用下面的编译命令：# gcc main.c -I /home/zhangfan/include -o main3. 略（见光盘中的视频讲解）4. #gcc v #gdb5. 改正后的程序如下：#include <stdio.h>main() int num1,num2; printf("Input two numbers: "); scanf("%d %d",&num1,&num2)

17、; max(num1, num2);int max(int i, int j) if(i>j) return(i); else return(j);6. (gdb)print k7. (gdb)display k8. (gdb)info line main.c:max第5章 make的使用和Makefile的编写1.all : main.c fun1.c fun2.c fun3.cgcc main.c fun1.c fun2.c fun3.c -o all2. clean:rm -f *.o3. 用“.PHONY : phonyall”声明了phonyall这个目标为伪目标：phonya

18、ll : prog1 prog2 prog3.PHONY : phonyall4. 使用“$”符号表示引用变量值：var= Hello, Linux C programecho $var5.$(subst e, E, sweat will become to sweet)6.$(wordlist 2, 8, I like Linux C programs)7.$(notdir /root/install.log /home/zhangfan/hello.txt hello.c)8.$(suffix hello.c foo.s fun.o usr/src/linux-2.4/Makefile)第

19、6章 文件I/O操作1. #ls -l > filelist2. #pwd >> filelist3. #xxx 2>> filelist4.#include <sys/types.h>#include <sys/stat.h>#include <fcntl.h>#include <stdio.h>#include <string.h>#define FLAGS O_RDONLY /*定义flags：只读方式*/#define PATHNAME "/usr/src/linux-8/init/ma

20、in.c"int main(void) int fd; /*文件描述符*/ if(fd=open(PATHNAME, FLAGS)=-1) /*调用open函数*/ printf("error,open file failed!n"); exit(1); /*出错退出*/ printf("OK,open file successful!n"); printf("fd=%dn",fd); return 0;5.#include <sys/types.h>#include <sys/stat.h>#inc

21、lude <fcntl.h>#include <unistd.h>#include <stdio.h>#include <string.h>#define FILENAME "/home/zhangfan/test" /*要进行写操作的文件*/#define SIZE 80 /*定义缓冲区大小*/#define FLAGS O_RDWR | O_APPEND#define MODE S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH int main(void) int fd; /*

22、文件描述符*/ char write_bufSIZE; /*写缓冲区*/ const char *pathname = FILENAME; /*指向需要打开文件的路径名*/ if(fd=open(pathname,FLAGS,MODE)=-1) /*调用open函数打开文件*/ printf("error,open file failed!n"); exit(1); /*出错退出*/ printf("OK,open file successful!n"); printf("Begin write:n"); gets(write_buf

23、); if(write(fd, write_buf, strlen(write_buf)=-1) printf("error,write file failed!n"); exit(1); /*写出错，退出*/ return 0;6.#include <sys/types.h>#include <sys/stat.h>#include <fcntl.h>#include <stdio.h>#define FLAGS O_RDWR /*定义flags：读写方式*/#define FILENAME "filelist&q

24、uot;int main(void) int fd; /*文件描述符*/ if(fd=open(FILENAME, FLAGS)=-1) /*调用open函数*/ printf("error,open file failed!n"); exit(1); /*出错退出*/ if(lseek(fd, 10, SEEK_SET)=-1) printf("lseek error!n"); exit(1); /*出错退出*/ else printf("lseek OK!n"); exit(0);7.#include <sys/types.

25、h>#include <sys/stat.h>#define PATHNAME "/home/zhangfan/temp"#define MODE S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH int main(void) if(mkdir(PATHNAME, MODE)=-1) printf("make dir error!n"); exit(1); else printf("make dir successfuly!n"); return 0;8.#include

26、 <sys/types.h>#include <unistd.h>#include <stdio.h>#define MODE 0755/*定义参数MODE ：文件所有者读、写、执行；组读、执行；其他读、执行方式*/int main(void) if(chmod("filelist",MODE) = -1) /*调用chmod函数改变文件权限*/ printf("error,change failed!n"); exit(1); /*出错退出*/ printf("OK,change successful!n&

27、quot;); return 0;9.#include <stdio.h>int main(void) if(rename("/home/zhangfan/hello.txt", "/home/zhangfan/temp.txt")=-1) printf("error, rename failed!n"); exit(1); /*出错退出*/ printf("OK, rename successful!n"); return 0;10.#include <unistd.h>int main(

28、void) if(link("/home/zhangfan/hello.txt", "/root/hello.txt")=-1) printf("error, link failed!n"); exit(1); /*出错退出*/ printf("OK, link successful!n"); return 0;第7章 基于流的I/O操作1.#include <stdio.h>int main(void) printf("stdin is "); if(stdin->_flag

29、s & _IO_UNBUFFERED) /*判断标准输入流对象的缓冲区类型*/ printf("unbufferedn"); /*无缓存*/ else if(stdin->_flags & _IO_LINE_BUF) printf("line-bufferedn"); /*行缓存*/ else printf("fully-bufferedn"); /*全缓存*/ printf("buffer size is %dn", stdin->_IO_buf_end - stdin->_IO

30、_buf_base); /*打印缓冲区的大小*/ printf("file discriptor is %dnn", fileno(stdin); /*标准输入流的文件描述符*/ return 0;2.#include <stdio.h>#include <fcntl.h>int main(void) FILE *fp; if(fp = fopen("/root/install.log", "r") = NULL) printf("fail to open!n"); exit(1); /*出

31、错退出*/ printf("open successfuly!n"); fclose(fp); return 0;3.#include <stdio.h>#include <stdlib.h>#define Src_File "/home/zhangfan/hello"#define Des_File "/home/zhangfan/tmp"int main(void) FILE *fp1, *fp2; /*源文件和目标文件的文件指针*/ int c; /*要进行输入和输出的字符*/ if(fp1 = fope

32、n(Src_File, "rb") = NULL) /*以只读方式打开源文件*/ printf("fail to open source filen"); exit(1); /*出错退出*/ if(fp2 = fopen(Des_File, "wb") = NULL) /*以只写方式打开目标文件*/ printf ("fail to open des filen"); exit(1); while(c = fgetc(fp1) != EOF) if(fputc(c, fp2) = EOF) printf (&quo

33、t;fail to writen"); exit(1); /*出错退出*/ fclose(fp1); /*操作完毕，关闭源文件和目标文件*/ fclose(fp2); return 0;第4题参见程序7.65.#include <stdio.h>#define File_path "/home/zhangfan/tmp"int main(void) FILE *fp; /*指向操作文件的文件指针*/ char buf ="Linux C program." fp=fopen(File_path,"w"); /*以

34、只写方式打开文件*/ fprintf(fp, "%s", buf); /*向该文件流输出字符串数据buf*/ fclose(fp); /*关闭文件流*/ return 0;第6题参见程序7.67.#include <stdio.h>#define File_path " "int main(void)FILE *fp;char buf 1024;fp=fopen(File_path, "r");fscanf(fp,"%s",&buf);fclose(fp);printf("%sn&qu

35、ot;,buf);return 0;第8章 进程控制1. #ps # ps -aux2. kill3.#include <sys/types.h>#include <unistd.h>main()printf("The current process ID is %dn",getpid();4.#include <sys/types.h>#include <unistd.h>#include <stdio.h>int main (void)pid_t pid; /*此时仅有一个进程*/ if(pid=fork()

36、< 0) printf("error in fork!"); exit(1); /* fork出错退出*/ else if(pid=0) printf("Child process ID is %dn", getpid(); else printf("Parent process ID is %dn", getpid(); return 0;5.#include <sys/types.h>#include <unistd.h>#include <stdio.h>int main (void)i

37、nt count = 1; int child; if(child= vfork() < 0) printf("error in vfork!"); exit(1); /* fork出错退出*/ if(child=0) /*子进程*/ printf("This is son, his pid is: %d and the count is: %dn", getpid(), +count); exit(1); else /*父进程*/ printf("After son, This is father, his pid is: %d and

38、 the count is: %d, and the child is: %dn", getpid(), count, child); return 0;6.#include <stdlib.h>int main(void)printf("Hello, world!n"); exit(0); printf("Hello, world again!n");7.#include <stdlib.h> int main(void) printf("nparent process, output beginn"

39、;); printf("parent process, content in buffer"); /*没有换行符n*/ _exit(0); 8.#include <sys/types.h>#include <sys/wait.h>#include <unistd.h>#include <stdio.h>int main(void) pid_t pc,pr; if (pc = fork() < 0) printf("error in fork!"); exit(1); /* fork出错退出*/ els

40、e if(pc=0) /*子进程*/ printf("This is child process with pid of %dn",getpid(); sleep(10); /*睡眠10秒钟*/ else /*父进程*/ pr=wait(NULL); /*在这里等待*/ exit(0);9.#include <stdlib.h>#include <stdio.h>int main(void) int status; if (status = system("date") < 0) printf("system er

41、ror!n"); exit(0); if (status = system("ls") < 0) printf("system error!n"); exit(0); if (status = system("pwd") < 0) printf("system error!n"); exit(0); return 0;10.#include <sys/types.h>#include <unistd.h>main()printf("The current pr

42、ocess ID is %dn",getpgrp();第9章 信号1. #kill -l2.#include <signal.h>#include <stdio.h>void SignHandler(int iSignNum) printf("Capture signal number:%dn",iSignNum); int main(void) signal(SIGQUIT,SignHandler); while(1) sleep(1); return 0;3.#include <signal.h>#include <s

43、tdio.h>int main(void) signal(SIGQUIT,SIG_IGN); while(1) sleep(1); return 0;4.#include <stdio.h>#include <string.h>#include <unistd.h>#include <signal.h>int g_iSeq=0;void SignHandlerNew(int iSignNo,siginfo_t *pInfo,void *pReserved) int iSeq=g_iSeq+; printf("%d Enter Si

44、gnHandlerNew,signo:%d.n",iSeq,iSignNo); sleep(3); /*睡眠3秒钟*/ printf("%d Leave SignHandlerNew,signo:%dn",iSeq,iSignNo);int main(void) struct sigaction act; act.sa_sigaction=SignHandlerNew; act.sa_flags=SA_SIGINFO; sigemptyset(&act.sa_mask); sigaction(SIGINT,&act,NULL); sigaction

45、(SIGQUIT,&act,NULL); return 0;5.#include<unistd.h>#include<signal.h>#include<sys/types.h>#include<sys/wait.h>#include<stdio.h>int main(void)pid_t pid;int status;if(!(pid= fork()printf("Hi I am child process!n");sleep(10); printf("Hi I am child process

46、, again!n");return;elseprintf("send signal to child process (%d) n",pid);sleep(1);if(kill(pid ,SIGABRT) = -1) printf("kill failed!n"); return 0;6.#include <sys/types.h>#include <signal.h>int main(void) printf("Hello, I like Linux C programs!n"); if(rais

47、e(SIGABRT) = -1) printf("raise failed!n"); exit(1); printf("Hello, I like Linux C programs,again!n"); return 0;7.#include<stdio.h>#include<signal.h>#include<unistd.h>void SigHandler(int signo,siginfo_t *info,void *context) char *pMsg=(char*)info->si_value.siv

48、al_ptr; printf("Receive signal number:%dn", signo); printf("Receive Message:%sn", pMsg);int main(void) struct sigaction sigAct; sigAct.sa_flags=SA_SIGINFO; sigAct.sa_sigaction=SigHandler; if(sigaction(SIGUSR1,&sigAct,NULL)=-1) printf("sigaction failed!n"); exit(1);

49、sigval_t val; char pMsg ="I like Linux C programs!" val.sival_ptr = pMsg; if(sigqueue(getpid(),SIGUSR1,val) = -1) printf("sigqueue failed!n"); exit(1); sleep(3); return 0;8.#include<unistd.h>#include<signal.h>void handler()printf("Hello, I like Linux C programs!n

50、");int main(void)int i;signal(SIGALRM,handler);alarm(3);for(i=1;i<5;i+)printf("sleeping %d .n",i);sleep(1); return 0;9.#include <stdio.h>#include <string.h>#include <unistd.h>#include <signal.h>int g_iSeq=0;void SignHandlerNew(int iSignNo,siginfo_t *pInfo,vo

51、id *pReserved) int iSeq=g_iSeq+; printf("%d Enter SignHandlerNew,signo:%d.n",iSeq,iSignNo); sleep(3); printf("%d Leave SignHandlerNew,signo:%dn",iSeq,iSignNo); int main(void) struct sigaction act; act.sa_sigaction=SignHandlerNew; act.sa_flags=SA_SIGINFO; sigset_t sigSet; sigempty

52、set(&sigSet); sigaddset(&sigSet,SIGINT); sigprocmask(SIG_BLOCK,&sigSet,NULL); sigemptyset(&act.sa_mask); sigaction(SIGINT,&act,NULL); /*注册SIGINT信号*/ sigaction(SIGQUIT,&act,NULL); /*注册SIGQUIT信号*/ return 0;10.#include <signal.h> #include <stdio.h>#include <unistd.h>void SignHandler(int iSignNo) printf("signal:%dn",iSignNo)