实战演练参考答案.doc

31 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 00 netmask gw 10. #netstat -all第2章 C语言编程基础1.#include int main(void) printf(*n); 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 int main(void) int x,y; printf(please input x: n); scanf(%d,&x); if(x=1&x10) y=2*x-1; else y=3*x-8; printf(y = %d,y); return 0;4.#include int main(void) double f,c; int a; printf(please input the type number of Temp:n); printf(0 : Fahrenheit - 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 int main(void) int i,j,m,n; double a5;double b5; double s=0; for(i=0; i5; i+) scanf(%lf,&ai); for(j=0; j5; j+) bj=1.0/aj; for(m=0; m5; m+) printf(%f ,bm); for(n=0; n5; n+) s = s + bn; printf(n %f n,s); return 0;6.#include int main(void) 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;jmax) 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(n0) printf(n0, dataerror!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 int main() double a1000; double s=0; int i; int z; for(i=0;i+) if(!scanf(%lf,&ai) break; for(z=0;zi;z+) s = s + az; s=s/i; printf(%f,s);9.#include #include struct address char name30; int phone;int main(void) int m,n; char a30; struct address stu3; for(m=0; m3; m+) scanf(%s,&); scanf(%d,&stum.phone); scanf(%s,&a); for(n=0; n3; n+) if(!strcmp(a,) printf(%s,%dn,,stun.phone); return 0;10.#includenode *insert_node(node *head, node *item) /head != NULL node *p = head; node *q = NULL; /始终指向p之前的节点 while(p-data 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); /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 data ) head = head1 ; head-next = MergeRecursive(head1-next,head2); else head = 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-2.4.20-8/kernel/fork.c5. #vi /usr/src/linux-2.4.20-8/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 main() int i,j,k; for(i=1; i=4; i+) for(j=1; j=j) k=i+j; printf(%d+%d=%d ,i,j,k); 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 main() int num1,num2; printf(Input two numbers: ); scanf(%d %d,&num1,&num2); max(num1, num2);int max(int i, int j) if(ij) 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：phonyall : 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6章 文件I/O操作1. #ls -l filelist2. #pwd filelist3. #xxx 2 filelist4.#include #include #include #include #include #define FLAGS O_RDONLY /*定义flags：只读方式*/#define PATHNAME /usr/src/linux-2.4.20-8/init/main.cint 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 #include #include #include #include #include #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; /*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); 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 #include #include #include #define FLAGS O_RDWR /*定义flags：读写方式*/#define FILENAME filelistint 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 #include #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 #include #include #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); return 0;9.#include 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 int main(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 int main(void) printf(stdin is ); if(stdin-_flags & _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_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 #include int main(void) FILE *fp; if(fp = fopen(/root/install.log, r) = NULL) printf(fail to open!n); exit(1); /*出错退出*/ printf(open successfuly!n); fclose(fp); return 0;3.#include #include #define Src_File /home/zhangfan/hello#define Des_File /home/zhangfan/tmpint 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 = fopen(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 (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 #define File_path /home/zhangfan/tmpint 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 #define File_path /root/install.log.syslog int main(void)FILE *fp;char buf 1024;fp=fopen(File_path, r);fscanf(fp,%s,&buf);fclose(fp);printf(%sn,buf);return 0;第8章 进程控制1. #ps # ps -aux2. kill3.#include #include main()printf(The current process ID is %dn,getpid();4.#include #include #include int main (void)pid_t pid; /*此时仅有一个进程*/ if(pid=fork() 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 #include #include int main (void)int 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 the count is: %d, and the child is: %dn, getpid(), count, child); return 0;6.#include int main(void)printf(Hello, world!n); exit(0); printf(Hello, world again!n);7.#include int main(void) printf(nparent process, output beginn); printf(parent process, content in buffer); /*没有换行符n*/ _exit(0); 8.#include #include #include #include int main(void) pid_t pc,pr; if (pc = fork() 0) printf(error in fork!); exit(1); /* fork出错退出*/ else 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 #include int main(void) int status; if (status = system(date) 0) printf(system error!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 #include main()printf(The current process ID is %dn,getpgrp();第9章 信号1. #kill -l2.#include #include void SignHandler(int iSignNum) printf(Capture signal number:%dn,iSignNum); int main(void) signal(SIGQUIT,SignHandler); while(1) sleep(1); return 0;3.#include #include int main(void) signal(SIGQUIT,SIG_IGN); while(1) sleep(1); return 0;4.#include #include #include #include int g_iSeq=0;void SignHandlerNew(int iSignNo,siginfo_t *pInfo,void *pReserved) int iSeq=g_iSeq+; printf(%d Enter SignHandlerNew,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(SIGQUIT,&act,NULL); return 0;5.#include#include#include#include#includeint 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, 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 #include int main(void) printf(Hello, I like Linux C programs!n); if(raise(SIGABRT) = -1) printf(raise failed!n); exit(1); printf(Hello, I like Linux C programs,again!n); return 0;7.#include#include#includevoid SigHandler(int signo,siginfo_t *info,void *context) char *pMsg=(char*)info-si_value.sival_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); 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#includevoid handler()printf(Hello, I like Linux C programs!n);int main(void)int i;signal(SIGALRM,handler);alarm(3);for(i=1;i5;i+)printf(sleeping %d .n,i);sleep(1); return 0;9.#include #include #include #include int g_iSeq=0;void SignHandlerNew(int iSignNo,siginfo_t *pInfo,void *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; sigemptyset(&sigSet); sigaddset(&sigSet,SIGINT); sigprocmask(SIG_BLOCK,&sigSet,NULL); sigemptyset(&act.sa_mask); sigaction(SIGINT,&act,NULL); /*注册SIGINT信号*