UNIX Manual

Week 1

#include<stdio.h>

main(int argc,char *argv[])

{

int number,i,pid;

printf("enter number of process in chain\n");

scanf("%d",&number);

for(i=0;i<=number-1;i++)

{

pid=fork();

if(pid==0)

wait();

else

{

printf("i am%d child\n",i);

printf("my process id=%d\n",getpid());

printf("my parent process id=%d\n",getppid());

}

}

}

Output:

administrator@ubuntu:~/555$ cc chain.c

administrator@ubuntu:~/555$ ./a.out

enter number of process in chain

2

i am0 child

my process id=1657

my parent process id=1415

i am1 child

my process id=1657


i am1 child

my process id=1658


administrator@ubuntu:~/555$ ^C

administrator@ubuntu:~/555$

Week 2:

//enviroment list is usually is of the form "variable=string"

#include<stdio.h>

#include<stdlib.h>

main(argc,argv,envp)

int argc;

char *argv[];

char *envp[];

{

int i;

extern char **environ;

for(i=0;envp[i]!='\0';i++)

printf("%s\n",envp[i]);

exit(0);

}

Output :

[root@ttram home]# cc envp1.c -o environ1

[root@ttram home]# ./environ1

KDE_MULTIHEAD=false

SSH_AGENT_PID=1929

HOSTNAME=ttram

SHELL=/bin/bash

TERM=xterm

HISTSIZE=1000

GTK_RC_FILES=/etc/gtk/gtkrc:/root/.gtkrc:/root/.gtkrc-kde

GS_LIB=/root/.kde/share/fonts

QTDIR=/usr/lib/qt-3.1

USER=root

LS_COLORS=no=00:fi=00:di=00;34:ln=00;36:pi=40;33:so=00;35:bd=40;33;01:cd=40;33;01:or=01;05;37;41:mi=01;05;37;41:ex=00;32:*.cmd=00;32:*.exe=00;32:*.com=00;32:*.btm=00;32:*.bat=00;32:*.sh=00;32:*.csh=00;32:*.tar=00;31:*.tgz=00;31:*.arj=00;31:*.taz=00;31:*.lzh=00;31:*.zip=00;31:*.z=00;31:*.Z=00;31:*.gz=00;31:*.bz2=00;31:*.bz=00;31:*.tz=00;31:*.rpm=00;31:*.cpio=00;31:*.jpg=00;35:*.gif=00;35:*.bmp=00;35:*.xbm=00;35:*.xpm=00;35:*.png=00;35:*.tif=00;35:

SSH_AUTH_SOCK=/tmp/ssh-NMnf1861/agent.1861

SESSION_MANAGER=local/ttram:/tmp/.ICE-unix/2010

USERNAME=root

KONSOLE_DCOP=DCOPRef(konsole-2162,konsole)

MAIL=/var/spool/mail/root

DESKTOP_SESSION=default

PATH=/usr/kerberos/sbin:/usr/kerberos/bin:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/usr/X11R6/bin:/root/bin

KONSOLE_DCOP_SESSION=DCOPRef(konsole-2162,session-1)

INPUTRC=/etc/inputrc

PWD=/home MODIFIERS=@im=none

LANG=en_US.UTF-8

GDMSESSION=default

SSH_ASKPASS=/usr/libexec/openssh/gnome-ssh-askpass

HOME=/root

SHLVL=3

BASH_ENV=/root/.bashrc

LOGNAME=root

LESSOPEN=|/usr/bin/lesspipe.sh %s

DISPLAY=:0

G_BROKEN_FILENAMES=1

COLORTERM=

XAUTHORITY=/root/.Xauthority

_=./environ1

[root@ttram home]#

Week 3

#include<stdio.h>

#include<unistd.h>

#include<sys/stat.h>


{

struct stat status;

int choice;

mode_t file;

stat(argv[1],& status);

printf("1--> checking input type\n");

printf("2-->checking file permission\n");

printf("enter choice\n");

scanf("%d", &choice);

switch(choice)

{

case 1:if(S_ISDIR(status.st_mode))

{

printf("input is a directory\n");

}

else if(S_ISREG(status.st_mode))

{

printf("input is regular file\n");

}

break;

case 2:if(file=S_ISREG(status.st_mode))

{

printf("given file=%s\n",argv[1]);

if(status.st_mode & S_IREAD)

printf("file has read permission\n");

if(status.st_mode & S_IWRITE)

printf("file has write permission\n");

if(status.st_mode & S_IEXEC)

printf("file has execute permission\n");

}

else

{

printf("given input is not a file\n");

}

break;

default:printf("invalid input\n");

break;

}

}

Output:

//test is directory or file

administrator@ubuntu:~/555$ cc file.c

administrator@ubuntu:~/555$ ./a.out test

1--> checking input type

2-->checking file permission

enter choice

1

input is a directory




enter choice

2

given input is not a file

administrator@ubuntu:~/555$ ./a.out file.c



enter choice

1

input is regular file




enter choice

2

given file=file.c

file has read permission

file has write permission

administrator@ubuntu:~/555$ ./a.out a.out



enter choice

1





enter choice

2

given file=a.out



file has execute permission

week 4

mq1.c :

#include<stdio.h>

#include<fcntl.h>

#include<sys/ipc.h>

#include<sys/msg.h>

#include<string.h>

main()

{

int mid,len;

struct mymsg

{

long mtype;

char mtext[100];

}msg;

if((mid=msgget((key_t)250,IPC_CREAT|0666))<0)

printf("\n error");

printf("mypid=%d\n ",getpid());

printf("To exit from queue, give string as 'cseb' \n");

for(;;)

{

printf("Enter data : ");

fgets(msg.mtext,100,stdin);

msg.mtype=getpid();

msgsnd(mid,&msg,sizeof msg.mtext,0);

if((strcmp(msg.mtext,"cseb\n"))==0)

break;

}

}

Mq2.c:

#include<stdio.h>

#include<fcntl.h>

#include<sys/ipc.h>

#include<sys/msg.h>

#include<string.h>

main()

{

int mid,len;

struct mymsg

{

long mtype;

char mtext[100];

}msg;

if((mid=msgget((key_t)250,IPC_CREAT|0666))<0)

printf("\n error");

printf("mypid=%d\n",getpid());

printf("To exit from the queue, give data as 'cseb'\n");

for(;;)

{

printf("Enter data :: ");

fgets(msg.mtext,100,stdin);

msg.mtype=getpid();

msgsnd(mid,&msg,sizeof msg.mtext,0);


break;

}

}

Mq3.c:

#include<stdio.h>

#include<fcntl.h>

#include<sys/ipc.h>

#include<sys/msg.h>

#include<string.h>

main()

{

int mid,len,c=0;

struct mymsg

{

long mtype;

char mtext[100];

}msg;

mid=msgget((key_t)250,IPC_CREAT|0666);

for(;;)

{

if((len=msgrcv(mid,&msg,100,0,0))<0)

printf("\nerror");

printf("\nmessage from:%d ",msg.mtype);

fflush(stdout);

len=strlen(msg.mtext);

write(0,msg.mtext,len);


{

c++;

if(c==2)

break;

}

}

}

Output:

[root@merits new]# cc mq1.c -o 1

[root@merits new]# ./1

mypid=4816

To exit from queue, give string as 'cseb'

Enter data : hi

Enter data : me

Enter data : fine

Enter data : cseb



mypid=4823

To exit from the queue, give data as 'cseb'

Enter data :: me

Enter data :: true

Enter data :: cseb



message from:4816 hi

message from:4816 me

message from:4816 fine

message from:4816 cseb

message from:4823 me

message from:4823 true

message from:4823 cseb

week5

#include<stdio.h>

#include<sys/types.h>

#include<unistd.h>

main()

{ int filedes[2];

char wrbuff[128],rdbuff[128]="hello this is child";

pid_t pid;

int i=pipe(filedes);//creates pipe

if (i==0)

{

printf("Pipe is Successfully created\n");

}

else

{

perror("");

}

pid=fork();

if(pid==0)

{

//child process

printf("In child process====%d\n",getppid());

read(filedes[0],rdbuff,128);//reading from read-end of pipe

printf("Msg from parent is %s\n",rdbuff);

}

else

{

//parent process

printf("In parent process\npid=====%d\n",getpid());

printf("Enter msg:");

scanf(" %[^\n]",wrbuff);

write(filedes[1],wrbuff,128);//writing to the write-end of pipe

}

}

Output:

$ cc pip.c

$ ./a.out

In child process==3564

In parent process== 3564

Enter msg:

hello

Message from parent is hello

Week6:

#include<stdio.h>

#include<unistd.h>

#include<sys/stat.h>


{

struct stat status;

int choice;

mode_t file;

stat(argv[1],& status);

printf("1--> checking input type\n");

printf("2-->checking file permission\n");

printf("enter choice\n");

scanf("%d", &choice);

switch(choice)

{

case 1:if(S_ISDIR(status.st_mode))

{

printf("input is a directory\n");

}

else if(S_ISREG(status.st_mode))

{

printf("input is regular file\n");

}

break;

case 2:if(file=S_ISREG(status.st_mode))

{

printf("given file=%s\n",argv[1]);

if(status.st_mode & S_IREAD)

printf("file has read permission\n");

if(status.st_mode & S_IWRITE)

printf("file has write permission\n");

if(status.st_mode & S_IEXEC)

printf("file has execute permission\n");

}

else

{

printf("given input is not a file\n");

}

break;

default:printf("invalid input\n");

break;

}

}

Output:

//test is directory or file

administrator@ubuntu:~/555$ cc file.c




enter choice

1

input is a directory




enter choice

2

given input is not a file




enter choice

1





enter choice

2

given file=file.c






enter choice

1





enter choice

2

given file=a.out



file has execute permission*/

week 7:

semacq.c:

#include<stdio.h>

#include<sys/sem.h>

#include<stdlib.h>

#define MY_SEM_ID 111

int main()

int semid;

struct sembuf sb;

/* Get the semaphore with the id MY-SEM_ID*/

semid=semget(MY_SEM_ID,1,0);

if(semid>=0)

{

/*sb- sembuf struct variable*/

sb.sem_num=0;

sb.sem_op=-1;

sb.sem_flg=0;

printf("semacq: Attempting to acquire semphore %d \n",semid);

/*Acquire the semaphore*/

if(semop(semid,&sb,1)==-1)

{

printf("semacq: semop failed\n");

exit(-1);

}

printf("semacq: semaphore acquired %d\n",semid);

}

return 0;

}

output:

structure of sembuf

struct sembuf

{

unsigned short sem_num;

short sem_op;

short sem_flg;

};

[root@merits semaphores]# cc semacq.c

[root@merits semaphores]# ls

a.out semacq.c semacq.c~ semcreate.c sem_getting.c~

[root@merits semaphores]# ./a.out

semacq: Attempting to acquire semphore 1114145

semacq: semaphore acquired 1114145

[root@merits semaphores]# ipcs -s -i 1114145

Semaphore Array semid=1114145

uid=0 gid=0 cuid=0 cgid=0

mode=0666, access_perms=0666

nsems = 1

otime = Not set

ctime = Wed Mar 23 10:19:55 2011

semnum value ncount zcount pid

0 0 1 0 0

[root@merits semaphores]#

Semcrd.c :


#include<sys/ipc.h>

#include<sys/sem.h>


int main()

{

int semid,cnt;

/*Get the semaphore with the id MY_SEM_ID*/


if(semid>=0)

{

/*read the current semaphore count*/

cnt=semctl(semid,0,GETVAL);

if(cnt!=-1)

{

printf("\nsemcrd:current semaphore count %d\n",cnt);

}

}

return 0;

}

output:

[root@merits semaphores]# cc semcrd.c

semcrd.c: In function ‘main’:

semcrd.c:17: warning: incompatible implicit declaration of built-in function ‘printf’


semcrd:current semaphore count 1

[root@merits semaphores]# */

Semcreate.c :


#include<sys/ipc.h>

#include<sys/sem.h>


int main()

{

int semid;

/*create the semaphore with the id MY_SEM_ID*/

semid=semget(MY_SEM_ID,1,0666|IPC_CREAT);

if(semid>=0)

printf("semcreate: create a semphore %d\n",semid);

return 0;

}

output:

[root@merits semaphores]# cc semcreate.c

sem_create.c: In function ‘main’:

sem_create.c:11: warning: incompatible implicit declaration of built-in function ‘printf’


a.out semcreate.c


semcreate: create a semphore 1114145

[root@merits semaphores]#

Semrel.c

#include<stdio.h>

#include<sys/sem.h>

#include<stdlib.h>


int main()

{

int semid;

struct sembuf sb;



if(semid>=0)

{

printf("semrel: Releasing semphore %d\n",semid);

sb.sem_num=0;

sb.sem_op=1;

//releasing

sb.sem_flg=0;

}

/*Release the semaphore */

if(semop(semid,&sb,1)==-1)

{

printf("semrel:semaphore released %d\n",semid);

}

return 0;

}

output:

[root@merits semaphores]# cc semrel.c


semrel: Releasing semphore 1114145

(or)


semacq.c semcrd.c semcreate.c semrel.c semset.c semset.c~


semrel.c:30:3: warning: no newline at end of file





semcrd.c:17: warning: incompatible implicit declaration of built-in function ‘printf


























Semset.c


#include<sys/ipc.h>

#include<sys/sem.h>


int main()

{

int semid,ret;



if(semid>=0)

{

/*Read the current semaphore count */

ret=semctl(semid,0,SETVAL,6);

if(ret!=-1)

printf("semcrd: semaphore count updated : %d\n",ret);

}

return 0;

}

output:

[root@merits semaphores]# cc semacq.c


semacq: Attempting to acquire semphore 1114145

semacq: semaphore acquired 1114145


semcrd.c: In function ‘main’:semcrd.c:17: warning: incompatible implicit declaration of built-in function ‘printf’



[root@merits semaphores]# cc semset.c

semset.c: In function ‘main’:

semset.c:15: warning: incompatible implicit declaration of built-in function ‘printf’

semset.c:19:2: warning: no newline at end of file


semcrd: semaphore count updated : 0






week 8

shwrite.c

#include<stdio.h>

#include<sys/shm.h>

#include<string.h>

#define MY_SHM_ID 111

int main()

{

int shmid,ret;

void *mem;

//Get the shared memory segment using MY_SHM_ID

shmid=shmget(MY_SHM_ID,0,0);

mem=shmat(shmid,(const void *)0,0);

strcpy((char*)mem,"This is a test string\n");

ret=shmdt(mem);

return 0;

}

output:

[root@merits shared memory]# ls

a.out getpagesize.c sh sh1 shmattach.c shmcreate.c shmread.c

shmread.c~ shmsizeget.c shmwrite.c shmwrite.c~

[root@merits shared memory]# cc shmcreate.c -o sh

shmcreate.c:19:3: warning: no newline at end of file

[root@merits shared memory]# ./sh

Created a shared memory segment 786440

[root@merits shared memory]# cc shmwrite.c -o sh1

[root@merits shared memory]# ./sh1

Shread.c:

#include<stdio.h>

#include<sys/shm.h>

#include<string.h>


int main()

{

int shmid,ret;

void *mem;

//Get the shared memory segment using MY_SHM_ID


mem=shmat(shmid,(const void *)0,0);

printf("%s",(char *)mem);

ret=shmdt(mem);

return 0;

}

/*[root@merits shared memory]# ls

a.out getpagesize.c sh sh1 shmattach.c shmcreate.c shmread.c

shmread.c~ shmsizeget.c shmwrite.c shmwrite.c~

[root@merits shared memory]# cc shmcreate.c -o sh

shmcreate.c:19:3: warning: no newline at end of file

[root@merits shared memory]# ./sh


[root@merits shared memory]# cc shmwrite.c -o sh1


[root@merits shared memory]# cc shmread.c -o sh2


This is a test string

[root@merits shared memory]#

Shcreate.c

#include<stdio.h>

#include<sys/shm.h>


main()

{

int shmid;

/*create the shared memory segment using MY_SHM_ID*/

shmid=shmget(MY_SHM_ID,4096,0666|IPC_CREAT);

if(shmid>=0)

{

printf("Created a shared memory segment %d \n",shmid);

}

return 0;

}

OUTPUT:

[root@merits shared memory]# cc shmcreate.c

[root@merits shared memory]# ./a.out


[root@merits shared memory]# ipcs -m

------ Shared Memory Segments --------

key shmid owner perms bytes nattch status

0x00000002 65536 root 600 655360 2

0x0052e2c1 131073 postgres 600 28377088 2

0x0056a4d5 262146 root 660 384 2

0x00000000 524291 root 600 393216 2 dest

0x00000000 393220 root 600 393216 2 dest

0x00000000 425989 root 600 393216 2 dest

0x00000000 557062 root 600 393216 2 dest

0x0056a4d6 1441799 root 660 131072 1

0x0000006f 1474568 root 666 4096 0

[root@merits shared memory]# ipcs -i

ipcs: option requires an argument -- i

usage : ipcs -asmq -tclup

ipcs [-s -m -q] -i id

ipcs -h for help.

You have new mail in /var/spool/mail/root

[root@merits shared memory]# ipcs -m -i 1474568

Shared memory Segment shmid=1474568

uid=0 gid=0 cuid=0 cgid=0

mode=0666 access_perms=0666

bytes=4096 lpid=0 cpid=3648 nattch=0

att_time=Not set

det_time=Not set

change_time=Wed Mar 30 15:18:02 2011

[root@merits shared memory]# ipcrm -m [root@merits shared memory]#

cc shmdel.c

ipcrm: already removed id ([root@merits)

ipcrm: unknown argument: shared

usage: ipcrm [ [-q msqid] [-m shmid] [-s semid]

[-Q msgkey] [-M shmkey] [-S semkey] ... ]

[root@merits shared memory]# [root@merits shared memory]# ./a.out

bash: [root@merits: command not found

[root@merits shared memory]# Shared Memory segment removed

bash: Shared: command not found

[root@merits shared memory]# ipcrm -m 1474568

[root@merits shared memory]# ipcs -m -i 1474568

shmctl : Invalid argument

[root@merits shared memory]#

Shdel.c

#include<stdio.h>

#include<sys/shm.h>

#include<string.h>

#include<errno.h>


int main()

{

int shmid,ret;

/*create the shared memory segment using MY_SHM_ID*/


if(shmid>=0)

{

ret=shmctl(shmid,IPC_RMID,0);

if(ret==0)

printf("Shared Memory segment removed\n");

else

printf("shmctl failed (%d)\n",errno);

}//if

else

{

printf("shared memory segment not found\n");

return 0;

}

output:

[root@merits shared memory]# cc shmdel.c


Shared Memory segment removed

note: if u not including the shmget() fn. u get following error

[root@merits shared memory]# cc shmdel.c


shmctl failed (22)

Week 9:

TCPclient.c

#include<stdio.h>

#include<stdlib.h>


#include<netinet/in.h>

#include<errno.h>

#include<string.h>


{

int sockfd;

int nbytes,nbytes1;

struct sockaddr_in servaddr;

char buff[512],buff1[512];

if(argc!=3)

{

printf("use client servaddr servport");

exit(1);

}

if((sockfd=socket(AF_INET,SOCK_STREAM,0))<0)

{

perror("socket ");

exit(1);

}

servaddr.sin_family=AF_INET;

servaddr.sin_port=htons(atoi(argv[2]));

servaddr.sin_addr.s_addr=htonl(inet_addr(argv[1]));

if(connect(sockfd,(struct sockaddr*)&servaddr,sizeof(servaddr))<0)

{

perror("connect failed");

exit(1);

}

printf("\nconected ...\n");

while((nbytes=read(0,buff,512))>0)

{

if(write(sockfd,buff,nbytes)<0)

{

error("error");

exit(1);

}

if((nbytes1=read(sockfd,buff1,512))<0)

{

perror("read error");

exit(1);

}

if(write(1,buff1,nbytes1)<0)

{

perror("write error!");

exit(1);

}

printf("\n");

}

}

TCPserver.c


#include<sys/socket.h>

#include<errno.h>


#include<stdlib.h>

#include<stdio.h>

main(int argc, char *argv[])

{

int sockfd,nbytes,newfd;

char buff[512];

struct sockaddr_in myaddr;

if((sockfd=socket(AF_INET,SOCK_STREAM,0))<0)

{

perror("Socket is failed to connect");

exit(1);

}

myaddr.sin_family=AF_INET;

myaddr.sin_port= htons(atoi(argv[1]));

myaddr.sin_addr.s_addr=htonl(INADDR_ANY);

if((bind(sockfd,(struct sockaddr *)&myaddr,sizeof(myaddr)))<0)

{

perror("Binding is failed");

exit(1);

}

if(listen(sockfd,5)<0)

{

perror("Listen fail");

exit(1);

}

printf("\nwaiting for connection.......\n");

if((newfd=accept(sockfd,0,0))<0)

{

perror("Accept failed");

exit(1);

}

while((nbytes=read(newfd,buff,512))>0)

{

write(1,buff,nbytes);

if(write(newfd,buff,nbytes)<0)

{

perror("Write error");

exit(1);

}

}

}

output :

//FIRST START THE SERVER

[ttram@ttram tcpecho]$ ls

tcpechoclient.c tcpserver.c

[ttram@ttram tcpecho]$ cc tcpserver.c

[ttram@ttram tcpecho]$ ./a.out 2356

waiting for connection.......

hi

hello

i am fine

okd

bye

[ttram@ttram tcpecho]$

//THEN CLIENT

[ttram@ttram TCP AND UDP]$ cd tcpecho/

[ttram@ttram tcpecho]$ ls

a.out tcpechoclient.c tcpserver.c

[ttram@ttram tcpecho]$ cc tcpechoclient.c -o cli

[ttram@ttram tcpecho]$ ./cli 0.0.0.0 2356

conected ...

hi

hi

hello

hello

i am fine

i am fine

okd

okd

bye

bye

^C

[ttram@ttram tcpecho]$

Week 10:

Udpclient:




#include<errno.h>

#include<stdlib.h>

#include<stdio.h>

#include<string.h>


{

int sockfd,nbytes,nbytes1,addrlen;

char buff[512];

struct sockaddr_in myaddr,servaddr;

if(argc!=3)

{

perror("usage client,serverport,serveraddress");

exit(1);

}

if((sockfd=socket(AF_INET,SOCK_DGRAM,0))<0)

{

perror("Socket failed");

exit(1);

}


myaddr.sin_port=htons(0);

myaddr.sin_addr.s_addr=htonl(0l);

if((bind(sockfd ,(struct sockaddr*)&myaddr,sizeof(myaddr)))<0)

{

perror("bind failed");

exit(1);

}

while(1)

{

printf("\n Enter data '#' to exit ::\n");

if((nbytes=read(0,buff,512))<0)

{

perror("read error");

exit(1);

}

servaddr.sin_family=AF_INET;

servaddr.sin_port=htons(atoi(argv[2]));

servaddr.sin_addr.s_addr=htonl(inet_addr(argv[1]));

if((sendto(sockfd,buff,nbytes,0,(struct sockaddr*)&servaddr,sizeof(servaddr)))<0)

{

perror("send to failed");

exit(1);

}

if(buff[0]=='#')

break;

printf("\nEchoed data read ::\n");

addrlen=sizeof(servaddr);

if((nbytes1=recvfrom(sockfd,buff,512,0,(struct sockaddr*)&servaddr,&addrlen))<0)

{

perror("recvfrom error");

exit(1);

}

write(1,buff,nbytes1);

bzero(buff,nbytes);

}

}

Udpserver:




#include<errno.h>

#include<stdio.h>

#include<stdlib.h>

#include<string.h>


{

int sockfd,addrlen,nbytes,tt;

char buffer[512],buff[512];

struct sockaddr_in myaddr,clntaddr;

if(argc!=2)

{

perror("usage server port");

exit(1);

}

if((sockfd=socket(AF_INET,SOCK_DGRAM,0))<0)

{

perror("Socket failed");

exit(1);

}


myaddr.sin_port=htons(atoi(argv[1]));

myaddr.sin_addr.s_addr=htonl(0l);

if((bind(sockfd,(struct sockaddr*)&myaddr,sizeof(myaddr)))<0)

{

perror("bind failed");

exit(1);

}

while(1)

{

addrlen=sizeof(clntaddr);

if((nbytes=recvfrom(sockfd,buff,512,0,(struct sockaddr*)&clntaddr,&addrlen))<0)

{

perror("recvfrom error");

exit(1);

}

if(buff[0]=='#')

break;

write(1,buff,nbytes);

if((sendto(sockfd,buff,nbytes,0,(struct sockaddr*)&clntaddr,addrlen))<0)

{

perror("send to error");

exit(1);

}

bzero(buff,nbytes);

}

}

output :

/HERE ALSO FIRST START THE SERVER WITH A PORT

[ttram@ttram udpecho]$ cc udpser.c -o ser

[ttram@ttram udpecho]$ ./ser 4532

hi

fine

good

[ttram@ttram udpecho]$

//NEXT CLIENT

[ttram@ttram udpecho]$ cc udpcli.c -o cli

[ttram@ttram udpecho]$ ./cli 0.0.0.0 4532

Enter data '#' to exit ::

hi

Echoed data read ::

hi


fine

Echoed data read ::

fine


good

Echoed data read ::

good

Enter data '#' to exit ::#

[ttram@ttram udpecho]$

Documents

UNIX Manual