Counting Lines

ej25 · 12-03-2004, 02:16 AM

Code:

u=1;
printf("%i: ",u);
	u++;
	while ((n=read(fd1, buffer, SIZE)) != 0) {
		int i;
		
		for (i=0; i<n ; i++){
		
		if(buffer[i] == '\n' && buffer[i+1]== 0 )
                        write(1,&buffer[i],sizeof(char));
		
		else if(buffer[i] == '\n' ){
                
                         write(1,&buffer[i],sizeof(char));
 		buffer2[1]=u
                          write(1,&buffer2[i],sizeof(char));
		u++;
		}
				
		else
		 write(1,&buffer[i],sizeof(char));

		 }

I'm trying in this code to read a file and display it using stdout with numbering each line in the file, but there is somthing wrong with the numbering. I don't what's it. Any help, please?

salparadise · 12-03-2004, 02:59 AM

try respelling counting for a start (in the post subject line)

ej25 · 12-03-2004, 03:08 AM

Sorry, it's typing mistake

ej25 · 12-03-2004, 05:39 AM

29? NO body said something!!!!!!!!!!!

okmyx · 12-03-2004, 06:03 AM

I'm no expert and its a long time since i've done any coding.

To my knowledge most programming languages have the ability to read individual lines from a file so this would remove the need to do all that \n checking

pseudo code:

linenum = 1;
while not fromfile.EOF {
stdout.write( linenum + ":" + readline(fromfile) );
linenum=linenum+1;
}

Hko · 12-03-2004, 06:51 AM

It would be significantly easier if you use the stdio functions instead of the low-level read(). That way it would be quite straight-forward to implement okmyx' pseudo code.

AnanthaP · 12-03-2004, 06:57 AM

why a program? Why not use `awk` thus:

awk '{print r++; $0}' <MyFileName>

End

Hko · 12-03-2004, 07:09 AM

Quote:

Originally posted by AnanthaP
why a program? Why not use `awk` thus:

awk '{print r++; $0}' <MyFileName>

Maybe because it's homework.

BTW awk is also oversized for this:

Code:

grep -n '' file.txt

There even is a standard tool to do just this:

Code:

nl file.txt

perfect_circle · 12-03-2004, 08:00 AM

Quote:

u=1;
printf("%i: ",u);
u++;
while ((n=read(fd1, buffer, SIZE)) != 0) {
int i;

for (i=0; i<n ; i++){

if(buffer[i] == '\n' && buffer[i+1]== 0 )
write(1,&buffer[i],sizeof(char));

else if(buffer[i] == '\n' ){

write(1,&buffer[i],sizeof(char));
buffer2[1]=u; <- use sprintf if you want to output the number u contains into buffer2 (if buffer2 is a char array)
write(1,&buffer2[i],strlen(buffer2)*sizeof(char)+1);
u++;
}

else
write(1,&buffer[i],sizeof(char));

}

ej25 · 12-04-2004, 01:13 AM

I did what you said perfect_circle.
but it give me symbols rather than number,why?!!!

perfect_circle · 12-04-2004, 04:51 AM

post the whole program and the output

ej25 · 12-04-2004, 11:47 AM

Code:

int fd1;
	char buffer2[SIZE];
	char buffer[SIZE];

fd1 = open(argv[c2], O_RDONLY);            
	u=1;
	if (fd1 == -1) {

		fprintf(stderr, "Cannot open file %s\n", argv[c2]);

		return 2;
	}
	 
	/* display the file */

	printf("\nThe contents of the %s file:\n",argv[c2]);	
	printf("%i: ",u);
	u++;
	while ((n=read(fd1, buffer, SIZE)) != 0) {
		int i;
		buffer2[1]=u;
	
		for (i=0; i<n ; i++){
		
		if(buffer[i] == '\n' && buffer[i+1]== 0 )
		write(1,&buffer[i],sizeof(char));
		
		else if(buffer[i] == '\n' ){
		write(1,&buffer[i],sizeof(char));
                write(1,&buffer2[1],strlen(buffer2)*sizeof(char)+1);
		u++;
		}
				
		else
		 write(1,&buffer[i],sizeof(char));
		 }

this the output:

Code:

The contents of the p2.c file:
 
#include <stdio.h>
#include<string.h>

#include <unistd.h>


#include <stdlib.h>


#include <sys/wait.h>


 

main (int argc, char *argv[] ){


        int i;

        int status;

        int c=1;

    int  forkresult ;

    char array[20];

char line[80];
char *num, *count,*begin;    
  


fgets(line, 80, stdin); 

    forkresult = fork ( ) ;


         

    if (forkresult != 0)


       /* the parent will execute this code */


             wait(&status);
  
     

       


        else    /* forkresult == 0 */
7
7 
7              
7               /* the child will execute this code */
7
7
7
7               num=line;
7               begin=line;
7               count=array;
7               line[strlen(line)]==' ';
7               for(num;*num<strlen(line);num++){
7               if(line[(int)num]==' '){
7               array[(int)count]=(int)malloc((num-begin)+1);
7               strncpy(&array[(int)count],&line[(int)begin],(int)begin-strlen(line));
7               begin=num+1;
7               count++;
7               }
7}
7               array[(int)count]=NULL;
7
7           
7            /*execvp (argv[1],&argv[1] );
7
7*/
7              
7     execvp (array, NULL);
R
R
R
R                printf ("EXEC Failed\n") ; 
R  
R      /* This above line will be printed only on error and not otherwise */ 
R
R      
R             exit (1) ;
R
R
R}
R

perfect_circle · 12-04-2004, 01:31 PM

I told u to use sprintf!!!!!
Something like:
sprintf(buffer2,"%d",u)

do
man sprintf
for more details

ej25 · 12-05-2004, 02:06 AM

Quote:

display it using stdout

I do it before using putchar() and it work fine but know I want to use the stdout

Quote:

write(1,&buffer[i],sizeof(char));

So is there something wrong with what I do in the code, please tell me?

perfect_circle · 12-05-2004, 03:20 AM

Quote:

write(1,&buffer[i],sizeof(char));

I think you are using write wrong.

Try

Code:

write(1,buffer[i],sizeof(char));

You don't need the &.
buffer is a pointer, you should pass the value of buffer and not the address