Thread: line reading problem

am posting this code again.i changed this code to read a file and write out the first line, and all non blanks lines preceded by a blank line.

Code:

/*This program reads a file given as command line argument
and writes out the first lines and all(non blank) lines 
preceded by a blank line.
*/

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
typedef char * STRNG;

STRNG code[80];

STRNG get_line(FILE * inf) {/*Start of the function which reads one line*/
    STRNG s = NULL;
    int count = 0;
    int tok;            // must be int - EOF is an int, not a char

    while ( (tok=getc(inf)) != EOF && tok != '\n' ) {
        if ( s == NULL ) s = malloc( 80 );
        s[count++] = tok;
    }
    if ( tok != EOF ) {
        if ( s == NULL ) s = malloc( 80 );  // possibly a newline on its own
        s[count++] = tok;                   // append the \n
        s[count] = '\0';
    }
    return s;
}

int main(int argc, char *argv[]) {
    char    *filename;
    FILE    *stream;
    int     i,c, n = 0;

    filename =argv[1];
    stream=fopen(filename,"r");
    if(stream ==NULL)
    {
        printf("Enter a valid parameter.Program will exit.\n");
        exit(1);
    }
    code[n]=get_line(stream);
	printf("%s",code[n]);
    while ( (code[n]=get_line(stream))!= NULL)
	    {

                      if(strlen(code[n])==1)/*here is the problem*/
                        {
	         printf("%s\n",code[n+1]);
                        }

    }




    return 0;  // 0 is success
}

the programs recognises the blank lines but it prints out only <null>

> the programs recognises the blank lines but it prints out only <null>
Yeah, so?

> printf("%s\n",code[n+1]);
But you haven't read in code[n+1] yet, so trying to print it will fail.

Tip:
Read the whole file in using the while loop I showed you earlier.

Then use a for ( i = 0 ; i < n ; i++ )
to scan the array, and output lines according to your rules.

thanks again Salem. sometimes am realy stupid.