comparing chars with pointer to cha

[papous]

comparing chars with pointer to char
the code below is suppose to read from a file and to print out all alphanumeric characters(a-z,A-Z,0-0) spaces and newlines, throwing away the rest.

#include<stdio.h>
#include<stdlib.h>
#include<string.h>

typedef char * STRNG;

STRNG code[80];

STRNG get_line(FILE * inf) {
    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;
	char    *loc;
    FILE    *stream;
    int     i,j, n = 0;            // Moved C++ declaration
    char  alpha[64]={'q','w','e','r','t','y','u','i','o','p'
,'a','s','d','f','g','h','j','k','l','m','n',
 	'b','v','c','x','z','Q','W','E','R','T','Y','U','
 I','O','P','L','K','J','H','G','F','D','S','A','Z'
,
 	'X','C','V','B','N','M','1','2','3','4','5','6','
7','8','9','0',' ','\n'};

    filename =argv[1];
    stream=fopen(filename,&quot;r&quot;);
    if(stream ==NULL)
    {
        printf(&quot;Enter a valid parameter.Program will exit.\n&quot;);
        exit(1);
    }

    while ( (code[n]=get_line(stream)) != NULL ) {
        n++;
    }

    printf( &quot;%d lines found\n&quot;, n );
    for ( i = 0 ; i < n ; i++ )
	    {
         for(j=0;j<64;j++)
			 {
			 loc=strstr(code[i],alpha[j]);
			 if (loc!=NULL){
				 printf(&quot;%s&quot;,alpha[j]);
				           }
			 }

         }

    return 0;  // 0 is success
}

anybody can suggest something better or help solve it?

 

[irfin]

I think this simple code will does the same thing (get character [A-Z|a-z|0-9|' '|'\n'].

#include <stdio.h>
#include <conio.h>

FILE *fin; // filename for input file.
int ch; // variable to hold a character being read.


/**
* This program uses command line argument. It needs only
* one argument that is, the input file.
*/

int main(int argc, char **argv)
{
clrscr();
if (argc < 2) {
puts(&quot;usage: program_file input_file&quot;
puts(&quot;Try again.&quot;
return 1;
}

if ( (fin = fopen(argv[1], &quot;r&quot) == NULL ) {
printf(&quot;Error while opening file: %s \n&quot;, argv[1]);
return 1;
}

while ( (ch = getc(fin)) != EOF )
{
if ((ch>='A' && ch<='Z')||(ch>='a' && ch<='z') ||
(ch>='0' && ch<='9')||(ch==' ')||(ch=='\n'))
putchar(ch);
}

return 0;
}

/** Thank you **/

 

[smaniraja]

Hi, in ur way...

#include<stdio.h>
#include<stdlib.h>
#include<string.h>

typedef char * STRNG;
STRNG code[80];
STRNG get_line(FILE * inf)
{
STRNG s = NULL;
int count = 0;
int tok; // must be int - EOF is an int, not a char

s = malloc( 80 ); // add code for error checking
while ( (tok=getc(inf)) != EOF && tok != '\n' && count < 80 ) //otherwise memory overwrite may occur
{
if( (tok >= 48 && tok <= 57) || (tok >= 65 && tok <= 90) || (tok >= 97 && tok <= 122)) // ascii values of 0 -9, A -Z and a - z
s[count++] = tok;
}
return s;
}

int main(int argc, char *argv[]) {
char *filename;
char *loc;
FILE *stream;
int i,j, n = 0; // Moved C++ declaration

// check the number of command line argument
filename =argv[1];
stream=fopen(filename,&quot;r&quot;
if(stream ==NULL)
{
printf(&quot;Enter a valid parameter.Program will exit.\n&quot;
exit(1);
}

while ( (code[n]=get_line(stream)) != EOF ) {
n++;
}
fclose(stream);
printf( &quot;%d lines found\n&quot;, n );
for ( i = 0 ; i < n ; i++ )
{
printf(&quot;%s&quot;,code);
free(code) // the dynamically allocated memory shold be deallocated.
}
return 0; // 0 is success
}