Thread: 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.

Code:

#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,"r");
    if(stream ==NULL)
    {
        printf("Enter a valid parameter.Program will exit.\n");
        exit(1);
    }

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

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

         }

    return 0;  // 0 is success
}

anybody can suggest something better or help solve it?

i changed the code into this.now the characters that will be printed are passed through command line via argv, but i still do something wrong.help guys

Code:

#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,k,m=0, n = 0;
    char   *alpha;
	alpha=argv[1];
    filename =argv[2];
    stream=fopen(filename,"r");

    if(stream ==NULL)
    {
        printf("Enter a valid parameter.Program will exit.\n");
        exit(1);
    }

    while ( (code[n]=get_line(stream)) != NULL ) {
        n++;
    }
while((k=getc(alpha))!='\0')
	{
		m++;
	}
	printf("%d\n",m);
    for ( i = 0 ; i < n ; i++ )
	    {
         for(j=0;j<m;j++)
			 {
			 loc=strchr(code[i],alpha[j]);
			 if (loc!=NULL){
				 printf("%s",alpha[j]);
				           }
			 }

         }

    return 0;  // 0 is success
}

somebody help guys

> while((k=getc(alpha))!='\0')
This doesn't even compile - or you're ignoring a serious warning. alpha is a char*, and getc expects a FILE*

Besides, it looks like you should be doing
m = strlen( alpha );

> printf("%s",alpha[j]);
To print a single character, its
printf("%c",alpha[j]);