Exiv2

#include <stdio.h>

#include <string.h>

static enum

{	errorOK = 0

, 	errorSyntax 

,   errorProcessing

} error = errorOK ;

void syntax()

{

	printf("syntax: dmpf [-option]+ filename\n") ;

}

bool printable(unsigned char c) { return c >= 32 && c <= 127 && c != '.' ; } 

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

{

	char* filename = argv[1] ;

	FILE* f = NULL ;

//  GCC_PREFIX_HEADER = dmpf.pch

//	GCC_PRECOMPILE_PREFIX_HEADER = YES

//	printf("engineer = %s\n",ENGINEER) ; // compiled in by dmpf.pch

	if ( argc < 2 ) {

		syntax() ;

		error = errorSyntax ;

	}

	if ( !error ) {

		f = strcmp(filename,"-") ? fopen(filename,"rb") : stdin ;

		if ( !f ) {

			printf("unable to open file %s\n",filename) ;

			error = errorProcessing ;

		}

	}

	if ( !error  )

	{

		char line[1000] ;

		char buff[16]   ;

		int  n          ;

		int count = 0   ;

		while ( (n = fread(buff,1,sizeof buff,f)) > 0 )

		{

			// line number

			int l = sprintf(line,"%#6x %6d: ",count,count ) ;

			count += n ;

			// ascii print

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

			{

				char c = buff[i] ;

		        l += sprintf(line+l,"%c", printable(c) ? c : '.' ) ;

			}

			// blank pad the ascii

			int save = n ;

			while ( n++ < sizeof(buff) ) l += sprintf(line+l," ") ;

			n = save     ;

		    // hex code

		    l += sprintf(line+l,"  -> ") ;

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

			{

				unsigned char c = buff[i] ;

				l += sprintf(line+l,printable(c) ? "  %c" : " %02x" ,c) ;

			}

			line[l] = 0 ;

			printf("%s\n",line) ;

		}

	}

	return error ;

}