Program using libvarnam that transliterates string literals

mlpython.c

/*
Usage : ./a.out <pythonfile>
The transliterated file will be saved as original filename + ml.py
Remember to place the file in the examples subdir in the libvarnam codebase
wont work for multiple literals in the same line
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <malloc.h>
#include "../varnam.h"

#define buffer_size 300

void get_transliteration_output(varray *words,char* newword)
{
	int i;
	vword *word;
	word = varray_get(words,i);
	strcpy(newword,word->text);
}

void make_newline(char *line,char *start,char *stop,char *newword,char *newline)
{
	int i;
	char *ptr;
	
	//Copying everything till " to newline
	for(i=0,ptr=line;ptr!=start;ptr++,i++)
	{
		newline[i]=line[i];
	}

	//concatenating the malayalam pattern
	strcat(newline,newword);
	strcat(newline,"\"");
	strcat(newline,stop);
	//printf("%s",newline);
	
}
int main(int argc,char *argv[])
{
	FILE *source,*target;
	char *source_file,*ptr,*error_msg,*start,*stop,*newword,*newline;

	varnam *handle;
	varray *words;
	int rc;

	rc=varnam_init_from_lang("ml",&handle,&error_msg);

	if(rc!=VARNAM_SUCCESS)
	{
		printf("Initialization failed : %s",error_msg);
		free(error_msg);
		return 1;
	}

	source_file=argv[1];
	source=fopen(source_file,"r");	

	//Finding the . to extract the filename
	ptr=strstr(source_file,".");
	*ptr='\0';
	
	//source_file does not have the '.py' extension now since we placed a '\0' there
	target=fopen(strcat(source_file,"ml.py"),"w");

	char line[200];

	fprintf(target,"#!usr/bin/python\n");
	fprintf(target,"# -*- coding: UTF-8 -*-\n");

	while(fgets(line,sizeof(line),source))
	{	

		start=strstr(line,"\"");
		if(start)
		{}
			start+=1;
			stop=strstr(start,"\"");
			//Assuming that there is a matching ". 
			*stop='\0';
			stop+=1;
	
			rc=varnam_transliterate(handle,start,&words);

			newword=(char*)malloc(buffer_size);
			newline=(char*)malloc(buffer_size);
			
			get_transliteration_output(words,newword);
			make_newline(line,start,stop,newword,newline);
			printf("Transliterated line : %s",newline);
			
			fprintf(target,"%s",newline);
			free(newword);
			free(newline);			
		}
		else
			fprintf(target,"%s",line);
	}


}