txt_to_tex.c

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

#define LINESIZE 256

int main(int argc, char **argv){
	printf("\\documentclass{article}\n\n");
	
	char author[64];
	char title[64];
	fgets(author, 64, stdin);
	fgets(title, 64, stdin);
	*strchr(author, '\n') = '\0';
	*strchr(title, '\n') = '\0';
	
	printf("\\author{%s}\n\\title{%s}\n\\date{}\n\n", author, title);
	printf("\\usepackage{dropping}\n\n");
	printf("\\begin{document}\n\\maketitle\n");
	
	char *line = calloc(LINESIZE, sizeof(char));
	while(fgets(line, LINESIZE, stdin)){
		if(!*line || *line == '\n')
			continue;
		
		else if(isdigit(*line)){
			int n;
			sscanf(line, "%d", &n);
			printf("\\section*{Chapter %d}\n", n);
		}

		else if(*line && isspace(*line))
			printf("\n%s", line);

		else
			printf("%s", line);
	}
	
	printf("\\end{document}\n");
	return 0;
}