Minor code reorganization, handled tab characters correctly

src/include/io.h

@@ -0,0 +1,29 @@
+/*
+   ncdg - A program to help generate natechoe.dev
+   Copyright (C) 2022  Nate Choe (natechoe9@gmail.com)
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <stdio.h>
+
+struct linefile {
+	char *prevline;
+	FILE *file;
+};
+
+void ungetline(struct linefile *file, char *line);
+char *getline(struct linefile *file);
+struct linefile *newlinefile(FILE *file);
+void freelinefile(struct linefile *file);

src/io.c

@@ -0,0 +1,83 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <io.h>
+
+static char *append(char *str, char c, size_t *len, size_t *alloc);
+
+void ungetline(struct linefile *file, char *line) {
+	file->prevline = line;
+}
+
+char *getline(struct linefile *file) {
+	size_t alloc;
+	size_t len;
+	char *ret;
+	int c;
+
+	if (file->prevline != NULL) {
+		ret = file->prevline;
+		file->prevline = NULL;
+		return ret;
+	}
+
+	c = fgetc(file->file);
+	if (c == EOF)
+		return NULL;
+	ungetc(c, file->file);
+
+	alloc = 80;
+	len = 0;
+	ret = malloc(alloc);
+	if (ret == NULL)
+		return NULL;
+
+	for (;;) {
+		c = fgetc(file->file);
+		if (c == '\n') {
+			ret[len] = '\0';
+			return ret;
+		}
+		if (c == '\t') {
+			while (len % 4 != 0) {
+				ret = append(ret, ' ', &len, &alloc);
+				if (ret == NULL)
+					return NULL;
+			}
+		}
+		else {
+			ret = append(ret, c, &len, &alloc);
+			if (ret == NULL)
+				return NULL;
+		}
+	}
+}
+
+struct linefile *newlinefile(FILE *file) {
+	struct linefile *ret;
+	ret = malloc(sizeof *ret);
+	ret->prevline = NULL;
+	ret->file = file;
+	return ret;
+}
+
+void freelinefile(struct linefile *file) {
+	free(file->prevline);
+	fclose(file->file);
+	free(file);
+}
+
+static char *append(char *str, char c, size_t *len, size_t *alloc) {
+	if (*len >= *alloc) {
+		char *newstr;
+		*alloc *= 2;
+		newstr = realloc(str, *alloc);
+		if (newstr == NULL) {
+			free(str);
+			return NULL;
+		}
+		str = newstr;
+	}
+	str[(*len)++] = c;
+	return str;
+}

src/template.c

@@ -20,13 +20,9 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include <io.h>
 #include <template.h>
 
-struct linefile {
-	char *prevline;
-	FILE *file;
-};
-
 enum paratype {
 	NORMAL,
 	EMPTY,
@@ -85,16 +81,13 @@ static int writeescape(char c, FILE *outfile);
 static int writedata(char *data, size_t len, FILE *outfile);
 static int writesimple(char *data, size_t len, FILE *outfile);
 
-static void ungetline(struct linefile *file, char *line);
-static char *getline(struct linefile *file);
-
 static const char *escapedchars = "!\"#%&'()*,./:;?@[\\]^{|}~";
 
 int parsetemplate(FILE *infile, FILE *outfile) {
-	struct linefile realin;
-	realin.prevline = NULL;
-	realin.file = infile;
-	while (parsepara(&realin, outfile) == 0) ;
+	struct linefile *realin;
+	realin = newlinefile(infile);
+	while (parsepara(realin, outfile) == 0) ;
+	freelinefile(realin);
 
 	return 0;
 }
@@ -531,50 +524,3 @@ static int writesimple(char *data, size_t len, FILE *outfile) {
 	}
 	return 0;
 }
-
-static void ungetline(struct linefile *file, char *line) {
-	file->prevline = line;
-}
-
-static char *getline(struct linefile *file) {
-	size_t alloc;
-	size_t len;
-	char *ret;
-	int c;
-
-	if (file->prevline != NULL) {
-		ret = file->prevline;
-		file->prevline = NULL;
-		return ret;
-	}
-
-	c = fgetc(file->file);
-	if (c == EOF)
-		return NULL;
-	ungetc(c, file->file);
-
-	alloc = 80;
-	len = 0;
-	ret = malloc(alloc);
-	if (ret == NULL)
-		return NULL;
-
-	for (;;) {
-		if (len >= alloc) {
-			char *newret;
-			alloc *= 2;
-			newret = realloc(ret, alloc);
-			if (newret == NULL) {
-				free(ret);
-				return NULL;
-			}
-			ret = newret;
-		}
-		c = fgetc(file->file);
-		if (c == '\n') {
-			ret[len] = '\0';
-			return ret;
-		}
-		ret[len++] = c;
-	}
-}