fileio: add routine for portably yanking lines out of a FILE stream

Makefile

@@ -1,5 +1,5 @@
 PROG		= pkgconf${PROG_SUFFIX}
-SRCS		= main.c parse.c pkg.c bsdstubs.c getopt_long.c fragment.c argvsplit.c
+SRCS		= main.c parse.c pkg.c bsdstubs.c getopt_long.c fragment.c argvsplit.c fileio.c
 
 include buildsys.mk
 

fileio.c

@@ -0,0 +1,64 @@
+/*
+ * fileio.c
+ * File reading utilities
+ *
+ * Copyright (c) 2012 William Pitcock <nenolod@dereferenced.org>.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "pkg.h"
+#include "bsdstubs.h"
+
+char *
+pkg_fgetline(char *line, size_t size, FILE *stream)
+{
+	char *s = line;
+	char *end = line + size - 1;
+	int c = '\0', c2;
+
+	if (s == NULL)
+		return NULL;
+
+	while (s < end && (c = getc(stream)) != EOF)
+	{
+		if (c == '\n')
+		{
+			*s++ = c;
+			break;
+		}
+		else if (c == '\r')
+		{
+			*s++ = '\n';
+
+			if ((c2 = getc(stream)) == '\n')
+				break;
+
+			ungetc(c2, stream);
+			break;
+		}
+		else
+			*s++ = c;
+	}
+
+	*s = '\0';
+
+	if (c == EOF && (s == line || ferror(stream)))
+		return NULL;
+
+	return line;
+}

pkg.h

@@ -140,4 +140,7 @@ pkg_fragment_t *pkg_fragment_copy(pkg_fragment_t *head, pkg_fragment_t *base);
 void pkg_fragment_delete(pkg_fragment_t *node);
 bool pkg_fragment_exists(pkg_fragment_t *head, pkg_fragment_t *base);
 
+/* fileio.c */
+char *pkg_fgetline(char *line, size_t size, FILE *stream);
+
 #endif