Add missing common.c

1 files changed, 31 insertions, 0 deletions

diff --git a/common.c b/common.c
new file mode 100644
index 0000000..96c9b72
--- /dev/null
+++ b/common.c
@@ -0,0 +1,31 @@
+#include <stdio.h>
+#include <stddef.h>
+#include <string.h>
+
+void
+indicate_file_area(FILE* fd, size_t line, size_t column, size_t span) {
+	char margin[] = "  ";
+	/* FIXME use proper line counting, not this hack */
+	char buf[1024];
+	rewind(fd);
+	for (; line; line--) {
+		fgets(buf, sizeof(buf), fd);
+	}
+
+	fputs(margin, stderr);
+	fputs(buf, stderr);
+
+	/* corner case (still needed?) - buf was just return */
+	if (strlen(buf) == 1 && buf[0] == '\n') {
+		fputc('\n', stderr);
+	}
+
+	fputs(margin, stderr);
+	for (column--; column; column--) {
+		fputc(' ', stderr);
+	}
+	for (; span; span--) {
+		fputc('^', stderr);
+	}
+	fputc('\n', stderr);
+}