split i/o stuff out to io.c

1 files changed, 71 insertions, 0 deletions

diff --git a/io.c b/io.c
new file mode 100644
index 0000000..0aab2ff
--- /dev/null
+++ b/io.c
@@ -0,0 +1,71 @@
+#define _XOPEN_SOURCE 700
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+//#include <unistd.h>
+
+#include "more.h"
+
+ssize_t more_getline(struct more_file *mf, size_t lineno)
+{
+	if (mf->nlines <= lineno && mf->nlines != 0) {
+		fsetpos(mf->f, &(mf->lines[mf->nlines - 1]));
+		getline(&(mf->buf), &(mf->nbuf), mf->f);
+	}
+
+	while (mf->nlines <= lineno) {
+		mf->nlines++;
+		mf->lines = realloc(mf->lines, mf->nlines * sizeof(*mf->lines));
+
+		fgetpos(mf->f, &(mf->lines[mf->nlines - 1]));
+
+		getline(&(mf->buf), &(mf->nbuf), mf->f);
+
+		if (mf->backing != mf->f) {
+			fgetpos(mf->backing, &(mf->lines[mf->nlines - 1]));
+			fputs(mf->buf, mf->backing);
+		}
+	}
+
+	fsetpos(mf->backing, &(mf->lines[lineno]));
+	return getline(&(mf->buf), &(mf->nbuf), mf->backing);
+}
+
+struct more_file more_open(const char *path)
+{
+	struct more_file mf = {
+		.f = stdin,
+	};
+
+	if (strcmp(path, "-")) {
+		mf.f = fopen(path, "r");
+		if (!mf.f) {
+			fprintf(stderr, "more: %s: %s\n", path, strerror(errno));
+			return mf;
+		}
+	}
+
+	fpos_t pos;
+	if (fgetpos(mf.f, &pos) != 0) {
+		mf.backing = tmpfile();
+	} else {
+		mf.backing = mf.f;
+	}
+
+	return mf;
+}
+
+void more_close(struct more_file *mf)
+{
+	if (mf->backing != mf->f) {
+		fclose(mf->backing);
+	}
+
+	if (mf->f != stdin) {
+		fclose(mf->f);
+	}
+
+	free(mf->lines);
+	free(mf->buf);
+}