bshell: add line-editor and file-based input support

bshell/file.c

@@ -0,0 +1,116 @@
+#include "file.h"
+
+#include "line-source.h"
+
+#include <errno.h>
+#include <fx/collections/array.h>
+#include <fx/string.h>
+#include <stdlib.h>
+#include <string.h>
+
+static enum bshell_status get_name(
+	struct line_source *src,
+	char *buf,
+	size_t count,
+	size_t *nr_read)
+{
+	struct file *f = (struct file *)src;
+	*nr_read = snprintf(buf, count, "%s", f->f_path);
+	return BSHELL_SUCCESS;
+}
+
+static enum bshell_status get_row(
+	struct line_source *src,
+	size_t row,
+	char *buf,
+	size_t count,
+	size_t *nr_read)
+{
+	struct file *f = (struct file *)src;
+	size_t nr_rows = fx_array_size(f->f_lines);
+
+	if (row > nr_rows) {
+		return BSHELL_ERR_EOF;
+	}
+
+	fx_string *line = fx_array_at(f->f_lines, row - 1);
+
+	const char *line_str = fx_string_get_cstr(line);
+	size_t line_len = fx_string_get_size(line, FX_STRLEN_NORMAL);
+	size_t copy_len = fx_min(ulong, count, line_len);
+
+	memcpy(buf, line_str, copy_len);
+	buf[copy_len] = 0;
+	buf[strcspn(buf, "\n")] = 0;
+	*nr_read = copy_len;
+
+	return BSHELL_SUCCESS;
+}
+
+static enum bshell_status readline(
+	struct line_source *src,
+	fx_stringstream *out)
+{
+	struct file *f = (struct file *)src;
+	fx_wchar c = FX_WCHAR_INVALID;
+	size_t nr_read = 0;
+
+	while (1) {
+		fx_status status = fx_stream_read_char(f->f_strp, &c);
+		if (!FX_OK(status)) {
+			break;
+		}
+
+		fx_stream_write_char(out, c);
+		nr_read++;
+
+		if (c == '\n') {
+			break;
+		}
+	}
+
+	if (nr_read == 0) {
+		return BSHELL_ERR_EOF;
+	}
+
+	return BSHELL_SUCCESS;
+}
+
+enum bshell_status file_open(const char *path, struct file **out)
+{
+	FILE *fp = fopen(path, "r");
+	if (!fp) {
+		return bshell_status_from_errno(errno);
+	}
+
+	fx_stream *strp = fx_stream_open_fp(fp);
+
+	struct file *file = malloc(sizeof *file);
+	if (!file) {
+		fclose(fp);
+		return BSHELL_ERR_NO_MEMORY;
+	}
+
+	memset(file, 0x0, sizeof *file);
+
+	file->f_base.s_get_name = get_name;
+	file->f_base.s_get_row = get_row;
+	file->f_base.s_readline = readline;
+	file->f_fp = fp;
+	file->f_strp = strp;
+	file->f_path = fx_strdup(path);
+	file->f_lines = fx_array_create();
+
+	*out = file;
+
+	return BSHELL_SUCCESS;
+}
+
+void file_close(struct file *file)
+{
+	fx_stream_unref(file->f_strp);
+	fx_array_unref(file->f_lines);
+	free(file->f_path);
+	fclose(file->f_fp);
+	free(file);
+}