[readline] Allow readline_history() to return a meaningful status

Signed-off-by: Michael Brown <mcb30@ipxe.org>

1 files changed, 19 insertions, 11 deletions

diff --git a/src/hci/readline.c b/src/hci/readline.c
index a199fb0e..d67980b2 100644
--- a/src/hci/readline.c
+++ b/src/hci/readline.c
@@ -22,6 +22,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
+#include <errno.h>
 #include <ipxe/console.h>
 #include <ipxe/keys.h>
 #include <ipxe/editstring.h>
@@ -244,18 +245,22 @@ void history_free ( struct readline_history *history ) {
  * @v prefill		Prefill string, or NULL for no prefill
  * @v history		History buffer, or NULL for no history
  * @ret line		Line read from console (excluding terminating newline)
+ * @ret rc		Return status code
  *
  * The returned line is allocated with malloc(); the caller must
  * eventually call free() to release the storage.
  */
-char * readline_history ( const char *prompt, const char *prefill,
-			  struct readline_history *history ) {
+int readline_history ( const char *prompt, const char *prefill,
+		       struct readline_history *history, char **line ) {
 	char buf[READLINE_MAX];
 	struct edit_string string;
 	int key;
 	int move_by;
 	const char *new_string;
-	char *line;
+	int rc;
+
+	/* Avoid returning uninitialised data on error */
+	*line = NULL;
 
 	/* Display prompt, if applicable */
 	if ( prompt )
@@ -280,12 +285,11 @@ char * readline_history ( const char *prompt, const char *prefill,
 		switch ( key ) {
 		case CR:
 		case LF:
-			line = strdup ( buf );
-			if ( ! line )
-				printf ( "\nOut of memory" );
+			*line = strdup ( buf );
+			rc = ( ( *line ) ? 0 : -ENOMEM );
 			goto done;
 		case CTRL_C:
-			line = NULL;
+			rc = -ECANCELED;
 			goto done;
 		case KEY_UP:
 			move_by = 1;
@@ -311,11 +315,12 @@ char * readline_history ( const char *prompt, const char *prefill,
  done:
 	putchar ( '\n' );
 	if ( history ) {
-		if ( line && line[0] )
-			history_append ( history, line );
+		if ( *line && (*line)[0] )
+			history_append ( history, *line );
 		history_cleanup ( history );
 	}
-	return line;
+	assert ( ( rc == 0 ) ^ ( *line == NULL ) );
+	return rc;
 }
 
 /**
@@ -328,5 +333,8 @@ char * readline_history ( const char *prompt, const char *prefill,
  * eventually call free() to release the storage.
  */
 char * readline ( const char *prompt ) {
-	return readline_history ( prompt, NULL, NULL );
+	char *line;
+
+	readline_history ( prompt, NULL, NULL, &line );
+	return line;
 }