lineedit: do not hang on error, but return error indicator.

[oweals/busybox.git] / libbb / get_line_from_file.c

diff --git a/libbb/get_line_from_file.c b/libbb/get_line_from_file.c
index 968d7572df50cb2b6d0571ad125de8ba08ccd3e4..a0ed9193fa3eed30d34a8996217137a1d7f9d921 100644 (file)
--- a/libbb/get_line_from_file.c
+++ b/libbb/get_line_from_file.c
@@ -6,21 +6,20 @@
  * Copyright (C) 2004 Erik Andersen <andersen@codepoet.org>
  * Copyright (C) 2001 Matt Krai
  *
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
 
-/* for getline() [GNUism] */
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE 1
-#endif
 #include "libbb.h"
 
 /* This function reads an entire line from a text file, up to a newline
  * or NUL byte, inclusive.  It returns a malloc'ed char * which
  * must be free'ed by the caller.  If end is NULL '\n' isn't considered
- * end of line.  If end isn't NULL, length of the chunk read is stored in it.
- * Return NULL if EOF/error */
-char* FAST_FUNC bb_get_chunk_from_file(FILE *file, int *end)
+ * end of line.  If end isn't NULL, length of the chunk is stored in it.
+ * If lineno is not NULL, *lineno is incremented for each line,
+ * and also trailing '\' is recognized as line continuation.
+ *
+ * Returns NULL if EOF/error. */
+char* FAST_FUNC bb_get_chunk_with_continuation(FILE *file, int *end, int *lineno)
 {
        int ch;
        int idx = 0;
@@ -30,12 +29,20 @@ char* FAST_FUNC bb_get_chunk_from_file(FILE *file, int *end)
        while ((ch = getc(file)) != EOF) {
                /* grow the line buffer as necessary */
                if (idx >= linebufsz) {
-                       linebufsz += 80;
+                       linebufsz += 256;
                        linebuf = xrealloc(linebuf, linebufsz);
                }
                linebuf[idx++] = (char) ch;
-               if (!ch || (end && ch == '\n'))
+               if (!ch)
                        break;
+               if (end && ch == '\n') {
+                       if (lineno == NULL)
+                               break;
+                       (*lineno)++;
+                       if (idx < 2 || linebuf[idx-2] != '\\')
+                               break;
+                       idx -= 2;
+               }
        }
        if (end)
                *end = idx;
@@ -52,6 +59,11 @@ char* FAST_FUNC bb_get_chunk_from_file(FILE *file, int *end)
        return linebuf;
 }
 
+char* FAST_FUNC bb_get_chunk_from_file(FILE *file, int *end)
+{
+       return bb_get_chunk_with_continuation(file, end, NULL);
+}
+
 /* Get line, including trailing \n if any */
 char* FAST_FUNC xmalloc_fgets(FILE *file)
 {
@@ -72,7 +84,6 @@ char* FAST_FUNC xmalloc_fgetline(FILE *file)
 }
 
 #if 0
-
 /* GNUism getline() should be faster (not tested) than a loop with fgetc */
 
 /* Get line, including trailing \n if any */