hush: fix read builtin to not read ahead past eol and to not use

[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 44cf448691a37c05b0b238af59bc4a441d41b13b..1eb4af13c975990d73217ecae6f56bc20e0f6bf5 100644 (file)
--- a/libbb/get_line_from_file.c
+++ b/libbb/get_line_from_file.c
@@ -9,14 +9,13 @@
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */
 
-#include <stdio.h>
-#include <stdlib.h>
 #include "libbb.h"
 
-/* get_line_from_file() - This function reads an entire line from a text file,
- * up to a newline or NUL byte.  It returns a malloc'ed char * which must be
- * stored and free'ed  by the caller.  If end is null '\n' isn't considered
- * and of line.  If end isn't null, length of the chunk read is stored in it. */
+/* 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
+ * stored and 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 *bb_get_chunk_from_file(FILE *file, int *end)
 {
@@ -27,36 +26,45 @@ char *bb_get_chunk_from_file(FILE *file, int *end)
 
        while ((ch = getc(file)) != EOF) {
                /* grow the line buffer as necessary */
-               if (idx > linebufsz - 2) {
-                       linebuf = xrealloc(linebuf, linebufsz += 80);
+               if (idx >= linebufsz) {
+                       linebufsz += 80;
+                       linebuf = xrealloc(linebuf, linebufsz);
                }
-               linebuf[idx++] = (char)ch;
-               if (!ch || (end && ch == '\n')) break;
+               linebuf[idx++] = (char) ch;
+               if (!ch || (end && ch == '\n'))
+                       break;
        }
-       if (end) *end = idx;
+       if (end)
+               *end = idx;
        if (linebuf) {
-               if (ferror(file)) {
-                       free(linebuf);
-                       return NULL;
-               }
-               linebuf[idx] = 0;
+               // huh, does fgets discard prior data on error like this?
+               // I don't think so....
+               //if (ferror(file)) {
+               //      free(linebuf);
+               //      return NULL;
+               //}
+               linebuf = xrealloc(linebuf, idx+1);
+               linebuf[idx] = '\0';
        }
        return linebuf;
 }
 
-/* Get line, including trailing /n if any */
-char *bb_get_line_from_file(FILE *file)
+/* Get line, including trailing \n if any */
+char *xmalloc_fgets(FILE *file)
 {
        int i;
+
        return bb_get_chunk_from_file(file, &i);
 }
 
-/* Get line.  Remove trailing /n */
-char *bb_get_chomped_line_from_file(FILE *file)
+/* Get line.  Remove trailing \n */
+char *xmalloc_getline(FILE *file)
 {
        int i;
-       char *c=bb_get_chunk_from_file(file, &i);
-       if(i) c[--i]=0;
-       
+       char *c = bb_get_chunk_from_file(file, &i);
+
+       if (i && c[--i] == '\n')
+               c[i] = '\0';
+
        return c;
 }