diff options
Diffstat (limited to 'gl/lib/areadlink-with-size.c')
| -rw-r--r-- | gl/lib/areadlink-with-size.c | 36 |
1 files changed, 30 insertions, 6 deletions
diff --git a/gl/lib/areadlink-with-size.c b/gl/lib/areadlink-with-size.c index eacad3f6..95a28b31 100644 --- a/gl/lib/areadlink-with-size.c +++ b/gl/lib/areadlink-with-size.c @@ -26,6 +26,7 @@ #include <limits.h> #include <stdint.h> #include <stdlib.h> +#include <string.h> #include <unistd.h> #ifndef SSIZE_MAX @@ -60,18 +61,28 @@ areadlink_with_size (char const *file, size_t size) ? symlink_max + 1 : INITIAL_LIMIT_BOUND); + enum { stackbuf_size = 128 }; + /* The initial buffer size for the link value. */ - size_t buf_size = size < initial_limit ? size + 1 : initial_limit; + size_t buf_size = (size == 0 ? stackbuf_size + : size < initial_limit ? size + 1 : initial_limit); while (1) { ssize_t r; size_t link_length; - char *buffer = malloc (buf_size); + char stackbuf[stackbuf_size]; + char *buf = stackbuf; + char *buffer = NULL; + + if (! (size == 0 && buf_size == stackbuf_size)) + { + buf = buffer = malloc (buf_size); + if (!buffer) + return NULL; + } - if (buffer == NULL) - return NULL; - r = readlink (file, buffer, buf_size); + r = readlink (file, buf, buf_size); link_length = r; /* On AIX 5L v5.3 and HP-UX 11i v2 04/09, readlink returns -1 @@ -86,7 +97,20 @@ areadlink_with_size (char const *file, size_t size) if (link_length < buf_size) { - buffer[link_length] = 0; + buf[link_length] = 0; + if (!buffer) + { + buffer = malloc (link_length + 1); + if (buffer) + return memcpy (buffer, buf, link_length + 1); + } + else if (link_length + 1 < buf_size) + { + /* Shrink BUFFER before returning it. */ + char *shrinked_buffer = realloc (buffer, link_length + 1); + if (shrinked_buffer != NULL) + buffer = shrinked_buffer; + } return buffer; } |