busybox/libbb/xreadlink.c
Denis Vlasenko b68979aefa insmod: code shrink, stop exporting insmod_ng_main.
function                                             old     new   delta
add_ksymoops_symbols                                   -     421    +421
static.section_names                                  20      40     +20
lsmod_main                                           425     424      -1
set_tainted                                          153     150      -3
main_opts                                              4       -      -4
obj_symbol_patch                                      47      42      -5
obj_string_patch                                     144     139      -5
already_loaded                                       144     138      -6
check_dep                                            348     341      -7
append_option                                         75      68      -7
obj_allocate_commons                                 515     501     -14
new_process_module_arguments                        1039    1018     -21
arch_new_symbol                                       31       9     -22
check_module_name_match                               85      61     -24
obj_create_alloced_section                           164     136     -28
include_conf                                         930     902     -28
modprobe_main                                       1643    1535    -108
obj_load                                             924     777    -147
insmod_ng_main                                       245       -    -245
insmod_main                                         4122    3794    -328
------------------------------------------------------------------------------
(add/remove: 1/2 grow/shrink: 1/16 up/down: 441/-1003)       Total: -562 bytes
   text    data     bss     dec     hex filename
 776020     974    9420  786414   bffee busybox_old
 775384     974    9420  785778   bfd72 busybox_unstripped
2007-11-02 23:31:10 +00:00

60 lines
1.2 KiB
C

/* vi: set sw=4 ts=4: */
/*
* xreadlink.c - safe implementation of readlink.
* Returns a NULL on failure...
*/
#include "libbb.h"
/*
* NOTE: This function returns a malloced char* that you will have to free
* yourself. You have been warned.
*/
char *xmalloc_readlink(const char *path)
{
enum { GROWBY = 80 }; /* how large we will grow strings by */
char *buf = NULL;
int bufsize = 0, readsize = 0;
do {
bufsize += GROWBY;
buf = xrealloc(buf, bufsize);
readsize = readlink(path, buf, bufsize);
if (readsize == -1) {
free(buf);
return NULL;
}
} while (bufsize < readsize + 1);
buf[readsize] = '\0';
return buf;
}
char *xmalloc_readlink_or_warn(const char *path)
{
char *buf = xmalloc_readlink(path);
if (!buf) {
/* EINVAL => "file: Invalid argument" => puzzled user */
bb_error_msg("%s: cannot read link (not a symlink?)", path);
}
return buf;
}
/* UNUSED */
#if 0
char *xmalloc_realpath(const char *path)
{
#if defined(__GLIBC__) && !defined(__UCLIBC__)
/* glibc provides a non-standard extension */
return realpath(path, NULL);
#else
char buf[PATH_MAX+1];
/* on error returns NULL (xstrdup(NULL) ==NULL) */
return xstrdup(realpath(path, buf));
#endif
}
#endif