Re: the 1st hunk of Cyril Roelandt's patch to rats:
+ size_t len = snprintf(NULL, 0, "%s/%s", filename, dirdata->d_name) + 1;
Unfortunately, relying on the return value of snprintf isn't very portable, as
C99 and the Single Unix Specification v2 contradict each other on the
subject, cf. the glibc manual:
"*Attention:* In versions of the GNU C library prior to 2.1 the return
value is the number of characters stored, not including the
terminating null; unless there was not enough space in S to store the
result in which case `-1' is returned. This was changed in order to
comply with the ISO C99 standard."
(see also the NOTES in "man 3 snprintf" on linux).
A more portable, albeit less elegant solution is to calculate the
required size with strlen:
+ size_t len = strlen(filename) + 1 + strlen(dirdata->d_name) + 1;
Re: the 2nd hunk of the patch:
+ struct stat buf;
+ if(lstat(filename, &buf)==-1) {
+ return;
+ }
+ symname=calloc(buf.st_size, 1);
+ if(readlink(filename,symname,buf.st_size)==-1) {
'buf' and the call to lstat aren't necessary as there is a previous
call to lstat(filename, ...) in the same function. Also,
"calloc(buf.st_size,1)" seems to be an off-by-one error; you need
st_size+1; cf. POSIX:
"For symbolic links, [...] The value of the st_size member shall be
set to the length of the pathname contained in the symbolic link not
including any terminating null byte."
<http://pubs.opengroup.org/onlinepubs/9699919799/functions/lstat.html>
Amended patch attached.
diff --git a/engine.c b/engine.c
index e07e8ab..335cb67 100644
--- a/engine.c
+++ b/engine.c
@@ -1051,11 +1051,9 @@ void process_directory(char *filename, int forcelang) {
!strcmp(dirdata->d_name,"..")) {
continue;
}
- buf=calloc(PATH_MAX,1);
- sprintf(buf,
- "%s/%s",
- filename,
- dirdata->d_name);
+ size_t len = strlen(filename) + 1 + strlen(dirdata->d_name) + 1;
+ buf = calloc(len, 1);
+ snprintf(buf, len, "%s/%s", filename, dirdata->d_name);
process_file(buf,forcelang);
}
#endif
@@ -1093,9 +1091,8 @@ void process_file(char *filename, int forcelang)
/* Symbolic link check */
if(S_ISLNK(fstat.st_mode)) {
if(flags & FOLLOW_SYMLINK) {
- char *symname;
- symname=calloc(PATH_MAX,1);
- if(readlink(filename,symname,PATH_MAX)==-1) {
+ char *symname=calloc(fstat.st_size+1,1);
+ if(readlink(filename,symname,fstat.st_size+1)==-1) {
return;
}
process_file(symname,forcelang);
