diff options
| -rw-r--r-- | src/libutil/util.cc | 23 |
1 files changed, 11 insertions, 12 deletions
diff --git a/src/libutil/util.cc b/src/libutil/util.cc index 9346d5dc4cf8..16c2c97aac9b 100644 --- a/src/libutil/util.cc +++ b/src/libutil/util.cc @@ -216,18 +216,17 @@ bool pathExists(const Path & path) Path readLink(const Path & path) { checkInterrupt(); - struct stat st = lstat(path); - if (!S_ISLNK(st.st_mode)) - throw Error(format("'%1%' is not a symlink") % path); - auto bufSize = std::max(st.st_size, (off_t) PATH_MAX + 1); - char buf[bufSize]; - ssize_t rlsize = readlink(path.c_str(), buf, bufSize); - if (rlsize == -1) - throw SysError(format("reading symbolic link '%1%'") % path); - else if (rlsize > bufSize) - throw Error(format("symbolic link '%1%' size overflow %2% > %3%") - % path % rlsize % bufSize); - return string(buf, rlsize); + for (ssize_t bufSize = PATH_MAX/4; true; bufSize += bufSize/2) { + char buf[bufSize]; + ssize_t rlSize = readlink(path.c_str(), buf, bufSize); + if (rlSize == -1) + if (errno == EINVAL) + throw Error(format("'%1%' is not a symlink") % path); + else + throw SysError(format("reading symbolic link '%1%'") % path); + else if (rlSize < bufSize) + return string(buf, rlSize); + } } |