Raymond Toy pushed to branch issue-130-file-author-in-c at cmucl / cmucl

Commits: 518ef959 by Carl S. Shapiro at 2022-09-05T04:59:53+00:00 Apply 1 suggestion(s) to 1 file(s) - - - - -

1 changed file:

- src/lisp/os-common.c

Changes:

===================================== src/lisp/os-common.c ===================================== @@ -727,66 +727,42 @@ os_lstat(const char* path, u_int64_t *dev, u_int64_t *ino, unsigned int *mode, u char * os_file_author(const char *path) { - int status; - struct stat statbuf; - char* author = NULL; - bool nomem = false; - size_t bufsize; - char* buf = NULL; - char* buf2 = NULL; + struct stat sb; + char initial[1024]; + char *buffer, *obuffer; + size_t size; struct passwd pwd; - struct passwd *result = NULL; - - status = stat(path, &statbuf); + struct passwd *ppwd; + char *result;

- if (status != 0) { + if (stat(path, &sb) != 0) { return NULL; } - - bufsize = sysconf(_SC_GETPW_R_SIZE_MAX); - - /* - * If sysconf fails, just use a small initial buffer size that we - * will keep growing up to some maximum size. - */ - if (bufsize == -1) { - bufsize = 1024; - } - - while (1) { - buf2 = realloc(buf, bufsize); - - if (buf2 == NULL) { - result = NULL; - nomem = true; - break; - } - - buf = buf2; - status = getpwuid_r(statbuf.st_uid, &pwd, buf, bufsize, &result); - - if (status != 0) { - result = NULL; - } - if ((result != NULL) || (status != ERANGE)) { - break; - } - /* If bufsize exceeds some large size, give up. */ - if (bufsize > 16384) { - nomem = true; - break; + result = NULL; + buffer = initial; + size = ARRAYSIZE(initial); + assert(sysconf(_SC_GETPW_R_SIZE_MAX) <= 16384)); + while (size <= 16384) { + switch (getpwuid_r(sb.st_uid, &pwd, buffer, size, &ppwd)) { + case 0: + /* Success, though we might not have a matching entry */ + result = (ppwd == NULL) ? NULL : strdup(pwd.pw_name); + goto exit; + case ERANGE: + /* Buffer is too small, double its size and try again */ + size *= 2; + obuffer = (buffer == initial) ? NULL : buffer; + if ((buffer = realloc(obuffer, size)) == NULL) { + free(obuffer); + goto exit; + } + continue; + default: + /* All other errors */ + goto exit; } - - bufsize <<= 1; } - - if (result) { - author = strdup(result->pw_name); - } - - if (buf) { - free(buf); - } - - return author; +exit: + free(buffer); + return result; }

View it on GitLab: https://gitlab.common-lisp.net/cmucl/cmucl/-/commit/518ef95922f48ff2e2908786...