From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from localhost (localhost [127.0.0.1]) by arlo.cworth.org (Postfix) with ESMTP id 23DCC6DE0943 for ; Fri, 8 Jul 2016 03:13:32 -0700 (PDT) X-Virus-Scanned: Debian amavisd-new at cworth.org X-Spam-Flag: NO X-Spam-Score: 0.135 X-Spam-Level: X-Spam-Status: No, score=0.135 tagged_above=-999 required=5 tests=[AWL=0.135] autolearn=disabled Received: from arlo.cworth.org ([127.0.0.1]) by localhost (arlo.cworth.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id c9fRaG2bnxFs for ; Fri, 8 Jul 2016 03:13:24 -0700 (PDT) Received: from che.mayfirst.org (che.mayfirst.org [162.247.75.118]) by arlo.cworth.org (Postfix) with ESMTP id 8F11E6DE02AC for ; Fri, 8 Jul 2016 03:13:09 -0700 (PDT) Received: from fifthhorseman.net (unknown [88.128.80.54]) by che.mayfirst.org (Postfix) with ESMTPSA id A5144F98B for ; Fri, 8 Jul 2016 06:13:08 -0400 (EDT) Received: by fifthhorseman.net (Postfix, from userid 1000) id 7F87D205C3; Fri, 8 Jul 2016 11:27:34 +0200 (CEST) From: Daniel Kahn Gillmor To: Notmuch Mail Subject: [PATCH v4 01/16] add util/search-path.{c, h} to test for executables in $PATH Date: Fri, 8 Jul 2016 11:27:12 +0200 Message-Id: <1467970047-8013-2-git-send-email-dkg@fifthhorseman.net> X-Mailer: git-send-email 2.8.1 In-Reply-To: <1467970047-8013-1-git-send-email-dkg@fifthhorseman.net> References: <1467970047-8013-1-git-send-email-dkg@fifthhorseman.net> X-BeenThere: notmuch@notmuchmail.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: "Use and development of the notmuch mail system." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 08 Jul 2016 10:13:32 -0000 This is a utility function we can use to see whether an executable is available. --- util/Makefile.local | 2 +- util/search-path.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ util/search-path.h | 24 ++++++++++++++++++++++++ 3 files changed, 75 insertions(+), 1 deletion(-) create mode 100644 util/search-path.c create mode 100644 util/search-path.h diff --git a/util/Makefile.local b/util/Makefile.local index 905f237..8b2b91b 100644 --- a/util/Makefile.local +++ b/util/Makefile.local @@ -5,7 +5,7 @@ extra_cflags += -I$(srcdir)/$(dir) libutil_c_srcs := $(dir)/xutil.c $(dir)/error_util.c $(dir)/hex-escape.c \ $(dir)/string-util.c $(dir)/talloc-extra.c $(dir)/zlib-extra.c \ - $(dir)/util.c + $(dir)/util.c $(dir)/search-path.c libutil_modules := $(libutil_c_srcs:.c=.o) diff --git a/util/search-path.c b/util/search-path.c new file mode 100644 index 0000000..9da21cb --- /dev/null +++ b/util/search-path.c @@ -0,0 +1,50 @@ +#include "search-path.h" +#include +#include +#include +#include +#include +#include + + +notmuch_bool_t +test_for_executable (const char *exename) +{ + char *path = NULL, *save = NULL, *tok; + notmuch_bool_t ret = FALSE; + + if (strchr (exename, '/')) { + if (0 == access (exename, X_OK)) + return TRUE; + else + return FALSE; + } + + path = getenv ("PATH"); + if (path) + path = strdup (path); + else { + size_t n = confstr (_CS_PATH, NULL, 0); + path = (char *) malloc (n); + if (! path) + return FALSE; + confstr (_CS_PATH, path, n); + } + + tok = strtok_r (path, ":", &save); + while (tok) { + int dir_fd = open (tok, O_DIRECTORY | O_RDONLY); + if (dir_fd != -1) { + int access = faccessat (dir_fd, exename, X_OK, 0); + close (dir_fd); + if (access == 0) { + ret = TRUE; + break; + } + } + tok = strtok_r (NULL, ":", &save); + } + if (path) + free (path); + return ret; +} diff --git a/util/search-path.h b/util/search-path.h new file mode 100644 index 0000000..14c4d14 --- /dev/null +++ b/util/search-path.h @@ -0,0 +1,24 @@ +#ifndef _SEARCH_PATH_H +#define _SEARCH_PATH_H + +#include "notmuch.h" + +/* can an executable be found with the given name? + * + * Return TRUE only if we can find something to execute with the + * associated name. + * + * if the name has a '/' in it, we look for it directly with + * access(exename, X_OK). + * + * otherwise, we look for it in $PATH (or in confstr(_CS_PATH), if + * $PATH is unset). + * + * This should match the logic for execvp (as well as matching user + * expectations, hopefully). + */ + +notmuch_bool_t +test_for_executable (const char *exename); + +#endif -- 2.8.1