From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Sat, 06 Sep 2025 02:11:13 +0200 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1uugWQ-008dSh-0J for lore@lore.pengutronix.de; Sat, 06 Sep 2025 02:11:13 +0200 Received: from bombadil.infradead.org ([2607:7c80:54:3::133]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1uugWM-0008FE-6W for lore@pengutronix.de; Sat, 06 Sep 2025 02:11:13 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Cc:Content-ID:Content-Description:Resent-Date:Resent-From :Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=h56gNxnYLMUAHIR6OU50gt7uklQsxgXHxjuKostdkYU=; b=RpvUIPRL5/Yac1R1+kfZB24v6u zQUVL+ejGqmhW2+ViX7tKMDw56Nya+8KvSCpHzxl+di+xp+EdNqxXs4eKyn4v2EpeiLeYd3o7SPLm 9HXZfSdPbmVdrr3OABopsYDOmp/cLA3zdmaAFgoJWuX3kecRYmgML5bSbnQR2qEXlbd5/3ACJDf1G mV6ODpIT/o8CjPnJl/xfhXy3CkuAqugrJMN52f5Dl39FCI4tpbcVyCSifAjOAHqqju68mLtUok5GD en8mnXxMW6DVWAss4UyRtTIQrFmBAE2SxXS0omGSnrIqEhAh02up9xtao+V6r3W8YptL/EKmvzh2K 8ba42Bkg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uugVP-00000005R7z-0DyS; Sat, 06 Sep 2025 00:10:11 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uuZIy-000000037KQ-05Iv for barebox@lists.infradead.org; Fri, 05 Sep 2025 16:28:53 +0000 Received: from ptz.office.stw.pengutronix.de ([2a0a:edc0:0:900:1d::77] helo=[127.0.0.1]) by metis.whiteo.stw.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1uuZIw-0001RC-PN; Fri, 05 Sep 2025 18:28:50 +0200 Message-ID: Date: Fri, 5 Sep 2025 18:28:50 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird To: Tobias Waldekranz , barebox@lists.infradead.org References: <20250828150637.2222474-1-tobias@waldekranz.com> <20250828150637.2222474-2-tobias@waldekranz.com> <96be67c8-e10e-40f7-9945-76ccfa8d0aac@pengutronix.de> <87wm6e2vdp.fsf@waldekranz.com> Content-Language: en-US, de-DE, de-BE From: Ahmad Fatoum In-Reply-To: <87wm6e2vdp.fsf@waldekranz.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250905_092852_071454_6C931034 X-CRM114-Status: GOOD ( 32.43 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:3::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.whiteo.stw.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-5.3 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: Re: [PATCH 1/5] string: add strtok/strtokv X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.whiteo.stw.pengutronix.de) Hi, On 9/4/25 3:35 PM, Tobias Waldekranz wrote: > On tor, sep 04, 2025 at 13:00, Ahmad Fatoum wrote: >> Hello Tobias, >> >> On 8/28/25 5:05 PM, Tobias Waldekranz wrote: >>> Add an implementation of libc's standard strtok(3), which is useful >>> for tokenizing strings. >> >> strtok was previously removed in favor of strsep as it doesn't suffer >> from re-entrancy issues (poller and bthreads can run during delays). If >> you want to allow escapes, there's also strsep_unescaped. > > Aha, my bad. I did not realize that there was more than one thread of > execution. The pollers are run during delay loops for stuff like feeding a watchdog, blinking a heartbeat LED or polling network link state. Bthreads are currently only used for the USB mass storage gadget[1] and out-of-tree for baredoom, so it can be played while booting.. > strsep() is not quite the same thing though, I am really after the > strtok()'s behavior of skipping empty tokens. Ah, right. strsep is used in a loop, where it's just an extra check to skip empty tokens. > How would you feel about adding strtok_r() instead? You are not using anyways though, so what does it matter compared to while ((token = strsep(&sep, delims))) { if (!*token) continue; ? >>> Also, add a version that will collect all tokens from a string into an >>> array, which is useful in situations where you need to know how many >>> tokens there are, and when a token's relative position in the order is >>> significant. >> >> We have the inverse as strjoin, but not this. Maybe call it strsplit >> instead? > > If you accept my strtok_r() suggestion, do you still think strsplit() is > a better name, or is there value in signaling the underlying strtok() > behavior? I can see the argument that strjoin(strsplit(s)) should be s. Ok, let's keep it at strtokv. Some final bikeshedding: Would it be cleaner to return the string argument and have the length be the pointer argument? [1]: Implementing stackful coroutines was less of a hassle than rewriting a complex state machine implemented as a kthread.. Cheers, Ahmad > >> Cheers, >> Ahmad >> >>> >>> Signed-off-by: Tobias Waldekranz >>> --- >>> include/string.h | 2 ++ >>> lib/string.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++ >>> 2 files changed, 68 insertions(+) >>> >>> diff --git a/include/string.h b/include/string.h >>> index 71affe48b6..c8df8540d8 100644 >>> --- a/include/string.h >>> +++ b/include/string.h >>> @@ -8,6 +8,8 @@ >>> void *mempcpy(void *dest, const void *src, size_t count); >>> int strtobool(const char *str, int *val); >>> char *strsep_unescaped(char **, const char *, char *); >>> +char *strtok(char *str, const char *delim); >>> +int strtokv(char *str, const char *delim, char ***vecp); >>> char *stpcpy(char *dest, const char *src); >>> bool strends(const char *str, const char *postfix); >>> >>> diff --git a/lib/string.c b/lib/string.c >>> index 73637cd971..be7e65eb45 100644 >>> --- a/lib/string.c >>> +++ b/lib/string.c >>> @@ -593,6 +593,72 @@ char *strsep_unescaped(char **s, const char *ct, char *delim) >>> return sbegin; >>> } >>> >>> +/** >>> + * strtok - extract tokens from string >>> + * @str: string to split >>> + * @delim: set of delimiter characters >>> + * >>> + * The strtok() function breaks up a string into zero or more nonempty >>> + * tokens. On the first call, the string to be parsed should be >>> + * specified in @str. In each subsequent call that should parse the >>> + * same string, @str must be NULL. >>> + * >>> + * @delim specifies a set of bytes that delimit the tokens in the >>> + * string. >>> + * >>> + * Each call to strtok() returns a pointer to a string containing the >>> + * next token. This is done by replacing the first delimiter with a >>> + * NUL character, the operation is thus destructive to the string. If >>> + * no more tokens are found, strtok() returns NULL. >>> + */ >>> +char *strtok(char *str, const char *delim) >>> +{ >>> + static char *cursor; >>> + >>> + if (str) >>> + cursor = str; >>> + >>> + if (!cursor) >>> + return NULL; >>> + >>> + cursor += strspn(cursor, delim); >>> + if (*cursor == '\0') { >>> + cursor = NULL; >>> + return NULL; >>> + } >>> + >>> + return strsep(&cursor, delim); >>> +} >>> +EXPORT_SYMBOL(strtok); >>> + >>> +/** >>> + * strtokv - split string into array of tokens based on a delimiter set >>> + * @str: string to split >>> + * @delim: set of delimiter characters >>> + * @vecp: array of tokens >>> + * >>> + * Split @str into tokens delimited by @delim, using strtok(), and >>> + * store the allocated token array in @vecp, which the caller is >>> + * responsible for freeing. >>> + * >>> + * Return: The number of tokens in the array. >>> + */ >>> +int strtokv(char *str, const char *delim, char ***vecp) >>> +{ >>> + char *tok, **vec = NULL; >>> + int cnt = 0; >>> + >>> + >>> + for (tok = strtok(str, delim); tok; tok = strtok(NULL, delim)) { >>> + vec = xrealloc(vec, (cnt + 1) * sizeof(*vec)); >>> + vec[cnt++] = tok; >>> + } >>> + >>> + *vecp = vec; >>> + return cnt; >>> +} >>> +EXPORT_SYMBOL(strtokv); >>> + >>> #ifndef __HAVE_ARCH_STRSWAB >>> /** >>> * strswab - swap adjacent even and odd bytes in %NUL-terminated string >> >> -- >> Pengutronix e.K. | | >> Steuerwalder Str. 21 | http://www.pengutronix.de/ | >> 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | >> Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |