From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-20.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 745E5C2BBCA for ; Thu, 17 Dec 2020 09:47:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3F961238E1 for ; Thu, 17 Dec 2020 09:47:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727066AbgLQJrR (ORCPT ); Thu, 17 Dec 2020 04:47:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49144 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726890AbgLQJrR (ORCPT ); Thu, 17 Dec 2020 04:47:17 -0500 Received: from mail-wr1-x436.google.com (mail-wr1-x436.google.com [IPv6:2a00:1450:4864:20::436]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 576F0C0611CB for ; Thu, 17 Dec 2020 01:46:36 -0800 (PST) Received: by mail-wr1-x436.google.com with SMTP id q18so18390258wrn.1 for ; Thu, 17 Dec 2020 01:46:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=r+YUtLl/Hf8N/iAQo2QQM3eGnDGMajLkjE2wfra0Wbo=; b=YaGAJtKmNigO5Aof9I+o0gpD+GeJ5ObdWiaV80qU2gOh6YR/LBJWmDL3LP9C0P6vO3 b8eXBtngHMu6SAObXhFq1CPUh87G6CfLWy4c4gBZp0ZQmY06oTj9KusoU5esBpK87WN+ imtjgOJNXjWRHBe2NopWp3R6tcVptlLxvP4smCzPBY/o2LdYfRkYYl4JFtqZGuo61q6W pa6v7AaOs3X0FBxOGD6XaxvK7Afmv1ONCxVEXd/YhdX8PcknoISv+N9P+hd0cJqw+E5A Rg1HE+XkYyF1QCnxKYCbhb4F1ssHFR3K11OfQoAv5bWA/XBY/NAiDm0CvHAEgap96taC ixSQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=r+YUtLl/Hf8N/iAQo2QQM3eGnDGMajLkjE2wfra0Wbo=; b=N6AH213AIcjyZvvUheep0LdaS4RJVkOQwsJLIw7eTXJdS+Om0Zzu8hdnbBch1W63PZ 3V/Qj3evxfl63MJTORhNhTbpTwEYPtk2levyeCiqLk6Oa825foLA6Zt8Q87PEfO7Zu4L q7Sqkvjbk13I1O1AN+9t+fXYXg2NaEUi02ty/c+qOlM4dBIdieJXHDFFZ3yFaKX4pAP2 EIcmXWAc0alrzLhIFtvn2pNhamEJ/vd3rjovDiOrt9pom1t5BpFHWzncwxOvW6al0nsN xgcGQHnxKFRCWYVw/mRxjVThK+DvgveNxKF/EfbvgB++Um/z3eOaE9qH37rdXUGJaPz8 6EUg== X-Gm-Message-State: AOAM532dKEYZOMRlwcesgYwLBV8Rmh+uCzVaO5ULnj3ZBJTHQajAGrrS dwcu2j1txCjckwGKCKOy/M0= X-Google-Smtp-Source: ABdhPJyiOHlalWQEKoaL8HmMRsf7bP3mzr0mCnJqaGVDbFPQBYFY9kovLl9T93+XGy/fyjsLKtsPfQ== X-Received: by 2002:adf:9cc6:: with SMTP id h6mr42512065wre.341.1608198395097; Thu, 17 Dec 2020 01:46:35 -0800 (PST) Received: from oberon.zico.biz ([83.222.187.186]) by smtp.gmail.com with ESMTPSA id o125sm6773164wmo.30.2020.12.17.01.46.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Dec 2020 01:46:34 -0800 (PST) From: "Tzvetomir Stoyanov (VMware)" To: rostedt@goodmis.org Cc: linux-trace-devel@vger.kernel.org Subject: [PATCH 6/9] libtracefs man pages: APIs for working with files in trace instances. Date: Thu, 17 Dec 2020 11:46:23 +0200 Message-Id: <20201217094626.1402191-7-tz.stoyanov@gmail.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201217094626.1402191-1-tz.stoyanov@gmail.com> References: <20201217094626.1402191-1-tz.stoyanov@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org Documented APIs: tracefs_file_exists() tracefs_dir_exists() tracefs_instance_get_file() tracefs_instance_get_dir() tracefs_instance_file_write() tracefs_instance_file_read() Signed-off-by: Tzvetomir Stoyanov (VMware) --- Documentation/libtracefs-instances-files.txt | 157 +++++++++++++++++++ 1 file changed, 157 insertions(+) create mode 100644 Documentation/libtracefs-instances-files.txt diff --git a/Documentation/libtracefs-instances-files.txt b/Documentation/libtracefs-instances-files.txt new file mode 100644 index 0000000..f1e9707 --- /dev/null +++ b/Documentation/libtracefs-instances-files.txt @@ -0,0 +1,157 @@ +libtracefs(3) +============= + +NAME +---- +tracefs_file_exists, tracefs_dir_exists, tracefs_instance_get_file, +tracefs_instance_get_dir, tracefs_instance_file_write, +tracefs_instance_file_read - Work with files in tracing instances. + +SYNOPSIS +-------- +[verse] +-- +*#include * + +bool *tracefs_file_exists*(struct tracefs_instance pass:[*]_instance_, char pass:[*]_name_); +bool *tracefs_dir_exists*(struct tracefs_instance pass:[*]_instance_, char pass:[*]_name_); +char pass:[*]*tracefs_instance_get_file*(struct tracefs_instance pass:[*]_instance_, const char pass:[*]_file_); +char pass:[*]*tracefs_instance_get_dir*(struct tracefs_instance pass:[*]_instance_); +int *tracefs_instance_file_write*(struct tracefs_instance pass:[*]_instance_, const char pass:[*]_file_, const char pass:[*]_str_); +char pass:[*]*tracefs_instance_file_read*(struct tracefs_instance pass:[*]_instance_, char pass:[*]_file_, int pass:[*]_psize_); + +-- + +DESCRIPTION +----------- +This set of APIs can be used to work with trace files in all trace instances. +All they have _instance_ argument, to limit the scope on the given trace _instance_ only. +If _instance_ is NULL, the scope is limited to the main trace instance. + +The _tracefs_file_exists()_ function checks if a file with _name_ exists in _instance_. + +The _tracefs_dir_exists()_ function checks if a directory with _name_ exists in _instance_. + +The _tracefs_instance_get_file()_ function returns the full path of the file with +given _name_ in _instance_. + +The _tracefs_instance_get_dir()_ function returns the full path of the directory with +given _name_ in _instance_. + +The _tracefs_instance_file_write()_ function writes a string _str_ in a _file_ from +the given _instance_, without the terminating NULL character. + +The _tracefs_instance_file_read()_ function reads the content of a _file_ from +the given _instance_. + +RETURN VALUE +------------ +The _tracefs_file_exists()_ and _tracefs_dir_exists()_ functions return true if the +file / directory exist in the given instance or false if they do not exist. + +The _tracefs_instance_get_file()_ and _tracefs_instance_get_dir()_ functions return +a string or NULL in case of an error. The returned string must be freed with +_tracefs_put_tracing_file()_. + +The _tracefs_instance_file_write()_ function returns the number of written bytes, +or -1 in case of an error. + +The _tracefs_instance_file_read()_ function returns a pointer to a NULL terminated +string, read from the file, or NULL in case of an error. The returned string must +be freed with free(). + +EXAMPLE +------- +[source,c] +-- +#include + +struct tracefs_instance *inst = tracefs_instance_create("foo"); + if (!inst) { + /* Error creating a new trace instance */ + ... + } + + if (tracefs_file_exists(inst,"trace_clock")) { + /* The instance foo supports trace clock */ + char *path, *clock; + int size; + + path = = tracefs_instance_get_file(inst, "trace_clock") + if (!path) { + /* Error getting the path to trace_clock file in instance foo */ + ... + } + ... + tracefs_put_tracing_file(path); + + clock = tracefs_instance_file_read(inst, "trace_clock", &size); + if (!clock) { + /* Failed to read trace_clock file in instance foo */ + ... + } + ... + free(clock); + + if (tracefs_instance_file_write(inst, "trace_clock", "global") != strlen("global")) { + /* Failed to set gloabl trace clock in instance foo */ + ... + } + } else { + /* The instance foo does not support trace clock */ + } + + if (tracefs_dir_exists(inst,"options")) { + /* The instance foo supports trace options */ + char *path = tracefs_instance_get_file(inst, "options"); + if (!path) { + /* Error getting the path to options directory in instance foo */ + ... + } + + tracefs_put_tracing_file(path); + } else { + /* The instance foo does not support trace options */ + } + + ... + + if (tracefs_instance_is_new(inst)) + tracefs_instance_destroy(inst); + else + tracefs_instance_free(inst); +-- +FILES +----- +[verse] +-- +*tracefs.h* + Header file to include in order to have access to the library APIs. +*-ltracefs* + Linker switch to add when building a program that uses the library. +-- + +SEE ALSO +-------- +_libtracefs(3)_, +_libtraceevent(3)_, +_trace-cmd(1)_ + +AUTHOR +------ +[verse] +-- +*Steven Rostedt* +*Tzvetomir Stoyanov* +-- +REPORTING BUGS +-------------- +Report bugs to + +LICENSE +------- +libtracefs is Free Software licensed under the GNU LGPL 2.1 + +RESOURCES +--------- +https://git.kernel.org/pub/scm/libs/libtrace/libtracefs.git/ \ No newline at end of file -- 2.28.0