From patchwork Mon Nov 19 12:54:21 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tzvetomir Stoyanov X-Patchwork-Id: 10759761 Return-Path: Received: from mail-eopbgr810089.outbound.protection.outlook.com ([40.107.81.89]:53856 "EHLO NAM01-BY2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728890AbeKSXR4 (ORCPT ); Mon, 19 Nov 2018 18:17:56 -0500 From: Tzvetomir Stoyanov To: "rostedt@goodmis.org" CC: "linux-trace-devel@vger.kernel.org" Subject: [PATCH 11/34] tools/lib/traceevent: Man pages tep_get_any_field_val(), tep_get_common_field_val(), tep_get_field_val() and tep_get_field_raw() Date: Mon, 19 Nov 2018 12:54:21 +0000 Message-ID: <20181119125357.19449-12-tstoyanov@vmware.com> References: <20181119125357.19449-1-tstoyanov@vmware.com> In-Reply-To: <20181119125357.19449-1-tstoyanov@vmware.com> Content-Language: en-US MIME-Version: 1.0 Sender: linux-trace-devel-owner@vger.kernel.org List-ID: Content-Length: 4916 Create man pages for tep_get_any_field_val(), tep_get_common_field_val(), tep_get_field_val() and tep_get_field_raw() as part of the libtraceevent APIs. Signed-off-by: Tzvetomir Stoyanov --- .../libtraceevent-field_get_val.txt | 117 ++++++++++++++++++ 1 file changed, 117 insertions(+) create mode 100644 tools/lib/traceevent/Documentation/libtraceevent-field_get_val.txt diff --git a/tools/lib/traceevent/Documentation/libtraceevent-field_get_val.txt b/tools/lib/traceevent/Documentation/libtraceevent-field_get_val.txt new file mode 100644 index 000000000000..4d2b99bf342f --- /dev/null +++ b/tools/lib/traceevent/Documentation/libtraceevent-field_get_val.txt @@ -0,0 +1,117 @@ +libtraceevent(3) +================ + +NAME +---- +tep_get_any_field_val,tep_get_common_field_val,tep_get_field_val,tep_get_field_raw - Get value of a field. + +SYNOPSIS +-------- +[verse] +-- +*#include * +*#include * + +int *tep_get_any_field_val*(struct trace_seq pass:[*]_s_, struct tep_event pass:[*]_event_, const char pass:[*]_name_, struct tep_record pass:[*]_record_, unsigned long long pass:[*]_val_, int _err_); +int *tep_get_common_field_val*(struct trace_seq pass:[*]_s_, struct tep_event pass:[*]_event_, const char pass:[*]_name_, struct tep_record pass:[*]_record_, unsigned long long pass:[*]_val_, int _err_); +int *tep_get_field_val*(struct trace_seq pass:[*]_s_, struct tep_event pass:[*]_event_, const char pass:[*]_name_, struct tep_record pass:[*]_record_, unsigned long long pass:[*]_val_, int _err_); +void pass:[*]*tep_get_field_raw*(struct trace_seq pass:[*]_s_, struct tep_event pass:[*]_event_, const char pass:[*]_name_, struct tep_record pass:[*]_record_, int pass:[*]_len_, int _err_); +-- + +DESCRIPTION +----------- +These functions can be used to find a field and retrieve its value. + +The _tep_get_any_field_val()_ function searches in the _record_ for a filed with +_name_, part of the _event_. If the field is found, its value is stored in _val_. +In case of an error, an error string is printed into _s_, if _err_ is not 0. + +The _tep_get_common_field_val()_ function does the same as +_tep_get_any_field_val()_, but searches only in the common fields. + +The _tep_get_field_val()_ function does the same as +_tep_get_any_field_val()_, but searches only in the event specific fields. + +The _tep_get_field_raw()_ function searches in the _record_ for a filed with _name_, +part of the _event_. If the field is found, a pointer to its raw data is returned. +The size of the data is stored in _len_. In case of an error, an error string +is printed into _s_, if _err_ is not 0. + +RETURN VALUE +------------ +The _tep_get_any_field_val()_, _tep_get_common_field_val()_ and +_tep_get_field_val()_ functions return 0 on success, or -1 in case of an error. + +The _tep_get_field_raw()_ function returns a pointer to field's raw data, and +places the length of this data in _len_. In case of an error NULL is returned. + +EXAMPLE +------- +[source,c] +-- +#include +#include +... +struct tep_handle *tep = tep_alloc(); +... +struct tep_event *event = tep_find_event_by_name(tep, "kvm", "kvm_exit"); +... +void process_record(struct tep_record *record) +{ + int len; + char *comm; + struct tep_event_format *event; + unsigned long long val; + + event = tep_find_event_by_record(pevent, record); + if (event != NULL) { + if (tep_get_common_field_val(NULL, event, "common_type", record, &val, 0) == 0) { + /* Got the value of common type field */ + } + if (tep_get_field_val(NULL, event, "pid", record, &val, 0) == 0) { + /* Got the value of pid specific field */ + } + comm = tep_get_field_raw(NULL, event, "comm", record, &len, 0); + if (comm != NULL) { + /* Got a pointer to the comm event specific field */ + } + } +} +-- + +FILES +----- +[verse] +-- +*event-parse.h* + Header file to include in order to have access to the library APIs. +*trace-seq.h* + Header file to include in order to have access to trace sequences related APIs. + Trace sequences are used to allow a function to call several other functions + to create a string of data to use. +*-ltraceevent* + Linker switch to add when building a program that uses the library. +-- + +SEE ALSO +-------- +_libtraceevent(3)_, _trace-cmd(1)_ + +AUTHOR +------ +[verse] +-- +*Steven Rostedt* , author of *libtraceevent*. +*Tzvetomir Stoyanov* , author of this man page. +-- +REPORTING BUGS +-------------- +Report bugs to + +LICENSE +------- +libtraceevent is Free Software licensed under the GNU LGPL 2.1 + +RESOURCES +--------- +https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git