mirror of https://gitee.com/openkylin/linux.git
82 lines
1.8 KiB
Plaintext
82 lines
1.8 KiB
Plaintext
libtraceevent(3)
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================
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NAME
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----
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tep_read_number_field - Reads a number from raw data.
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SYNOPSIS
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--------
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[verse]
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--
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*#include <event-parse.h>*
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int *tep_read_number_field*(struct tep_format_field pass:[*]_field_, const void pass:[*]_data_, unsigned long long pass:[*]_value_);
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--
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DESCRIPTION
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-----------
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The _tep_read_number_field()_ function reads the value of the _field_ from the
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raw _data_ and stores it in the _value_. The function sets the _value_ according
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to the endianness of the raw data and the current machine and stores it in
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_value_.
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RETURN VALUE
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------------
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The _tep_read_number_field()_ function retunrs 0 in case of success, or -1 in
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case of an error.
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EXAMPLE
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-------
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[source,c]
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--
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#include <event-parse.h>
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...
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struct tep_handle *tep = tep_alloc();
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...
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struct tep_event *event = tep_find_event_by_name(tep, "timer", "hrtimer_start");
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...
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void process_record(struct tep_record *record)
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{
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unsigned long long pid;
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struct tep_format_field *field_pid = tep_find_common_field(event, "common_pid");
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if (tep_read_number_field(field_pid, record->data, &pid) != 0) {
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/* Failed to get "common_pid" value */
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}
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}
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...
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--
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FILES
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-----
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[verse]
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--
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*event-parse.h*
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Header file to include in order to have access to the library APIs.
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*-ltraceevent*
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Linker switch to add when building a program that uses the library.
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--
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SEE ALSO
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--------
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_libtraceevent(3)_, _trace-cmd(1)_
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AUTHOR
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------
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[verse]
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--
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*Steven Rostedt* <rostedt@goodmis.org>, author of *libtraceevent*.
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*Tzvetomir Stoyanov* <tz.stoyanov@gmail.com>, author of this man page.
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--
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REPORTING BUGS
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--------------
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Report bugs to <linux-trace-devel@vger.kernel.org>
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LICENSE
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-------
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libtraceevent is Free Software licensed under the GNU LGPL 2.1
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RESOURCES
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---------
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https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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