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NAME |SYNOPSIS |DESCRIPTION |RETURN VALUE |EXAMPLE |FILES |SEE ALSO |AUTHOR |REPORTING BUGS |LICENSE |RESOURCES |NOTES |COLOPHON | |
LIBTRACEEVENT(3) libtraceevent ManualLIBTRACEEVENT(3)tep_print_field_content, tep_print_fields, tep_print_num_field, tep_print_func_field, tep_record_print_fields, tep_record_print_selected_fields - Print the field content.
#include <event-parse.h>#include <trace-seq.h> voidtep_print_field_content(struct trace_seq *s, void *data, int size, struct tep_format_field *field); voidtep_print_fields(struct trace_seq *s, void *data, intsize, struct tep_event *event); inttep_print_num_field(struct trace_seq *s, const char *fmt, struct tep_event *event, const char *name, struct tep_record *record, interr); inttep_print_func_field(struct trace_seq *s, const char *fmt, struct tep_event *event, const char *name, struct tep_record *record, interr); voidtep_record_print_fields(struct trace_seq *s, struct tep_record *record, struct tep_event *event); voidtep_record_print_selected_fields(struct trace_seq *s, struct tep_record *record, struct tep_event *event, intselect_mask);
These functions print recorded field’s data, according to the field’s type. Thetep_print_field_content()function extracts from the recorded rawdata value of thefield and prints it intos, according to the field type. Thetep_print_fields()prints each field name followed by the record’s field value according to the field’s type: "field1_name=field1_value field2_name=field2_value ..." It iterates all fields of theevent, and callstep_print_field_content()for each of them. Thetep_print_num_field()function prints a numeric field with given format string. A search is performed in theevent for a field withname. If such field is found, its value is extracted from therecord and is printed in thes, according to the given format stringfmt. If the argumenterr is non-zero, and an error occures - it is printed in thes. Thetep_print_func_field()function prints a function field with given format string. A search is performed in theevent for a field withname. If such field is found, its value is extracted from therecord. The value is assumed to be a function address, and a search is perform to find the name of this function. The function name (if found) and its address are printed in thes, according to the given format stringfmt. If the argumenterr is non-zero, and an error occures - it is printed ins. Thetep_record_print_fields()prints the field’s name followed by its value for all record’s field. Thetep_record_print_selected_fields()prints the field’s name followed by its value for selected subset of record field. The fields to be printed are defined by theselect_mask bit mask.
Thetep_print_num_field()andtep_print_func_field()functions return 1 on success, -1 in case of an error or 0 if the print buffers is full.
#include <event-parse.h> #include <trace-seq.h> ... struct tep_handle *tep = tep_alloc(); ... struct trace_seq seq; trace_seq_init(&seq); struct tep_event *event = tep_find_event_by_name(tep, "timer", "hrtimer_start"); ... void process_record(struct tep_record *record) { struct tep_format_field *field_pid = tep_find_common_field(event, "common_pid"); trace_seq_reset(&seq); /* Print the value of "common_pid" */ tep_print_field_content(&seq, record->data, record->size, field_pid); /* Print all fields of the "hrtimer_start" event */ tep_print_fields(&seq, record->data, record->size, event); /* Print the value of "expires" field with custom format string */ tep_print_num_field(&seq, " timer expires in %llu ", event, "expires", record, 0); /* Print the address and the name of "function" field with custom format string */ tep_print_func_field(&seq, " timer function is %s ", event, "function", record, 0); } ...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.
libtraceevent(3),trace-cmd(1)
Steven Rostedt<rostedt@goodmis.org[1]>, author oflibtraceevent.Tzvetomir Stoyanov<tz.stoyanov@gmail.com[2]>, author of this man page.
Report bugs to <linux-trace-devel@vger.kernel.org[3]>
libtraceevent is Free Software licensed under the GNU LGPL 2.1
https://git.kernel.org/pub/scm/libs/libtrace/libtraceevent.git/
1. rostedt@goodmis.org mailto:rostedt@goodmis.org 2. tz.stoyanov@gmail.com mailto:tz.stoyanov@gmail.com 3. linux-trace-devel@vger.kernel.org mailto:linux-trace-devel@vger.kernel.org
This page is part of thelibtraceevent (Linux kernel trace event library) project. Information about the project can be found at ⟨https://www.trace-cmd.org/⟩. If you have a bug report for this manual page, see ⟨https://www.trace-cmd.org/⟩. This page was obtained from the project's upstream Git repository ⟨https://git.kernel.org/pub/scm/libs/libtrace/libtraceevent.git⟩ on 2025-08-11. (At that time, the date of the most recent commit that was found in the repository was 2025-05-30.) If you discover any rendering problems in this HTML version of the page, or you believe there is a better or more up-to-date source for the page, or you have corrections or improvements to the information in this COLOPHON (which isnot part of the original manual page), send a mail to man-pages@man7.orglibtraceevent 1.7.3 09/24/2023LIBTRACEEVENT(3)HTML rendering created 2025-09-06 byMichael Kerrisk, author ofThe Linux Programming Interface. For details of in-depthLinux/UNIX system programming training courses that I teach, lookhere. Hosting byjambit GmbH. | |