SYNOPSIS
#include <event-parse.h> #include <trace-seq.h> void trace_seq_init(struct trace_seq *s); void trace_seq_destroy(struct trace_seq *s); void trace_seq_reset(struct trace_seq *s); void trace_seq_terminate(struct trace_seq *s); int trace_seq_putc(struct trace_seq *s, unsigned char c); int trace_seq_puts(struct trace_seq *s, const char *str); int trace_seq_printf(struct trace_seq *s, const char *fmt, …); int trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args); int trace_seq_do_printf(struct trace_seq *s); int trace_seq_do_fprintf(struct trace_seq *s, FILE *fp);
DESCRIPTION
Trace sequences are used to allow a function to call several other functions to create a string of data to use.
The trace_seq_init() function initializes the trace sequence s.
The trace_seq_destroy() function destroys the trace sequence s and frees all its resources that it had used.
The trace_seq_reset() function re-initializes the trace sequence s. All characters already written in s will be deleted.
The trace_seq_terminate() function terminates the trace sequence s. It puts the null character '\0' at the end of the buffer.
The trace_seq_putc() function puts a single character c in the trace sequence s.
The trace_seq_puts() function puts a NULL terminated string str in the trace sequence s.
The trace_seq_printf() function puts a formated string fmt _with variable arguments _… in the trace sequence s.
The trace_seq_vprintf() function puts a formated string fmt _with list of arguments _args in the trace sequence s.
The trace_seq_do_printf() function prints the buffer of trace sequence s to the standard output stdout.
The trace_seq_do_fprintf() function prints the buffer of trace sequence s to the given file fp.
RETURN VALUE
Both trace_seq_putc() and trace_seq_puts() functions return the number of characters put in the trace sequence, or 0 in case of an error
Both trace_seq_printf() and trace_seq_vprintf() functions return 0 if the trace oversizes the buffer’s free space, the number of characters printed, or a negative value in case of an error.
Both trace_seq_do_printf() and trace_seq_do_fprintf() functions return the number of printed characters, or -1 in case of an error.
EXAMPLE
FILES
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.
-ltraceevent
Linker switch to add when building a program that uses the library.
SEE ALSO
libtraceevent(3), trace-cmd(1)
AUTHOR
Steven Rostedt <rostedt@goodmis.org>, author of libtraceevent. Tzvetomir Stoyanov <tz.stoyanov@gmail.com>, author of this man page.
REPORTING BUGS
Report bugs to <linux-trace-devel@vger.kernel.org>
LICENSE
libtraceevent is Free Software licensed under the GNU LGPL 2.1