After you have a profile data file `gmon.out', you can run
to interpret the information in it. The
gprof program prints a
flat profile and a call graph on standard output. Typically you would
redirect the output of
gprof into a file with `>'.
gprof like this:
gprof options [executable-file [profile-data-files...]] [> outfile]
Here square-brackets indicate optional arguments.
If you omit the executable file name, the file `a.out' is used. If you give no profile data file name, the file `gmon.out' is used. If any file is not in the proper format, or if the profile data file does not appear to belong to the executable file, an error message is printed.
You can give more than one profile data file by entering all their names after the executable file name; then the statistics in all the data files are summed together.
The following options may be used to selectively include or exclude functions in the output:
gprofto suppress the printing of statically declared (private) functions. (These are functions whose names are not listed as global, and which are not visible outside the file/function/block where they were defined.) Time spent in these functions, calls to/from them, etc, will all be attributed to the function that was loaded directly before it in the executable file. This option affects both the flat profile and the call graph.
gprofto not print information about the function function_name (and its children...) in the call graph. The function will still be listed as a child of any functions that call it, but its index number will be shown as `[not printed]'. More than one `-e' option may be given; only one function_name may be indicated with each `-e' option.
-E functionoption works like the
-eoption, but time spent in the function (and children who were not called from anywhere else), will not be used to compute the percentages-of-time for the call graph. More than one `-E' option may be given; only one function_name may be indicated with each `-E' option.
gprofto limit the call graph to the function function_name and its children (and their children...). More than one `-f' option may be given; only one function_name may be indicated with each `-f' option.
-foption, but only time spent in the function and its children (and their children...) will be used to determine total-time and percentages-of-time for the call graph. More than one `-F' option may be given; only one function_name may be indicated with each `-F' option. The `-F' option overrides the `-E' option.
-k from... to...
gprofto print the current version number, and then exit.
gprofwill mention all functions in the flat profile, even those that were never called, and that had no time spent in them. This is useful in conjunction with the `-c' option for discovering which routines were never called.
The order of these options does not matter.
Note that only one function can be specified with each
-F option. To specify more than one
function, use multiple options. For example, this command:
gprof -e boring -f foo -f bar myprogram > gprof.output
lists in the call graph all functions that were reached from either
bar and were not reachable from
There are a few other useful
gprofdoesn't print the verbose blurbs that try to explain the meaning of all of the fields in the tables. This is useful if you intend to print out the output, or are tired of seeing the blurbs.
gprofto summarize the information in the profile data files it read in, and write out a profile data file called `gmon.sum', which contains all the information from the profile data files that
gprofread in. The file `gmon.sum' may be one of the specified input files; the effect of this is to merge the data in the other input files into `gmon.sum'. See section Statistical Inaccuracy of
gprofOutput. Eventually you can run
gprofagain without `-s' to analyze the cumulative data in the file `gmon.sum'.
gprofto print its output in "traditional" BSD style.