D.1. Introduction

One way to obtain useful information about the execution of a program is to use the GNU profiler utility gprof . This utility, which is part of most standard Linux installations, provides information on functions your program calls. By analyzing the data it provides, you can often improve the execution speed of a program by revising slow, inefficient sections of code. Additionally, profiling may illuminate bugs that may not have surfaced. The following sections present an overview of how to use gprof . Interested readers seeking additional information on this utility are encouraged to read the manual page for the utility and to visit the official GNU website (www.gnu.org) and peruse the full set of online documentation on gprof .

Profiling a program is a three-step process:

1. The program is compiled and linked with profiling enabled.
2. The executable version of the program is run to generate a special profile data file.
3. The gprof utility is used to analyze and display the profiling data.