Red Hat ENTERPRISE LINUX 3 - DEVELOPER TOOLS GUIDE Guide de l'utilisateur télécharger pdf (Page 65)

Running GDB

The execution of a stopped program can be resumed in a number of ways. The following are the most

common.

c (continue)

The continue command simply restarts the execution of the program, which will continue to

execute until it encounters a breakpoint, runs into a specified or emergent condition (e.g. an error),

or terminates.

n (next)

Like continue, the next command also restarts execution; however, in addition to the stopping

conditions implicit in the continue command, next will also halt execution at the next sequential

line of code in the current source file.

s (step)

Like next, the step command also halts execution at each sequential line of code in the current

source file. However, if execution is currently stopped at a source line containing a function call,

GDB stops execution after entering the function call (rather than executing it).

fini (finish)

Like the aforementioned commands, the finish command resumes executions, but halts when

execution returns from a function.

Finally, two essential commands:

q (quit)

This terminates the execution.

h (help)

The help command provides access to its extensive internal documentation. The command

takes arguments: help breakpoint (or h br), for example, shows a detailed description

of the breakpoint command. Refer to the help output of each command for more detailed

information.

5.2.2. Running GDB

This section will describe a basic execution of GDB, using the following simple program:

hello.c

#include <stdio.h>

char hello[] = { "Hello, World!" };

int

main()

{

fprintf (stdout, "%s\n", hello);

return (0);

}

The following procedure illustrates the debugging process in its most basic form.

Procedure 5.1. Debugging a 'Hello World' Program

1. Compile hello.c into an executable with the debug flag set, as in:

gcc -g -o hello hello.c

1 2 ... 60 61 62 63 64 65 66 67 68 69 70 ... 99 100

Pas de commentaire

Red Hat ENTERPRISE LINUX 3 - DEVELOPER TOOLS GUIDE Guide de l'utilisateur Page 65