Sprite 1984 - 1993/Sprite 1984 - 1993.iso/man/cmds.fmt/gdb.new.man

Text File | 1992-06-09 | 9.4 KB | 331 lines

gdb                       User Commands                       gdb



NNAAMMEE
     gdb - The GNU Debugger

SSYYNNOOPPSSIISS
     ggddbb  [--hheellpp] [--nnxx] [--qq] [--bbaattcchh] [--ccdd==_d_i_r] [--ff] [--bb _b_p_s]
          [--ttttyy==_d_e_v] [--ss _s_y_m_f_i_l_e] [--ee _p_r_o_g] [--ssee _p_r_o_g] [--cc _c_o_r_e]
          [--xx _c_m_d_s] [--dd _d_i_r] [_p_r_o_g[_c_o_r_e|_p_r_o_c_I_D]]

DDEESSCCRRIIPPTTIIOONN
     The purpose of a debugger such as GDB is to allow you to see
     what  is  going  on  ``inside''  another  program  while  it
     executes-or what another program was doing at the moment  it
     crashed.

     GDB can do four main kinds of things (plus other  things  in
     support of these) to help you catch bugs in the act:


        o+ Start your  program,  specifying  anything  that  might
          affect its behavior.


        o+ Make your program stop on specified conditions.


        o+ Examine  what  has  happened,  when  your  program  has
          stopped.


        o+ Change things in your program, so  you  can  experiment
          with  correcting  the  effects  of one bug and go on to
          learn about another.

     You can use GDB to debug programs written  in  C,  C++,  and
     Modula-2.   Fortran support will be added when a GNU Fortran
     compiler is ready.

     GDB is invoked with the shell command ggddbb.  Once started, it
     reads  commands  from the terminal until you tell it to exit
     with the GDB command qquuiitt.  You can get online help from ggddbb
     itself by using the command hheellpp.

     You can run ggddbb with no arguments or options; but  the  most
     usual way to start GDB is with one argument or two, specify-
     ing an executable program as the argument:

     gdb program


     You can also start with both an  executable  program  and  a
     core file specified:




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     gdb program core


     You can, instead, specify a process ID as a second argument,
     if you want to debug a running process:

     gdb program 1234


     would attach GDB to process 11223344 (unless  you  also  have  a
     file named `11223344'; GDB does check for a core file first).

     Here are some of the most frequently needed GDB commands:

     bbrreeaakk [_f_i_l_e::]_f_u_n_c_t_i_o_n
           Set a breakpoint at _f_u_n_c_t_i_o_n (in _f_i_l_e).

     rruunn [_a_r_g_l_i_s_t]
          Start your program (with _a_r_g_l_i_s_t, if specified).

     bbtt   Backtrace: display the program stack.

     pprriinntt _e_x_p_r
           Display the value of an expression.

     cc    Continue running your program (after stopping, e.g.  at
          a breakpoint).

     nneexxtt Execute next program line (after stopping);  step  _o_v_e_r
          any function calls in the line.

     sstteepp Execute next program line (after stopping);  step  _i_n_t_o
          any function calls in the line.

     hheellpp [_n_a_m_e]
          Show information about GDB  command  _n_a_m_e,  or  general
          information about using GDB.

     qquuiitt Exit from GDB.

     For full details on GDB, see _U_s_i_n_g _G_D_B: _A _G_u_i_d_e _t_o  _t_h_e  _G_N_U
     _S_o_u_r_c_e-_L_e_v_e_l  _D_e_b_u_g_g_e_r, by Richard M. Stallman and Roland H.
     Pesch.  The same text is available online as the  ggddbb  entry
     in the iinnffoo program.

OOPPTTIIOONNSS
     Any arguments other than options specify an executable  file
     and  core  file (or process ID); that is, the first argument
     encountered with no associated option flag is equivalent  to
     a  `--ssee'  option, and the second, if any, is equivalent to a
     `--cc' option if it's the name of a file.  Many  options  have
     both  long  and  short forms; both are shown here.  The long



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     forms are also recognized if you truncate them, so  long  as
     enough  of the option is present to be unambiguous.  (If you
     prefer, you can flag option arguments with `++'  rather  than
     `--', though we illustrate the more usual convention.)

     All the options and command line arguments you give are pro-
     cessed  in  sequential  order.  The order makes a difference
     when the `--xx' option is used.


     --hheellpp

     --hh   List all options, with brief explanations.


     --ssyymmbboollss==_f_i_l_e

     --ss _f_i_l_e
           Read symbol table from file _f_i_l_e.


     --eexxeecc==_f_i_l_e

     --ee _f_i_l_e
           Use file _f_i_l_e as the executable file to  execute  when
          appropriate, and for examining pure data in conjunction
          with a core dump.


     --ssee==_f_i_l_e
           Read symbol table from file _f_i_l_e and  use  it  as  the
          executable file.


     --ccoorree==_f_i_l_e

     --cc _f_i_l_e
           Use file _f_i_l_e as a core dump to examine.


     --ccoommmmaanndd==_f_i_l_e

     --xx _f_i_l_e
           Execute GDB commands from file _f_i_l_e.


     --ddiirreeccttoorryy==_d_i_r_e_c_t_o_r_y

     --dd _d_i_r_e_c_t_o_r_y
           Add _d_i_r_e_c_t_o_r_y to the path to search for source files.

     --nnxx



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     --nn   Do not execute commands from any `..ggddbbiinniitt' initializa-
          tion  files.  Normally, the commands in these files are
          executed after all the command  options  and  arguments
          have been processed.



     --qquuiieett

     --qq   ``Quiet''.  Do not print the introductory and copyright
          messages.   These messages are also suppressed in batch
          mode.


     --bbaattcchh
          Run in batch mode.  Exit with status 00 after processing
          all   the   command  files  specified  with  `--xx'  (and
          `..ggddbbiinniitt',  if  not  inhibited).   Exit  with  nonzero
          status if an error occurs in executing the GDB commands
          in the command files.

          Batch mode may be useful for running GDB as  a  filter,
          for  example  to  download and run a program on another
          computer; in order to make this more useful,  the  mes-
          sage

          Program exited normally.


          (which is ordinarily issued whenever a program  running
          under  GDB  control terminates) is not issued when run-
          ning in batch mode.


     --ccdd==_d_i_r_e_c_t_o_r_y
           Run GDB using  _d_i_r_e_c_t_o_r_y  as  its  working  directory,
          instead of the current directory.


     --ffuullllnnaammee

     --ff   Emacs sets this option when it runs GDB  as  a  subpro-
          cess.   It  tells  GDB to output the full file name and
          line number in a standard,  recognizable  fashion  each
          time  a  stack  frame is displayed (which includes each
          time the  program  stops).   This  recognizable  format
          looks  like  two ` 3322' characters, followed by the file
          name, line number and character position  separated  by
          colons, and a newline.  The Emacs-to-GDB interface pro-
          gram uses the two  ` 3322'  characters  as  a  signal  to
          display the source code for the frame.




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     --bb _b_p_s
           Set the line speed (baud rate or bits per  second)  of
          any serial interface used by GDB for remote debugging.


     --ttttyy==_d_e_v_i_c_e
           Run using _d_e_v_i_c_e for your program's standard input and
          output.

SSEEEE AALLSSOO
     `ggddbb' entry in iinnffoo; _U_s_i_n_g _G_D_B: _A _G_u_i_d_e _t_o _t_h_e  _G_N_U  _S_o_u_r_c_e-
     _L_e_v_e_l  _D_e_b_u_g_g_e_r,  Richard  M.  Stallman and Roland H. Pesch,
     July 1991.

CCOOPPYYIINNGG
     Copyright (c) 1991 Free Software Foundation, Inc.

     Permission is granted to make and distribute verbatim copies
     of  this  manual provided the copyright notice and this per-
     mission notice are preserved on all copies.

     Permission is granted to copy and distribute  modified  ver-
     sions of this manual under the conditions for verbatim copy-
     ing, provided that the entire resulting derived work is dis-
     tributed under the terms of a permission notice identical to
     this one.

     Permission is granted to copy and distribute translations of
     this  manual  into  another language, under the above condi-
     tions for modified versions,  except  that  this  permission
     notice  may be included in translations approved by the Free
     Software Foundation instead of in the original English.























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