During the execution of a command file or a user-defined command, normal
gdb output is suppressed; the only output that appears is what is
explicitly printed by the commands in the definition. This section
describes three commands useful for generating exactly the output you
want.
echo text
Print text. Nonprinting characters can be included in
text using C escape sequences, such as \n to print a
newline. No newline is printed unless you specify one.
In addition to the standard C escape sequences, a backslash followed
by a space stands for a space. This is useful for displaying a
string with spaces at the beginning or the end, since leading and
trailing spaces are otherwise trimmed from all arguments.
To print and foo = , use the command
echo \ and foo = \ .
A backslash at the end of text can be used, as in C, to continue
the command onto subsequent lines. For example,
echo This is some text\n\
which is continued\n\
onto several lines.\n
produces the same output as
echo This is some text\n
echo which is continued\n
echo onto several lines.\n
output expression
Print the value of expression and nothing but that value: no
newlines, no $nn = . The value is not entered in the
value history either.
Refer to Section 10.1 Expressions, for more information
on expressions.
output/fmtexpression
Print the value of expression in format fmt. You can use
the same formats as for print.
Refer to Section 10.4 Output formats, for more information.
printf string, expressions…
Print the values of the expressions under the control of
string. The expressions are separated by commas and may be
either numbers or pointers. Their values are printed as specified by
string, exactly as if your program were to execute the C
subroutine
printf (string, expressions…);
For example, you can print two values in hex like this:
