72 Chapter 10. Examining Datadisable display dnums...Disable the display of item numbers dnums. A disabled display item is not printed automatically,but is not forgotten. It may be enabled again later.enable display dnums...Enable display of item numbers dnums. It becomes effective once again in auto display of itsexpression, until you specify otherwise.displayDisplay the current values of the expressions on the list, just as is done when your program stops.info displayPrint the list of expressions previously set up to display automatically, each one with its itemnumber, but without showing the values. This includes disabled expressions, which are markedas such. It also includes expressions which would not be displayed right now because they referto automatic variables not currently available.If a display expression refers to local variables, then it does not make sense outside the lexical contextfor which it was set up. Such an expression is disabled when execution enters a context where one ofits variables is not defined. For example, if you give the command display last_char while insidea function with an argument last_char, gdb displays this argument while your program continues tostop inside that function. When it stops elsewhere--where there is no variable last_char--the displayis disabled automatically. The next time your program stops where last_char is meaningful, youcan enable the display expression once again.10.7. Print settingsgdb provides the following ways to control how arrays, structures, and symbols are printed.These settings are useful for debugging programs in any language:set print addressset print address on{No value for ‘ listitem>GDBN’} prints memory addresses showing the location of stacktraces, structure values, pointer values, breakpoints, and so forth, even when it also displays thecontents of those addresses. The default is on. For example, this is what a stack frame displaylooks like with set print address on:(gdb) f#0 set_quotes (lq=0x34c78 " ", rq=0x34c88 " ")at input.c:530530 if (lquote != def_lquote)set print address offDo not print addresses when displaying their contents. For example, this is the same stack framedisplayed with set print address off:(gdb) set print addr off(gdb) f#0 set_quotes (lq=" ", rq=" ") at input.c:530530 if (lquote != def_lquote)
