For the ‘ i ’ format, the unit size is ignored and is normally not written For the ‘ s ’ format, the unit size defaults to ‘ b ’, unless it is explicitly given Info breakpoints (to the address of the last breakpoint listed), info line (to the starting address of a line), and print (if you use it to display a value from memory). It specifies how much memory (counting by units u) to display The default is `x' (hexadecimal) initially, or the format from the last time you used either x or print The unit size is any of
When using x/100c, the output shows the both ascii and decimal 40 '(' 40 '(' how can gdb show the ascii and hex at the same time 0x28 'c' 0x28 'c' this format is This page explains the x command The x command displays the memory contents at a given address using the specified format. Printf format, var1, var2,… — display the values of var1, var2,…
R — begin execution of a program that has been loaded under control of gdb X/ nfs memoryaddress — display (examine) n values in memory in format f of size s starting at memoryaddress. The encoding is set by the programming language and cannot be altered Addr, starting display address addr is the address where you want gdb to begin displaying memory The expression need not have a pointer value (though it may) It is always interpreted as an integer address of a byte of memory
See expressions, for more information on. Output formats (debugging with gdb)by default, gdb prints a value according to its data type Sometimes this is not what you want For example, you might want to print a number in hex, or a pointer in decimal Or you might want to view data in memory at a certain address as a character string or as an instruction To do these things, specify an output format when you print a value.
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