Debugging with GDB: Numbers

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22.5 Numbers

You can always enter numbers in octal, decimal, or hexadecimal in GDB by the usual conventions: octal numbers begin with ‘0’, decimal numbers end with ‘.’, and hexadecimal numbers begin with ‘0x’. Numbers that neither begin with ‘0’ or ‘0x’, nor end with a ‘.’ are, by default, entered in base 10; likewise, the default display for numbers—when no particular format is specified—is base 10. You can change the default base for both input and output with the commands described below.

set input-radix base

Set the default base for numeric input. Supported choices for base are decimal 8, 10, or 16. The base must itself be specified either unambiguously or using the current input radix; for example, any of

set input-radix 012
set input-radix 10.
set input-radix 0xa

sets the input base to decimal. On the other hand, ‘set input-radix 10’ leaves the input radix unchanged, no matter what it was, since ‘10’, being without any leading or trailing signs of its base, is interpreted in the current radix. Thus, if the current radix is 16, ‘10’ is interpreted in hex, i.e. as 16 decimal, which doesn’t change the radix.

set output-radix base

Set the default base for numeric display. Supported choices for base are decimal 8, 10, or 16. The base must itself be specified either unambiguously or using the current input radix.

show input-radix

Display the current default base for numeric input.

show output-radix

Display the current default base for numeric display.

set radix [ base ]

show radix

These commands set and show the default base for both input and output of numbers. set radix sets the radix of input and output to the same base; without an argument, it resets the radix back to its default value of 10.

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