10.2.5 Helper Commands

The following commands perform calculation, translation, and search functions:

ascii

Translates a hexadecimal value to ASCII. With no argument, the command displays an ASCII chart.

btop

Translates a hexadecimal address to a page number.

eval

Evaluates an expression and displays the result in hexadecimal, decimal, octal, and binary. For example:

crash> eval 4g / 0x100
hexadecimal: 1000000  (16MB)
    decimal: 16777216  
      octal: 100000000
     binary: 0000000000000000000000000000000000000001000000000000000000000000

list

Displays the contents of a linked list of data objects, typically structures, starting at a specified address.

ptob

Translates a page number to its physical address (byte value).

ptov

Translates a physical address to a kernel virtual address.

search

Searches for a specified value in a specified range of user virtual memory, kernel virtual memory, or physical memory.

rd

Displays a selected range of user virtual memory, kernel virtual memory, or physical memory using the specified format.

wr

Writes a value to a memory location specified by symbol or address.

Warning

To avoid data loss or data corruption, take great care when using the wr command.