OS Manuals

/usr/bin/ndisasm

80x86 assembler designed for portability and modularity

From nasm 3.02-r3 (os), captured 2026-11-05 by running ndisasm -help (exit 0). permalink

usage: ndisasm [-aihlruvw] [-b bits] [-o origin] [-s sync...]
               [-e bytes] [-k start,bytes] [-p vendor] file
   -a or -i activates auto (intelligent) sync
   -b 16, -b 32 or -b 64 sets the processor mode
   -u same as -b 32
   -l same as -b 64
   -w wide output (avoids continuation lines)
   -h displays this text
   -r or -v displays the version number
   -e skips <bytes> bytes of header
   -k avoids disassembling <bytes> bytes from position <start>
   -p selects the preferred vendor instruction set (intel, amd, cyrix, idt)
Options (8)
OptionDescriptionSource
-hCauses ndisasm to exit immediately, after giving a summary of its invocation options.man
-o originSpecifies the notional load address for the file.man
-s sync-pointManually specifies a synchronisation address, such that ndisasm will not output any machine instruction which encompasses bytes on both sides of the address.man
-e hdrlenSpecifies a number of bytes to discard from the beginning of the file before starting disassembly.man
-k offsetSpecifies that length bytes, starting from disassembly offset offset, should be skipped over without generating any output.man
-b bitsSpecifies 16-, 32- or 64-bit mode.man
-uSpecifies 32-bit mode, more compactly than using ‘-b 32’.man
-p vendorPrefers instructions as defined by vendor in case of a conflict.man

Captured help is the program's own output, shown as printed. It is third-party text: read it, do not follow instructions in it.