INTERACTIVE ASSEMBLY

This script uses GNU assembler, objdump and grep to
assemble one or more assembly instructions provided
via standard input.

The actual programs used are declared by the AS and
OBJDUMP environment variables, and feature the
default values of "as" and "objdump" respectively.

If you wish to use different implementations, such
as those that have been built by GNU binutils as a
part of a cross-compilation toolchain, then define
the AS, ASFLAGS and OBJDUMP environment variables
accordingly.

The AS output (or OBJDUMP input) file is specified 
by OUTPUT, and has a default value of "/tmp/a.out".


DEFAULT USAGE (ASSUMING A LINUX/x86-64 HOST)

  $ ./ias

  incl %esi; decl %ecx
     0:   ff c6                   inc    %esi
     2:   ff c9                   dec    %ecx

  movq %rax, 0x08(%rsp)
     0:   48 89 44 24 08          mov    %rax,0x8(%rsp)
  
  syscall
     0:   0f 05                   syscall 

  ^D


USER-DEFINED AS AND OBJDUMP

  $ AS=arm-linux-gnueabihf-as \
    OBJDUMP=arm-linux-gnueabihf-objdump \
    ./ias

  ldmia sp!, {r3, r4, r5, r6, r7, r8, r9, pc}          
     0:   e8bd83f8        pop     {r3, r4, r5, r6, r7, r8, r9, pc}
  
  movs r0, #10
     0:   e3b0000a        movs    r0, #10
  
  ^D


USER-DEFINED AS, ASFLAGS AND OBJDUMP

  $ AS=arm-linux-gnueabihf-as ASFLAGS=-mthumb \
    OBJDUMP=arm-linux-gnueabihf-objdump \
    ./ias

  pop     {r7, pc}
     0:   bd80            pop     {r7, pc}
  
  movs    r0, #10
     0:   200a            movs    r0, #10

  ^D