This is a short Morse code decoder written as a shellscript using sed.

The Morse coded text should be in $text, and should be written with spaces between the letters.

echo $text\  | tr . 0 | sed -e {s/0----\ /1/g} -e {s/00---\ /2/g} -e {s/000--\ /3/g} -e {s/000-\ /4/g} -e {s/00000\ /5/g} -e {s/-0000\ /6/g} -e {s/--000\ /7/g} -e {s/---00\ /8/g} -e {s/----0\ /9/g} -e {s/-----\ /0/g} \
	| sed -e {s/-0-0\ /c/g} -e {s/-000\ /b/g} -e {s/00-0\ /f/g} -e {s/0000\ /h/g} -e {s/0---\ /j/g} -e {s/0-00\ /l/g} -e {s/0--0\ /p/g} -e {s/--0-\ /q/g} -e {s/000-\ /v/g} -e {s/-00-\ /x/g} -e {s/-0--\ /y/g} -e {s/--00\ /z/g} \
	| sed -e {s/0--\ /w/g} -e {s/-00\ /d/g} -e {s/--0\ /g/g} -e {s/-0-\ /k/g} -e {s/---\ /o/g} -e {s/0-0\ /r/g} -e {s/000\ /s/g} -e {s/00-\ /u/g} \
	| sed -e {s/0-\ /a/g} -e {s/00\ /i/g} -e {s/--\ /m/g} -e {s/-0\ /n/g} \
	| sed -e {s/0\ /e/g} -e {s/-\ /t/g}

NASM code for writing the integer in eax to stdout.

segment .bss
        writeTemp       resb    10

segment .text
_writeln:                               
        MOV     ebx,    eax             ; Number is already in eax
        MOV     ecx,    10
        XOR     edi,    edi
L0:
        CMP     eax,    0
        JE      L1
        ADD     edi,    1
        XOR     edx,    edx
        IDIV    ecx
        JMP     L0
L1:
        ADD     edi,    writeTemp       ; Length of the number is in edi
        MOV     esi,    edi
        MOV byte        [edi],  10      ; Add a newline
        SUB     edi,    1
        XOR     eax,    eax
L2:                             
        CMP     ebx,    0
        JE      L3
        MOV     eax,    ebx
        XOR     edx,    edx
        IDIV    ecx
        ADD     dl,     48
        MOV     [edi],  dl
        SUB     edi,    1
        MOV     ebx,    eax
        JMP     L2                      ; Number has been written to writeTemp from tail to head
L3:                             
        MOV     eax,    4
        MOV     ebx,    1
        MOV     ecx,    writeTemp
        MOV     edx,    esi
        SUB     edx,    writeTemp
        ADD     edx,    1
        INT     80h

The canonical Hello World program in assambler.

Compile it with:
nasm -f elf hello.s
ld -s -o hello hello.o

Helloworld is a function. It uses the write system call to print to stdout (file descriptor 1).

This is written in NASM (Intel) syntax, hence it will not work with gas, tasm or masm. It was written for Linux. The details may vary on other platforms.

Download NASM for free at http://nasm.sourceforge.net/

section .data
  hello: db "Hello world!",10
  hellolen: equ $ - hello

section .text
  global _start

_start:
  call helloworld

  mov eax,1 ; start exit procedure
  mov ebx,0

  int 80h

helloworld:
  mov eax,4 ; 4 is the code for the write system call
  mov ebx,1 ; 1 is the fd for stdout
  mov ecx,hello ; the address of the string
  mov edx,hellolen ; the length of the string

  int 80h ; trigger an interrupt; this should be 21h for DOS

  ret