.data
inChar: .fill 1
outChar: .fill 1

.text
.global _start
_start:

readOneLine:
  # read a character from stdin
  movl $3, %eax # sys service 3 for reading
  movl $0, %ebx # stdin is file handle 0
  movl $inChar, %ecx # address of where to read to
  movl $1, %edx # number of bytes to read
  
  int  $0x80    # request the OS to perform the operation
  
  # check if we are at eof
  cmpl $0, %eax
  jz   allDone
  
  # it is not eof, something was read into inChar
  cmpb $'\n',inChar # compare to end of line
  jz   gotEOLN
  # not end of line
  
  # do some processing here 
  jmp  readOneLine
  
gotEOLN:
  # process the number read here
  movb $'?',outChar
  movl $4, %eax
  movl $1, %ebx
  movl $outChar, %ecx
  movl $1, %edx
  
  int  $0x80
  jmp  readOneLine
  
  
allDone:  


  movl $1, %eax
  movl $0, %ebx
  int  $0x80