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## read a character from stdin, save it to a global, write it to stdout
#
# To run (from the subx directory):
# $ subx translate examples/ex4.subx -o examples/ex4
# $ subx run examples/ex4
== code
# read(stdin, x, 1)
# fd = 0 (stdin)
bb/copy-to-EBX 0/imm32
# initialize x (location to write result to)
b9/copy-to-ECX x/imm32
# size = 1 character
ba/copy-to-EDX 1/imm32
# read(fd, x, size)
b8/copy-to-EAX 3/imm32/read
cd/syscall 0x80/imm8
# write(stdout, x, 1)
# fd = 1 (stdout)
bb/copy-to-EBX 1/imm32
# initialize x (location to read from)
b9/copy-to-ECX x/imm32
# size = 1 character
ba/copy-to-EDX 1/imm32
# write(fd, x, size)
b8/copy-to-EAX 4/imm32/write
cd/syscall 0x80/imm8
# exit(EBX)
b8/copy-to-EAX 1/imm32/exit
cd/syscall 0x80/imm8
== data
x:
00 00 00 00 # space for read() to write to
# vim:nowrap:textwidth=0
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