4 ms·

Inline C/Assembler in Bash

106 points by eklitzke 10y ago

tehrei 10y ago
while read line; do echo $line>>$cfile done Okay, I know this is a joke and all, but that's the exact wrong way to do it. What you want to do is just cat > $cfile
ob 10y ago
> Has you ever wanted to combine the speed and safety of Bash with the raw, unbridled power of C? Uh, no? :)
susanthesquark 10y ago
this is cool do more
unsignedqword 10y ago
The insane things people do in Bash sometimes...although I don't think anything can top the x86 Assembler that was written entirely in Bash: http://lists.gnu.org/archive/html/bug-bash/2001-02/msg00054.html http://lists.gnu.org/archive/html/bug-bash/2001-02/msg00054....
- ravenstine 10y ago
  Neat!
- skynetv2 10y ago
  why ....
  - mikestew 10y ago
    Click the link, and you're just a few spacebar presses away from answering that question for yourself (it's a few paragraphs down).
    - kevincox 10y ago
      > It just continuously cracks me up. My favourite of the listed reasons.
- foxhill 10y ago
  to call this an assembler is to not give it credit where it's due - this is not an assembler, it's much more than that. it's a set of functions for bash that when sourced make the assembly a valid bash script which then runs and assembles itself. this is genius.
  - gcr 10y ago
    It's using the shell's own tokenizer to parse asm! That's glorious! I don't really understand why the code works since I can't read x86 asm yet, but I think how it works is reasonably clear. Each instruction has its own bash function that writes its opcodes to the output file and the asm script to be assembled is (I think) sourced directly into the running shell session.
projectramo 10y ago
The next step is to write a new Bash in that C, and write a C compiled inside that Bash and so on. (See Godel, Escher, Bach)
- unsignedqword 10y ago
  Godel, Escher, Bash?
  - teddyh 10y ago
    https://en.wikipedia.org/wiki/G%C3%B6del,_Escher,_Bach https://en.wikipedia.org/wiki/G%C3%B6del,_Escher,_Bach
    - turbohedgehog 10y ago
      Sadly, you missed the pun
FatalBaboon 10y ago
Could he not remove the temp files and use process substitution instead? (looks cleaner in my opinion) i.e: cc -fPIC -o $sofile -shared <(cat <<'EOF' ... EOF )
- tehrei 10y ago
  That's some nice useless use of cat you have there ;) . You can just do cc -fPIC -o $sofile -shared -x c - <<'EOF' ... EOF
radiospiel 10y ago
I once built a package to allow redistribution of C/Flex/Go-scripts with just-in-time compilation (https://github.com/radiospiel/jit https://github.com/radiospiel/jit) but mine does not allow to mix the to-be-compiled language into the bash script itself; so count me impressed :)
gumby 10y ago
I used to write CGI in shell scripts. OK, it was the mid 1990s.
deleted 10y ago
[deleted]

106 points by eklitzke 10y ago

while read line; do echo $line>>$cfile done Okay, I know this is a joke and all, but that's the exact wrong way to do it. What you want to do is just cat > $cfile

ob 10y ago

> Has you ever wanted to combine the speed and safety of Bash with the raw, unbridled power of C? Uh, no? :)

susanthesquark 10y ago

this is cool do more

unsignedqword 10y ago

The insane things people do in Bash sometimes...although I don't think anything can top the x86 Assembler that was written entirely in Bash: http://lists.gnu.org/archive/html/bug-bash/2001-02/msg00054.html http://lists.gnu.org/archive/html/bug-bash/2001-02/msg00054....

ravenstine 10y ago
Neat!
skynetv2 10y ago
why ....
- mikestew 10y ago
  Click the link, and you're just a few spacebar presses away from answering that question for yourself (it's a few paragraphs down).
  - kevincox 10y ago
    > It just continuously cracks me up. My favourite of the listed reasons.
foxhill 10y ago
to call this an assembler is to not give it credit where it's due - this is not an assembler, it's much more than that. it's a set of functions for bash that when sourced make the assembly a valid bash script which then runs and assembles itself. this is genius.
- gcr 10y ago
  It's using the shell's own tokenizer to parse asm! That's glorious! I don't really understand why the code works since I can't read x86 asm yet, but I think how it works is reasonably clear. Each instruction has its own bash function that writes its opcodes to the output file and the asm script to be assembled is (I think) sourced directly into the running shell session.

projectramo 10y ago

The next step is to write a new Bash in that C, and write a C compiled inside that Bash and so on. (See Godel, Escher, Bach)

unsignedqword 10y ago
Godel, Escher, Bash?
- teddyh 10y ago
  https://en.wikipedia.org/wiki/G%C3%B6del,_Escher,_Bach https://en.wikipedia.org/wiki/G%C3%B6del,_Escher,_Bach
  - turbohedgehog 10y ago
    Sadly, you missed the pun

FatalBaboon 10y ago

Could he not remove the temp files and use process substitution instead? (looks cleaner in my opinion) i.e: cc -fPIC -o $sofile -shared <(cat <<'EOF' ... EOF )

tehrei 10y ago
That's some nice useless use of cat you have there ;) . You can just do cc -fPIC -o $sofile -shared -x c - <<'EOF' ... EOF

radiospiel 10y ago

I once built a package to allow redistribution of C/Flex/Go-scripts with just-in-time compilation (https://github.com/radiospiel/jit https://github.com/radiospiel/jit) but mine does not allow to mix the to-be-compiled language into the bash script itself; so count me impressed :)

gumby 10y ago

I used to write CGI in shell scripts. OK, it was the mid 1990s.

deleted 10y ago

[deleted]