Ao tentar executar, no zsh, o seguinte comando retirado deaqui
/lib64/ld-linux-x86-64.so.2 =(/bin/echo -e '#include <stdio.h>\nint main(){printf("c one liners\\n");}'\
| sudo gcc -x c -o /dev/stdout -)
Ele retorna o seguinte erro
/tmp/zshgYCSAH: erro ao carregar bibliotecas compartilhadas: /tmp/zshgYCSAH: arquivo muito curto
No entanto, emitir
/lib64/ld-linux-x86-64.so.2 /bin/echo -e '#include <stdio.h>\nint main(){printf("c one liners\\n");}'
#include <stdio.h>
int main(){printf("c one liners\n");}
retorna o comportamento esperado.
Estou faltando algo realmente óbvio aqui?
Permissões e versão do SO e GCC
uname -a
Linux debian 4.19.0-8-amd64 #1 SMP Debian 4.19.98-1 (2020-01-26) x86_64 GNU/Linux
\ls -l /usr/bin/x86_64-linux-gnu-gcc-8
-rwxr-x--- 1 root root 1100664 Apr 6 2019 /usr/bin/x86_64-linux-gnu-gcc-8
sudo gcc --version
gcc (Debian 8.3.0-6) 8.3.0
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Contexto
file =(/bin/echo -e '#include <stdio.h>\nint main(){printf("c one liners\\n");}' | sudo gcc -x c -o /dev/stdout -)
/tmp/zshrOdFnK: ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 3.2.0, BuildID[sha1]=d94f408ab2b445d20624e2b1fb7c4939dfc25c46, not stripped
\ls -l =(/bin/echo -e '#include <stdio.h>\nint main(){printf("c one liners\\n");}' | sudo gcc -x c -o /dev/stdout -)
-rw------- 1 paulo paulo 16600 Mar 30 12:37 /tmp/zshTNxAXl
O subcomando do compilador parece estar funcionando corretamente
/bin/echo -e '#include <stdio.h>\nint main(){printf("c one liners\\n");}' | gcc -x c -o a.out -
ls -l a.out
-rwxr-xr-x 1 root root 16600 Mar 30 12:03 a.out
du a.out
20 a.out
./a.out
c one liners
Responder1
Valeria a pena verificar se o subcomando do compilador está funcionando corretamente
/bin/echo -e '#include <stdio.h>\nint main(){printf("c one liners\\n");}' | gcc -x c -o a.out -
ls -l a.out
Se o resultado for que o arquivo de saída temporário tiver comprimento zero, isso acionará o erro que você está vendo
/lib64/ld-linux-x86-64.so.2 /dev/null
/dev/null: error while loading shared libraries: /dev/null: file too short
Responder2
Acabei de descobrir qual é a origem do problema: permissões.
Permissões do GCC
\ls -l /usr/bin/gcc
lrwxrwxrwx 1 root root 5 Feb 25 2019 /usr/bin/gcc -> gcc-8
\ls -l /usr/bin/gcc-8
lrwxrwxrwx 1 root root 22 Apr 6 2019 /usr/bin/gcc-8 -> x86_64-linux-gnu-gcc-8
\ls -l /usr/bin/x86_64-linux-gnu-gcc-8
-rwxr-x--- 1 root root 1100664 Apr 6 2019 /usr/bin/x86_64-linux-gnu-gcc-8
Permissões do objeto ELF
\ls -l =(/bin/echo -e '#include <stdio.h>\nint main(){printf("c one liners\\n");}' | sudo gcc -x c -o /dev/stdout -)
-rw------- 1 paulo paulo 16600 Mar 30 12:37 /tmp/zshTNxAXl
Emitindo o comando prefixado comsudo
sudo /lib64/ld-linux-x86-64.so.2 =(/bin/echo -e '#include <stdio.h>\nint main(){printf("c one liners\\n");}' | sudo gcc -x c -o /dev/stdout -)
c one liners
retorna o resultado correto.