eklitzke / c.sh
- воскресенье, 19 июня 2016 г. в 03:12:22
Shell
Inline C/asm in Bash
Has you ever wanted to combine the speed and safety of Bash with the raw, unbridled power of C? Thanks to @taviso's wonderful ctypes.sh this is possible:
#!/bin/bash
# where ctypes.sh is installed; you will likely have to change this
LD_LIBRARY_PATH=$HOME/local/lib
. ~/code/ctypes.sh/ctypes.sh
# compile stdin to a DSO
function build {
cfile=$(mktemp /tmp/XXXXXX.c)
sofile=$(mktemp /tmp/XXXXXX.so)
while read line; do
echo $line>>$cfile
done
cc -fPIC -shared $cfile -o $sofile
rm -f $cfile
echo $sofile
}
# our code
sofile=$(build <<EOF
#include <stdio.h>
void hello_world(void) {
puts("hello world");
}
int popcnt(int num) {
int out;
__asm__("popcnt %1, %0"
:"=r"(out)
:"r"(num)
:"0"
);
return out;
}
EOF
)
# clean up when we're done
trap "rm -f $sofile" EXIT
# load the code
dlopen $sofile
# print hello world
dlcall hello_world
# get the popcnt of 5
dlcall -r int -n out popcnt 5
echo $out | egrep -o '[0-9]+'
More details on my blog.