hello,
to avoid having to read twice the entire large file, I use the tee tool in
this way to calculate two checksums "simultaneously" :
file_info(){
echo -n ${1:=/dev/stdin}$'\t'
(
tee < "${1}" \
>( md5sum >&3 ) \
>( sha1sum >&3 ) \
>/dev/null
) 3>&1 |
tr '\n' '\t'
echo
}
it works perfectly because both tools used, md5sum and sha1sum, consume all
the data.
on the other hand, the function returns wrong fingerprints if I insert a
tool like file :
file_info(){
echo -n ${1:=/dev/stdin}$'\t'
(
tee < "${1}" \
>( file --mime-type -b -e compress -e tar -e elf - >&3 ) \
>( md5sum >&3 ) \
>( sha1sum >&3 ) \
>/dev/null
) 3>&1 |
tr '\n' '\t'
echo
}
it no longer works because the data flow is quickly interrupted by tee
which does not consume all the data.
do you know a way to get the file type in parallel with the fingerprint ?
getting its type is just an example : the idea is to open the file only
once...
regards, lacsaP.
