env_parset variablename [options for GNU Parallel]
env_parset is a shell function that puts the output from env_parallel into shell variables.
The parset and env_parset functions are defined as part of env_parallel.
If variablename is a single variable name, this will be treated as the destination variable and made into an array.
If variablename contains multiple names separated by ',' or space, the names will be the destination variables. The number of names must be at least the number of jobs - otherwise some tmp files will not be cleaned up.
Put output into myarray:
parset myarray seq 3 ::: 4 5 6
echo "${myarray[1]}"
Put output into vars $seq, $pwd, $ls:
parset "seq pwd ls" ::: "seq 10" pwd ls echo "$ls"
Put output into vars $seq, $pwd, $ls:
into_vars=(seq pwd ls)
parset "${into_vars[*]}" ::: "seq 10" pwd ls
echo "$ls"
The commands to run can be an array:
cmd=("echo first" "echo '<<joe \"double space\" cartoon>>'" "pwd")
parset data ::: "${cmd[@]}"
echo "${data[1]}"
echo "${data[2]}"
parset can read from stdin (standard input) if it is a file:
parset res echo < parallel_input_file
but parset can not be part of a pipe. In particular this means it cannot read from a pipe or write to a pipe:
seq 10 | parset res echo Does not work
but must instead use a tempfile:
seq 10 > parallel_input
parset res echo :::: parallel_input
echo "${res[1]}"
echo "${res[9]}"
or a FIFO:
mkfifo input_fifo
seq 30 > input_fifo &
parset res echo :::: input_fifo
echo "${res[1]}"
echo "${res[29]}"
or Bash/Zsh/Ksh process substitution:
parset res echo :::: <(seq 100)
echo "${res[1]}"
echo "${res[99]}"
Installation
Put this in the relevant $HOME/.bashrc or $HOME/.zshenv or $HOME/.kshrc:
. `which env_parallel.bash` . `which env_parallel.zsh` source `which env_parallel.ksh`
E.g. by doing:
echo '. `which env_parallel.bash`' >> $HOME/.bashrc echo '. `which env_parallel.zsh`' >> $HOME/.zshenv echo 'source `which env_parallel.ksh`' >> $HOME/.kshrc
or by doing:
env_parallel --install
ash does not support arrays.
Put output into vars $seq, $pwd, $ls:
parset "seq pwd ls" ::: "seq 10" pwd ls echo "$ls"
parset can read from stdin (standard input) if it is a file:
parset res1,res2,res3 echo < parallel_input_file
but parset can not be part of a pipe. In particular this means it cannot read from a pipe or write to a pipe:
seq 3 | parset res1,res2,res3 echo Does not work
but must instead use a tempfile:
seq 3 > parallel_input parset res1,res2,res3 echo :::: parallel_input echo "$res1" echo "$res2" echo "$res3"
or a FIFO:
mkfifo input_fifo seq 3 > input_fifo & parset res1,res2,res3 echo :::: input_fifo echo "$res1" echo "$res2" echo "$res3"
Installation
Put the relevant one of these into $HOME/.profile:
. `which env_parallel.sh` . `which env_parallel.ash` . `which env_parallel.dash`
E.g. by doing:
echo '. `which env_parallel.ash`' >> $HOME/.bashrc
or by doing:
env_parallel --install
O. Tange (2011): GNU Parallel - The Command-Line Power Tool, ;login: The USENIX Magazine, February 2011:42-47.
This helps funding further development; and it won't cost you a cent. If you pay 10000 EUR you should feel free to use GNU Parallel without citing.
Copyright (C) 2007-10-18 Ole Tange, http://ole.tange.dk
Copyright (C) 2008-2010 Ole Tange, http://ole.tange.dk
Copyright (C) 2010-2020 Ole Tange, http://ole.tange.dk and Free Software Foundation, Inc.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>.
Under the following conditions:
With the understanding that:
A copy of the full license is included in the file as cc-by-sa.txt.