src/env_parallel.ksh

   1 #!/usr/bin/env ksh
   2
   3 # This file must be sourced in sh/ash/dash/bash/ksh/mksh/zsh:
   4 #
   5 #   . env_parallel.sh
   6 #   source env_parallel.ash
   7 #   source env_parallel.dash
   8 #   source env_parallel.bash
   9 #   source env_parallel.ksh
  10 #   source env_parallel.mksh
  11 #   source env_parallel.zsh
  12 #
  13 # after which 'env_parallel' works
  14 #
  15 #
  16 # Copyright (C) 2016-2024 Ole Tange, http://ole.tange.dk and Free
  17 # Software Foundation, Inc.
  18 #
  19 # This program is free software; you can redistribute it and/or modify
  20 # it under the terms of the GNU General Public License as published by
  21 # the Free Software Foundation; either version 3 of the License, or
  22 # (at your option) any later version.
  23 #
  24 # This program is distributed in the hope that it will be useful, but
  25 # WITHOUT ANY WARRANTY; without even the implied warranty of
  26 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  27 # General Public License for more details.
  28 #
  29 # You should have received a copy of the GNU General Public License
  30 # along with this program; if not, see <http://www.gnu.org/licenses/>
  31 # or write to the Free Software Foundation, Inc., 51 Franklin St,
  32 # Fifth Floor, Boston, MA 02110-1301 USA
  33 #
  34 # SPDX-FileCopyrightText: 2021-2024 Ole Tange, http://ole.tange.dk and Free Software and Foundation, Inc.
  35 # SPDX-License-Identifier: GPL-3.0-or-later
  36 # shellcheck disable=SC2006
  37
  38 env_parallel() {
  39     # env_parallel.{sh,ash,dash,bash,ksh,mksh,zsh}
  40
  41     # Check shell dialect
  42     if [ -n "$BASH_VERSION" ]; then
  43         _shell_DIALECT=bash
  44         _eval_needed=false
  45         _prefix_PARALLEL_ENV=_prefix_PARALLEL_ENV_bash
  46     elif [ -n "$ZSH_VERSION" ]; then
  47         _shell_DIALECT=zsh
  48         _eval_needed=true
  49         _prefix_PARALLEL_ENV=false
  50     elif [ -n "$KSH_VERSION" ]; then
  51         _shell_DIALECT=ksh
  52         _eval_needed=false
  53         _prefix_PARALLEL_ENV=false
  54     else
  55         # Dash/ash - can these be detected better?
  56         _shell_DIALECT="sh"
  57         _eval_needed=false
  58         _prefix_PARALLEL_ENV=false
  59     fi
  60     _names_of_ALIASES() {
  61         _names_of_ALIASES_$_shell_DIALECT
  62     }
  63     _names_of_ALIASES_sh() {
  64         # alias fails on Unixware 5
  65         for _i in `alias 2>/dev/null | perl -ne 's/^alias //;s/^(\S+)=.*/$1/ && print' 2>/dev/null`; do
  66             # Check if this name really is an alias
  67             # or just part of a multiline alias definition
  68             if alias "$_i" >/dev/null 2>/dev/null; then
  69                 echo "$_i"
  70             fi
  71         done
  72     }
  73     _names_of_ALIASES_bash() {
  74         # No aliases will return false. This error should be ignored.
  75         # shellcheck disable=SC3044
  76         compgen -a || true
  77     }
  78     _names_of_ALIASES_ksh() {
  79         alias | perl -pe 's/=.*//'
  80     }
  81     _names_of_ALIASES_zsh() {
  82         # shellcheck disable=SC2086,SC2296
  83         print -l ${(k)aliases}
  84     }
  85     _bodies_of_ALIASES() {
  86         _bodies_of_ALIASES_$_shell_DIALECT "$@"
  87     }
  88     _bodies_of_ALIASES_sh() {
  89         # alias may return:
  90         #   myalias='definition' (GNU/Linux ash)
  91         #   alias myalias='definition' (FreeBSD ash)
  92         # so remove 'alias ' from first line
  93         for _i in "$@"; do
  94                 echo 'alias '"`alias "$_i" | perl -pe '1..1 and s/^alias //'`"
  95         done
  96     }
  97     _bodies_of_ALIASES_bash() {
  98         # shellcheck disable=SC3043
  99         local _i
 100         for _i in "$@"; do
 101             # shellcheck disable=SC2046
 102             if [ $(alias "$_i" | wc -l) = 1 ] ; then
 103                 true Alias is a single line. Good.
 104             else
 105                 _warning_PAR "Alias '$_i' contains newline."
 106                 _warning_PAR "Make sure the command has at least one newline after '$_i'."
 107                 _warning_PAR "See BUGS in 'man env_parallel'."
 108             fi
 109         done
 110         alias "$@"
 111     }
 112     _bodies_of_ALIASES_ksh() {
 113         alias "$@" | perl -pe 's/^/alias /;
 114                      sub warning { print STDERR "env_parallel: Warning: @_\n"; }
 115                      if(/^alias (\S+)=\$.*\\n/) {
 116                          warning("Alias \"$1\" contains newline.");
 117                          warning("Make sure the command has at least one newline after \"$1\".");
 118                          warning("See BUGS in \"man env_parallel\".");
 119                      }'
 120
 121     }
 122     _bodies_of_ALIASES_zsh() {
 123         # shellcheck disable=SC3043
 124         local _i
 125         for _i in "$@"; do
 126                 echo 'alias '"$(alias "$_i")"
 127         done
 128     }
 129     _names_of_FUNCTIONS() {
 130         _names_of_FUNCTIONS_$_shell_DIALECT
 131     }
 132     _names_of_FUNCTIONS_bash() {
 133         # shellcheck disable=SC3044
 134         compgen -A function
 135     }
 136     _names_of_maybe_FUNCTIONS() {
 137         set | perl -ne '/^([A-Z_0-9]+)\s*\(\)\s*\{?$/i and print "$1\n"'
 138     }
 139     _names_of_FUNCTIONS_sh() {
 140         # myfunc is a function
 141         # shellcheck disable=SC2046
 142         LANG=C type `_names_of_maybe_FUNCTIONS` |
 143             perl -ne '/^(\S+) is a function$/ and not $seen{$1}++ and print "$1\n"'
 144     }
 145     _names_of_FUNCTIONS_ksh() {
 146         # shellcheck disable=SC3044
 147         typeset +f | perl -pe 's/\(\).*//; s/ .*//;'
 148     }
 149     _names_of_FUNCTIONS_zsh() {
 150         # shellcheck disable=SC2086,SC2296
 151         print -l ${(k)functions}
 152     }
 153     _bodies_of_FUNCTIONS() {
 154         _bodies_of_FUNCTIONS_$_shell_DIALECT "$@"
 155     }
 156     _bodies_of_FUNCTIONS_sh() {
 157         LANG=C type "$@" | perl -ne '/^(\S+) is a function$/ or print'
 158     }
 159     _bodies_of_FUNCTIONS_bash() {
 160         # shellcheck disable=SC3044
 161         typeset -f "$@"
 162     }
 163     _bodies_of_FUNCTIONS_ksh() {
 164         functions "$@"
 165     }
 166     _bodies_of_FUNCTIONS_zsh() {
 167         # shellcheck disable=SC3044
 168         typeset -f "$@"
 169     }
 170     _names_of_VARIABLES() {
 171         _names_of_VARIABLES_$_shell_DIALECT
 172     }
 173     _names_of_VARIABLES_sh() {
 174         # This may screw up if variables contain \n and =
 175         set | perl -ne 's/^(\S+?)=.*/$1/ and print;'
 176     }
 177     _names_of_VARIABLES_bash() {
 178         # shellcheck disable=SC3044
 179         compgen -A variable
 180     }
 181     _names_of_VARIABLES_ksh() {
 182         # shellcheck disable=SC3044
 183         typeset +p |
 184             perl -pe 's/^(type)?set( [-+][a-zA-Z0-9]*)* //; s/(\[\d+\])?=.*//' |
 185             uniq
 186     }
 187     _names_of_VARIABLES_zsh() {
 188         # shellcheck disable=SC2086,SC2296
 189         print -l ${(k)parameters}
 190     }
 191     _bodies_of_VARIABLES() {
 192         _bodies_of_VARIABLES_$_shell_DIALECT "$@"
 193     }
 194     _bodies_of_VARIABLES_sh() {
 195         # Crappy typeset -p
 196         for _i in "$@"
 197         do
 198             perl -e 'print @ARGV' "$_i="
 199             eval echo "\"\$$_i\"" | perl -e '$/=undef; $a=<>; chop($a); print $a' |
 200                 perl -pe 's/[\002-\011\013-\032\\\#\?\`\(\)\{\}\[\]\^\*\<\=\>\~\|\; \"\!\$\&\202-\377]/\\$&/go;'"s/'/\\\'/g; s/[\n]/'\\n'/go;";
 201             echo
 202         done
 203     }
 204     _bodies_of_VARIABLES_bash() {
 205         # shellcheck disable=SC3044
 206         typeset -p "$@"
 207     }
 208     _bodies_of_VARIABLES_ksh() {
 209         # shellcheck disable=SC3044
 210         typeset -p "$@"
 211     }
 212     _bodies_of_VARIABLES_zsh() {
 213         # shellcheck disable=SC3044
 214         typeset -p "$@"
 215     }
 216     _ignore_HARDCODED() {
 217         _ignore_HARDCODED_$_shell_DIALECT
 218     }
 219     _ignore_HARDCODED_sh() {
 220         # These names cannot be detected
 221         echo '(_|TIMEOUT|IFS)'
 222     }
 223     _ignore_HARDCODED_bash() {
 224         # Copying $RANDOM will cause it not to be random
 225         # The rest cannot be detected as read-only
 226         echo '(RANDOM|_|TIMEOUT|GROUPS|FUNCNAME|DIRSTACK|PIPESTATUS|USERNAME|BASHPID|BASH_[A-Z_]+)'
 227     }
 228     _ignore_HARDCODED_ksh() {
 229         # These names cannot be detected
 230         echo '(_|TIMEOUT|IFS)'
 231     }
 232     _ignore_HARDCODED_zsh() {
 233         # These names cannot be detected
 234         echo '([-\?\#\!\$\*\@\_0]|zsh_eval_context|ZSH_EVAL_CONTEXT|LINENO|IFS|commands|functions|options|aliases|EUID|EGID|UID|GID|dis_patchars|patchars|terminfo|galiases|keymaps|parameters|jobdirs|dirstack|functrace|funcsourcetrace|zsh_scheduled_events|dis_aliases|dis_reswords|dis_saliases|modules|reswords|saliases|widgets|userdirs|historywords|nameddirs|termcap|dis_builtins|dis_functions|jobtexts|funcfiletrace|dis_galiases|builtins|history|jobstates|funcstack|run-help)'
 235     }
 236     _ignore_READONLY() {
 237         _ignore_READONLY_$_shell_DIALECT
 238     }
 239     _parse_READONLY() {
 240         # shellcheck disable=SC1078,SC1079,SC2026
 241         perl -e '@r = map {
 242                 chomp;
 243                 # sh on UnixWare: readonly TIMEOUT
 244                 # ash: readonly var='val'
 245                 # ksh: var='val'
 246                 # mksh: PIPESTATUS[0]
 247                 s/^(readonly )?([^=\[ ]*?)(\[\d+\])?(=.*|)$/$2/ or
 248                 # bash: declare -ar BASH_VERSINFO=([0]="4" [1]="4")
 249                 # zsh: typeset -r var='val'
 250                   s/^\S+\s+\S+\s+(\S[^=]*)(=.*|$)/$1/;
 251                 $_ } <>;
 252             $vars = join "|",map { quotemeta $_ } @r;
 253             print $vars ? "($vars)" : "(,,nO,,VaRs,,)";
 254             '
 255     }
 256     _ignore_READONLY_sh() {
 257         readonly | _parse_READONLY
 258     }
 259     _ignore_READONLY_bash() {
 260         readonly | _parse_READONLY
 261     }
 262     _ignore_READONLY_ksh() {
 263         readonly | _parse_READONLY
 264     }
 265     _ignore_READONLY_zsh() {
 266         # shellcheck disable=SC3044
 267         typeset -pr | _parse_READONLY
 268     }
 269     _remove_bad_NAMES() {
 270         # Do not transfer vars and funcs from env_parallel
 271         # shellcheck disable=SC2006
 272         _ignore_RO="`_ignore_READONLY`"
 273         # shellcheck disable=SC2006
 274         _ignore_HARD="`_ignore_HARDCODED`"
 275         # To avoid depending on grep dialect, use Perl version of:
 276         # grep -Ev '^(...)$' |
 277         perl -ne '/^(
 278                      PARALLEL_ENV|
 279                      PARALLEL_TMP|
 280                      _alias_NAMES|
 281                      _bodies_of_ALIASES|
 282                      _bodies_of_FUNCTIONS|
 283                      _bodies_of_VARIABLES|
 284                      _error_PAR|
 285                      _function_NAMES|
 286                      _get_ignored_VARS|
 287                      _grep_REGEXP|
 288                      _ignore_HARD|
 289                      _ignore_HARDCODED|
 290                      _ignore_READONLY|
 291                      _ignore_RO|
 292                      _ignore_UNDERSCORE|
 293                      _list_alias_BODIES|
 294                      _list_function_BODIES|
 295                      _list_variable_VALUES|
 296                      _make_grep_REGEXP|
 297                      _names_of_ALIASES|
 298                      _names_of_FUNCTIONS|
 299                      _names_of_VARIABLES|
 300                      _names_of_maybe_FUNCTIONS|
 301                      _parallel_exit_CODE|
 302                      _prefix_PARALLEL_ENV|
 303                      _prefix_PARALLEL_ENV_bash|
 304                      _remove_bad_NAMES|
 305                      _remove_readonly|
 306                      _variable_NAMES|
 307                      _warning_PAR|
 308                      _which_PAR)$/x and next;
 309             # Filter names matching --env
 310             /^'"$_grep_REGEXP"'$/ or next;
 311             /^'"$_ignore_UNDERSCORE"'$/ and next;
 312             # Remove readonly variables
 313             /^'"$_ignore_RO"'$/ and next;
 314             /^'"$_ignore_HARD"'$/ and next;
 315             print;'
 316     }
 317     _prefix_PARALLEL_ENV_bash() {
 318         # shellcheck disable=SC3044
 319         shopt 2>/dev/null |
 320         perl -pe 's:\s+off:;: and s/^/shopt -u /;
 321                   s:\s+on:;: and s/^/shopt -s /;
 322                   s:;$:&>/dev/null;:';
 323         echo 'shopt -s expand_aliases &>/dev/null';
 324     }
 325
 326     _get_ignored_VARS() {
 327         perl -e '
 328             for(@ARGV){
 329                 $next_is_env and push @envvar, split/,/, $_;
 330                 $next_is_env=/^--env$/;
 331             }
 332             if(grep { /^_$/ } @envvar) {
 333                 if(not open(IN, "<", "$ENV{HOME}/.parallel/ignored_vars")) {
 334                     print STDERR "parallel: Error: ",
 335                     "Run \"parallel --record-env\" in a clean environment first.\n";
 336                 } else {
 337                     chomp(@ignored_vars = <IN>);
 338                 }
 339             }
 340             if($ENV{PARALLEL_IGNORED_NAMES}) {
 341                 push @ignored_vars, split/\s+/, $ENV{PARALLEL_IGNORED_NAMES};
 342                 chomp @ignored_vars;
 343             }
 344             $vars = join "|",map { quotemeta $_ } @ignored_vars;
 345             print $vars ? "($vars)" : "(,,nO,,VaRs,,)";
 346             ' -- "$@"
 347     }
 348
 349     # Get the --env variables if set
 350     # --env _ should be ignored
 351     # and convert  a b c  to (a|b|c)
 352     # If --env not set: Match everything (.*)
 353     _make_grep_REGEXP() {
 354         perl -e '
 355             for(@ARGV){
 356                 /^_$/ and $next_is_env = 0;
 357                 $next_is_env and push @envvar, split/,/, $_;
 358                 $next_is_env = /^--env$/;
 359             }
 360             $vars = join "|",map { quotemeta $_ } @envvar;
 361             print $vars ? "($vars)" : "(.*)";
 362             ' -- "$@"
 363     }
 364     _which_PAR() {
 365         # type returns:
 366         #   ll is an alias for ls -l (in ash)
 367         #   bash is a tracked alias for /bin/bash
 368         #   true is a shell builtin (in bash)
 369         #   myfunc is a function (in bash)
 370         #   myfunc is a shell function (in zsh)
 371         #   which is /usr/bin/which (in sh, bash)
 372         #   which is hashed (/usr/bin/which)
 373         #   gi is aliased to `grep -i' (in bash)
 374         #   aliased to `alias | /usr/bin/which --tty-only --read-alias --show-dot --show-tilde'
 375         # Return 0 if found, 1 otherwise
 376         LANG=C type "$@" |
 377             perl -pe '$exit += (s/ is an alias for .*// ||
 378                                 s/ is aliased to .*// ||
 379                                 s/ is a function// ||
 380                                 s/ is a shell function// ||
 381                                 s/ is a shell builtin// ||
 382                                 s/.* is hashed .(\S+).$/$1/ ||
 383                                 s/.* is (a tracked alias for )?//);
 384                       END { exit not $exit }'
 385     }
 386     _warning_PAR() {
 387         echo "env_parallel: Warning: $*" >&2
 388     }
 389     _error_PAR() {
 390         echo "env_parallel: Error: $*" >&2
 391     }
 392
 393     if _which_PAR parallel >/dev/null; then
 394         true parallel found in path
 395     else
 396         # shellcheck disable=SC2016
 397         _error_PAR 'parallel must be in $PATH.'
 398         return 255
 399     fi
 400
 401     # Grep regexp for vars given by --env
 402     # shellcheck disable=SC2006
 403     _grep_REGEXP="`_make_grep_REGEXP \"$@\"`"
 404     unset _make_grep_REGEXP
 405
 406     # Deal with --env _
 407     # shellcheck disable=SC2006
 408     _ignore_UNDERSCORE="`_get_ignored_VARS \"$@\"`"
 409     unset _get_ignored_VARS
 410
 411     # --record-env
 412     if perl -e 'exit grep { /^--record-env$/ } @ARGV' -- "$@"; then
 413         true skip
 414     else
 415         (_names_of_ALIASES;
 416          _names_of_FUNCTIONS;
 417          _names_of_VARIABLES) |
 418             cat > "$HOME"/.parallel/ignored_vars
 419         return 0
 420     fi
 421
 422     # --session
 423     if perl -e 'exit grep { /^--session$/ } @ARGV' -- "$@"; then
 424         true skip
 425     else
 426         # Insert ::: between each level of session
 427         # so you can pop off the last ::: at --end-session
 428         # shellcheck disable=SC2006
 429         PARALLEL_IGNORED_NAMES="`echo \"$PARALLEL_IGNORED_NAMES\";
 430           echo :::;
 431           (_names_of_ALIASES;
 432            _names_of_FUNCTIONS;
 433            _names_of_VARIABLES) | perl -ne '
 434             BEGIN{
 435               map { $ignored_vars{$_}++ }
 436                 split/\s+/, $ENV{PARALLEL_IGNORED_NAMES};
 437             }
 438             chomp;
 439             for(split/\s+/) {
 440               if(not $ignored_vars{$_}) {
 441                 print $_,\"\\n\";
 442               }
 443             }
 444             '`"
 445         export PARALLEL_IGNORED_NAMES
 446         return 0
 447     fi
 448     if perl -e 'exit grep { /^--end.?session$/ } @ARGV' -- "$@"; then
 449         true skip
 450     else
 451         # Pop off last ::: from PARALLEL_IGNORED_NAMES
 452         # shellcheck disable=SC2006
 453         PARALLEL_IGNORED_NAMES="`perl -e '
 454           $ENV{PARALLEL_IGNORED_NAMES} =~ s/(.*):::.*?$/$1/s;
 455           print $ENV{PARALLEL_IGNORED_NAMES}
 456         '`"
 457         return 0
 458     fi
 459     # Grep alias names
 460     # shellcheck disable=SC2006
 461     _alias_NAMES="`_names_of_ALIASES | _remove_bad_NAMES | xargs echo`"
 462     _list_alias_BODIES="_bodies_of_ALIASES $_alias_NAMES"
 463     if [ "$_alias_NAMES" = "" ] ; then
 464         # no aliases selected
 465         _list_alias_BODIES="true"
 466     fi
 467     unset _alias_NAMES
 468
 469     # Grep function names
 470     # shellcheck disable=SC2006
 471     _function_NAMES="`_names_of_FUNCTIONS | _remove_bad_NAMES | xargs echo`"
 472     _list_function_BODIES="_bodies_of_FUNCTIONS $_function_NAMES"
 473     if [ "$_function_NAMES" = "" ] ; then
 474         # no functions selected
 475         _list_function_BODIES="true"
 476     fi
 477     unset _function_NAMES
 478
 479     # Grep variable names
 480     # shellcheck disable=SC2006
 481     _variable_NAMES="`_names_of_VARIABLES | _remove_bad_NAMES | xargs echo`"
 482     _list_variable_VALUES="_bodies_of_VARIABLES $_variable_NAMES"
 483     if [ "$_variable_NAMES" = "" ] ; then
 484         # no variables selected
 485         _list_variable_VALUES="true"
 486     fi
 487     unset _variable_NAMES
 488
 489     if $_eval_needed ; then
 490         # shellcheck disable=SC2006
 491         PARALLEL_ENV="`
 492         eval $_prefix_PARALLEL_ENV;
 493         eval $_list_alias_BODIES;
 494         eval $_list_function_BODIES;
 495         eval $_list_variable_VALUES;
 496         `"
 497     else
 498         # shellcheck disable=SC2006
 499         PARALLEL_ENV="`
 500         $_prefix_PARALLEL_ENV;
 501         $_list_alias_BODIES;
 502         $_list_function_BODIES;
 503         $_list_variable_VALUES;
 504         `"
 505     fi
 506     export PARALLEL_ENV
 507     # Free up some env space
 508     unset _list_alias_BODIES _list_variable_VALUES _list_function_BODIES
 509     unset _bodies_of_ALIASES _bodies_of_VARIABLES _bodies_of_FUNCTIONS
 510     unset _names_of_ALIASES _names_of_VARIABLES _names_of_FUNCTIONS
 511     unset _ignore_HARDCODED _ignore_READONLY _ignore_UNDERSCORE
 512     unset _remove_bad_NAMES _grep_REGEXP _parse_READONLY
 513     unset _prefix_PARALLEL_ENV
 514     unset _ignore_READONLY_sh _ignore_READONLY_bash
 515     unset _ignore_READONLY_ksh _ignore_READONLY_zsh
 516     unset _ignore_HARDCODED_sh _ignore_HARDCODED_bash
 517     unset _ignore_HARDCODED_ksh _ignore_HARDCODED_zsh
 518     unset _bodies_of_ALIASES_ksh _bodies_of_ALIASES_sh
 519     unset _bodies_of_ALIASES_zsh _bodies_of_FUNCTIONS_bash
 520     unset _bodies_of_FUNCTIONS_ksh _bodies_of_FUNCTIONS_sh
 521     unset _bodies_of_FUNCTIONS_zsh _bodies_of_VARIABLES_bash
 522     unset _bodies_of_VARIABLES_ksh _bodies_of_VARIABLES_sh
 523     unset _bodies_of_VARIABLES_zsh
 524     unset _names_of_ALIASES _names_of_ALIASES_bash
 525     unset _names_of_ALIASES_ksh _names_of_ALIASES_sh
 526     unset _names_of_ALIASES_zsh _names_of_FUNCTIONS
 527     unset _names_of_FUNCTIONS_bash _names_of_FUNCTIONS_ksh
 528     unset _names_of_FUNCTIONS_sh _names_of_FUNCTIONS_zsh
 529     unset _names_of_VARIABLES _names_of_VARIABLES_bash
 530     unset _names_of_VARIABLES_ksh _names_of_VARIABLES_sh
 531     unset _names_of_VARIABLES_zsh _names_of_maybe_FUNCTIONS
 532
 533     # Test if environment is too big by running 'true'
 534     # shellcheck disable=SC2006,SC2092
 535     if `_which_PAR true` >/dev/null 2>/dev/null ; then
 536         parallel "$@"
 537         _parallel_exit_CODE=$?
 538         # Clean up variables/functions
 539         unset PARALLEL_ENV
 540         unset _which_PAR _which_TRUE
 541         unset _warning_PAR _error_PAR
 542         # Unset _parallel_exit_CODE before return
 543         eval "unset _parallel_exit_CODE; return $_parallel_exit_CODE"
 544     else
 545         unset PARALLEL_ENV;
 546         _error_PAR "Your environment is too big."
 547         _error_PAR "You can try 3 different approaches:"
 548         _error_PAR "1. Run 'env_parallel --session' before you set"
 549         _error_PAR "   variables or define functions."
 550         _error_PAR "2. Use --env and only mention the names to copy."
 551         _error_PAR "3. Try running this in a clean environment once:"
 552         _error_PAR "     env_parallel --record-env"
 553         _error_PAR "   And then use '--env _'"
 554         _error_PAR "For details see: man env_parallel"
 555         return 255
 556     fi
 557 }
 558
 559 parset() {
 560     _parset_PARALLEL_PRG=parallel
 561     _parset_main "$@"
 562 }
 563
 564 env_parset() {
 565     _parset_PARALLEL_PRG=env_parallel
 566     _parset_main "$@"
 567 }
 568
 569 _parset_main() {
 570     # If $1 contains ',' or space:
 571     #   Split on , to get the destination variable names
 572     # If $1 is a single destination variable name:
 573     #   Treat it as the name of an array
 574     #
 575     #   # Create array named myvar
 576     #   parset myvar echo ::: {1..10}
 577     #   echo ${myvar[5]}
 578     #
 579     #   # Put output into $var_a $var_b $var_c
 580     #   varnames=(var_a var_b var_c)
 581     #   parset "${varnames[*]}" echo ::: {1..3}
 582     #   echo $var_c
 583     #
 584     #   # Put output into $var_a4 $var_b4 $var_c4
 585     #   parset "var_a4 var_b4 var_c4" echo ::: {1..3}
 586     #   echo $var_c4
 587
 588     _parset_NAME="$1"
 589     if [ "$_parset_NAME" = "" ] ; then
 590         echo parset: Error: No destination variable given. >&2
 591         echo parset: Error: Try: >&2
 592         echo parset: Error: ' ' parset myarray echo ::: foo bar >&2
 593         return 255
 594     fi
 595     if [ "$_parset_NAME" = "--help" ] ; then
 596         echo parset: Error: Usage: >&2
 597         echo parset: Error: ' ' parset varname GNU Parallel options and command >&2
 598         echo
 599         parallel --help
 600         return 255
 601     fi
 602     if [ "$_parset_NAME" = "--version" ] ; then
 603         # shellcheck disable=SC2006
 604         echo "parset 20240522 (GNU parallel `parallel --minversion 1`)"
 605         echo "Copyright (C) 2007-2024 Ole Tange, http://ole.tange.dk and Free Software"
 606         echo "Foundation, Inc."
 607         echo "License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>"
 608         echo "This is free software: you are free to change and redistribute it."
 609         echo "GNU parallel comes with no warranty."
 610         echo
 611         echo "Web site: https://www.gnu.org/software/parallel"
 612         echo
 613         echo "When using programs that use GNU Parallel to process data for publication"
 614         echo "please cite as described in 'parallel --citation'."
 615         echo
 616         return 255
 617     fi
 618     shift
 619
 620     # Bash: declare -A myassoc=( )
 621     # Zsh: typeset -A myassoc=( )
 622     # Ksh: typeset -A myassoc=( )
 623     # shellcheck disable=SC2039,SC2169,SC3044
 624     if (typeset -p "$_parset_NAME" 2>/dev/null; echo) |
 625             perl -ne 'exit not (/^declare[^=]+-A|^typeset[^=]+-A/)' ; then
 626         # This is an associative array
 627         # shellcheck disable=SC2006
 628         eval "`$_parset_PARALLEL_PRG -k --_parset assoc,"$_parset_NAME" "$@"`"
 629         # The eval returns the function!
 630     else
 631         # This is a normal array or a list of variable names
 632         # shellcheck disable=SC2006
 633         eval "`$_parset_PARALLEL_PRG -k --_parset var,"$_parset_NAME" "$@"`"
 634         # The eval returns the function!
 635     fi
 636 }