src/env_parallel.pod

   1 #!/usr/bin/perl -w
   2
   3 # SPDX-FileCopyrightText: 2021-2024 Ole Tange, http://ole.tange.dk and Free Software and Foundation, Inc.
   4 # SPDX-License-Identifier: GFDL-1.3-or-later
   5 # SPDX-License-Identifier: CC-BY-SA-4.0
   6
   7 =encoding utf8
   8
   9 =head1 NAME
  10
  11 env_parallel - export environment to GNU parallel
  12
  13
  14 =head1 SYNOPSIS
  15
  16 B<env_parallel> [--record-env|--session|--end-session]
  17   [options for GNU Parallel]
  18
  19
  20 =head1 DESCRIPTION
  21
  22 B<env_parallel> is a shell function that exports the current
  23 environment to GNU B<parallel>.
  24
  25 If the shell function is not loaded, a dummy script will be run
  26 instead that explains how to install the function.
  27
  28 B<env_parallel> is 100 ms slower at startup than pure GNU B<parallel>,
  29 and takes up to 30% longer to start a job (typically 15 ms).
  30
  31 Due to the problem with environment space (see below) you are
  32 recommended only to transfer the environment that you need.
  33
  34 To help you do that, you can mark names that should not be
  35 transferred. This can be done with either B<--session> or
  36 B<--record-env>.
  37
  38   # Record the "clean" environment (this only needs to be run once)
  39   env_parallel --record-env
  40
  41   # Optionally edit ~/.parallel/ignored_vars (only needed once)
  42
  43   # Define whatever you want to use
  44   myfunc() { myalias and functions $myvar work. $1.; }
  45   alias myalias='echo Aliases'
  46   myvar='and variables'
  47
  48   # Use --env _ to only transfer the names not in the "empty" environment
  49   env_parallel --env _ -S localhost myfunc ::: Hooray
  50
  51 Or:
  52
  53   # Do --record-env into $PARALLEL_IGNORED_NAMES
  54   env_parallel --session
  55
  56   # Define whatever you want to use
  57   myfunc() { myalias and functions $myvar work. $1.; }
  58   alias myalias='echo Aliases'
  59   myvar='and variables'
  60
  61   # env_parallel will not export names in $PARALLEL_IGNORED_NAMES
  62   env_parallel -S localhost myfunc ::: Hooray
  63
  64   # Optionally
  65   env_parallel --end-session
  66
  67 In B<csh> B<--session> is not supported:
  68
  69   # Record the "clean" environment - this only needs to be run once
  70   env_parallel --record-env
  71
  72   # Optionally edit ~/.parallel/ignored_vars - only needed once
  73
  74   # Define whatever you want to use
  75   alias myalias 'echo Aliases $myvar \!*.'
  76   set myvar='and variables'
  77
  78   # Use --env _ to only transfer the names not in the "empty" environment
  79   env_parallel --env _ -S localhost myalias ::: work
  80
  81 =head2 Environment space
  82
  83 By default B<env_parallel> will export all environment variables,
  84 arrays, aliases, functions and shell options (see details for the
  85 individual shells below).
  86
  87 But this only works if the size of the current environment is smaller
  88 than the maximal length of a command and smaller than half of the max
  89 if running remotely. E.g. The max size of Bash's command is 128 KB, so
  90 B<env_parallel> will fail if 'B<set | wc -c>' is bigger than 128
  91 KB. Technically the limit is in execve(1) which IPC::open3 uses.
  92
  93 Bash completion functions are well-known for taking up well over 128
  94 KB of environment space and the primary reason for causing
  95 B<env_parallel> to fail.
  96
  97 Instead you can use B<--env> to specify which variables, arrays,
  98 aliases and functions to export as this will only export those with
  99 the given name. Or follow the recommended usage in shown in
 100 DESCRIPTION.
 101
 102
 103 =head1 OPTIONS
 104
 105 Same as GNU B<parallel> in addition to these:
 106
 107 =over 4
 108
 109 =item B<--end-session>
 110
 111 Undo last B<--session>
 112
 113
 114 =item B<--record-env>
 115
 116 Record all names currently defined to be ignored every time running
 117 B<env_parallel> in the future.
 118
 119
 120 =item B<--session>
 121
 122 Ignore all names currently defined. Aliases, variables, arrays, and
 123 functions currently defined will not be transferred.
 124
 125 But names defined I<after> running B<parallel --session> I<will> be
 126 transferred.
 127
 128 This is only valid in the running shell, and can be undone with
 129 B<parallel --end-session>.
 130
 131 You can run multiple B<--session> inside each other:
 132
 133   env_parallel --session
 134   var=not
 135   # var is transferred
 136   env_parallel -Slocalhost 'echo var is $var' ::: ignored
 137   env_parallel --session
 138   # var is not transferred
 139   env_parallel -Slocalhost 'echo var is $var' ::: ignored
 140   env_parallel --end-session
 141   # var is transferred again
 142   env_parallel -Slocalhost 'echo var is $var' ::: ignored
 143
 144
 145
 146 =back
 147
 148
 149 =head1 SUPPORTED SHELLS
 150
 151 =head2 Ash
 152
 153 =head3 Installation
 154
 155 Put this in $HOME/.profile:
 156
 157   . env_parallel.ash
 158
 159 E.g. by doing:
 160
 161   echo '. env_parallel.ash' >> $HOME/.profile
 162
 163 =head3 Supported use
 164
 165 B<--env> is supported to export only the variable, or alias with the
 166 given name. Multiple B<--env>s can be given.
 167
 168 B<--session> is supported.
 169
 170 =over 8
 171
 172 =item aliases
 173
 174   alias myecho='echo aliases'
 175   env_parallel myecho ::: work
 176   env_parallel -S server myecho ::: work
 177   env_parallel --env myecho myecho ::: work
 178   env_parallel --env myecho -S server myecho ::: work
 179
 180   alias multiline='echo multiline
 181     echo aliases'
 182   env_parallel multiline ::: work
 183   env_parallel -S server multiline ::: work
 184   env_parallel --env multiline multiline ::: work
 185   env_parallel --env multiline -S server multiline ::: work
 186
 187 =item functions
 188
 189   ash cannot list defined functions - thus is not supported.
 190
 191 =item variables
 192
 193   myvar=variables
 194   env_parallel echo '$myvar' ::: work
 195   env_parallel -S server echo '$myvar' ::: work
 196   env_parallel --env myvar echo '$myvar' ::: work
 197   env_parallel --env myvar -S server echo '$myvar' ::: work
 198
 199 =item arrays
 200
 201 Arrays are not supported by Ash.
 202
 203 =back
 204
 205 =head2 Bash
 206
 207 =head3 Installation
 208
 209 Put this in $HOME/.bashrc:
 210
 211   . env_parallel.bash
 212
 213 E.g. by doing:
 214
 215   echo '. env_parallel.bash' >> $HOME/.bashrc
 216
 217 =head3 Supported use
 218
 219 B<--env> is supported to export only the variable, alias, function, or
 220 array with the given name. Multiple B<--env>s can be given.
 221
 222 B<--session> is supported.
 223
 224 =over 8
 225
 226 =item aliases
 227
 228   alias myecho='echo aliases'
 229   env_parallel myecho ::: work
 230   env_parallel -S server myecho ::: work
 231   env_parallel --env myecho myecho ::: work
 232   env_parallel --env myecho -S server myecho ::: work
 233
 234   alias multiline='echo multiline
 235     echo aliases'
 236   env_parallel 'multiline {};
 237     echo but only when followed by a newline' ::: work
 238   env_parallel -S server 'multiline {};
 239     echo but only when followed by a newline' ::: work
 240   env_parallel --env multiline 'multiline {};
 241     echo but only when followed by a newline' ::: work
 242   env_parallel --env multiline -S server 'multiline {};
 243     echo but only when followed by a newline' ::: work
 244
 245 =item functions
 246
 247   myfunc() { echo functions $*; }
 248   env_parallel myfunc ::: work
 249   env_parallel -S server myfunc ::: work
 250   env_parallel --env myfunc myfunc ::: work
 251   env_parallel --env myfunc -S server myfunc ::: work
 252
 253 =item variables
 254
 255   myvar=variables
 256   env_parallel echo '$myvar' ::: work
 257   env_parallel -S server echo '$myvar' ::: work
 258   env_parallel --env myvar echo '$myvar' ::: work
 259   env_parallel --env myvar -S server echo '$myvar' ::: work
 260
 261 =item arrays
 262
 263   myarray=(arrays work, too)
 264   env_parallel -k echo '${myarray[{}]}' ::: 0 1 2
 265   env_parallel -k -S server echo '${myarray[{}]}' ::: 0 1 2
 266   env_parallel -k --env myarray echo '${myarray[{}]}' ::: 0 1 2
 267   env_parallel -k --env myarray -S server \
 268     echo '${myarray[{}]}' ::: 0 1 2
 269
 270 =back
 271
 272 =head3 BUGS
 273
 274 Due to a bug in Bash, aliases containing newlines must be followed by
 275 a newline in the command. Some systems are not affected by this bug,
 276 but will print a warning anyway.
 277
 278 =head2 csh (alpha testing)
 279
 280 B<env_parallel> for B<csh> breaks B<$PARALLEL>, so do not use
 281 B<$PARALLEL>.
 282
 283 =head3 Installation
 284
 285 Put this in $HOME/.cshrc:
 286
 287   source `which env_parallel.csh`
 288
 289 E.g. by doing:
 290
 291   echo 'source `which env_parallel.csh`' >> $HOME/.cshrc
 292
 293 =head3 Supported use
 294
 295 B<--env> is supported to export only the variable, alias, or
 296 array with the given name. Multiple B<--env>s can be given.
 297
 298 =over 8
 299
 300 =item aliases
 301
 302   alias myecho 'echo aliases'
 303   env_parallel myecho ::: work
 304   env_parallel -S server myecho ::: work
 305   env_parallel --env myecho myecho ::: work
 306   env_parallel --env myecho -S server myecho ::: work
 307
 308 =item functions
 309
 310 Not supported by B<csh>.
 311
 312 =item variables
 313
 314   set myvar=variables
 315   env_parallel echo '$myvar' ::: work
 316   env_parallel -S server echo '$myvar' ::: work
 317   env_parallel --env myvar echo '$myvar' ::: work
 318   env_parallel --env myvar -S server echo '$myvar' ::: work
 319
 320 =item arrays with no special chars
 321
 322   set myarray=(arrays work, too)
 323   env_parallel -k echo \$'{myarray[{}]}' ::: 1 2 3
 324   env_parallel -k -S server echo \$'{myarray[{}]}' ::: 1 2 3
 325   env_parallel -k --env myarray echo \$'{myarray[{}]}' ::: 1 2 3
 326   env_parallel -k --env myarray -S server \
 327     echo \$'{myarray[{}]}' ::: 1 2 3
 328
 329 =back
 330
 331
 332 =head2 Dash
 333
 334 =head3 Installation
 335
 336 Put this in $HOME/.profile:
 337
 338   . env_parallel.dash
 339
 340 E.g. by doing:
 341
 342   echo '. env_parallel.dash' >> $HOME/.profile
 343
 344 =head3 Supported use
 345
 346 B<--env> is supported to export only the variable, or alias with the
 347 given name. Multiple B<--env>s can be given.
 348
 349 B<--session> is supported.
 350
 351 =over 8
 352
 353 =item aliases
 354
 355   alias myecho='echo aliases'
 356   env_parallel myecho ::: work
 357   env_parallel -S server myecho ::: work
 358   env_parallel --env myecho myecho ::: work
 359   env_parallel --env myecho -S server myecho ::: work
 360
 361   alias multiline='echo multiline
 362     echo aliases'
 363   env_parallel multiline ::: work
 364   env_parallel -S server multiline ::: work
 365   env_parallel --env multiline multiline ::: work
 366   env_parallel --env multiline -S server multiline ::: work
 367
 368 =item functions
 369
 370   dash cannot list defined functions - thus is not supported.
 371
 372 =item variables
 373
 374   myvar=variables
 375   env_parallel echo '$myvar' ::: work
 376   env_parallel -S server echo '$myvar' ::: work
 377   env_parallel --env myvar echo '$myvar' ::: work
 378   env_parallel --env myvar -S server echo '$myvar' ::: work
 379
 380 =item arrays
 381
 382   dash does not support arrays.
 383
 384 =back
 385
 386
 387 =head2 fish (beta testing)
 388
 389 =head3 Installation
 390
 391 Put this in $HOME/.config/fish/config.fish:
 392
 393   source (which env_parallel.fish)
 394
 395 E.g. by doing:
 396
 397   echo 'source (which env_parallel.fish)' \
 398     >> $HOME/.config/fish/config.fish
 399
 400 =head3 Supported use
 401
 402 B<--env> is supported to export only the variable, alias, function, or
 403 array with the given name. Multiple B<--env>s can be given.
 404
 405 B<--session> is supported.
 406
 407 =over 8
 408
 409 =item aliases
 410
 411   alias myecho 'echo aliases'
 412   env_parallel myecho ::: work
 413   env_parallel -S server myecho ::: work
 414   env_parallel --env myecho myecho ::: work
 415   env_parallel --env myecho -S server myecho ::: work
 416
 417 =item functions
 418
 419   function myfunc
 420     echo functions $argv
 421   end
 422   env_parallel myfunc ::: work
 423   env_parallel -S server myfunc ::: work
 424   env_parallel --env myfunc myfunc ::: work
 425   env_parallel --env myfunc -S server myfunc ::: work
 426
 427 =item variables
 428
 429   set myvar variables
 430   env_parallel echo '$myvar' ::: work
 431   env_parallel -S server echo '$myvar' ::: work
 432   env_parallel --env myvar echo '$myvar' ::: work
 433   env_parallel --env myvar -S server echo '$myvar' ::: work
 434
 435 =item arrays
 436
 437 Arrays normally work, but fail intermitently.
 438
 439   set myarray arrays work, too
 440   env_parallel -k echo '$myarray[{}]' ::: 1 2 3
 441   env_parallel -k -S server echo '$myarray[{}]' ::: 1 2 3
 442   env_parallel -k --env myarray echo '$myarray[{}]' ::: 1 2 3
 443   env_parallel -k --env myarray -S server \
 444     echo '$myarray[{}]' ::: 1 2 3
 445
 446 =back
 447
 448
 449 =head2 ksh
 450
 451 =head3 Installation
 452
 453 Put this in $HOME/.kshrc:
 454
 455   source env_parallel.ksh
 456
 457 E.g. by doing:
 458
 459   echo 'source env_parallel.ksh' >> $HOME/.kshrc
 460
 461 =head3 Supported use
 462
 463 B<--env> is supported to export only the variable, alias, function, or
 464 array with the given name. Multiple B<--env>s can be given.
 465
 466 B<--session> is supported.
 467
 468 =over 8
 469
 470 =item aliases
 471
 472   alias myecho='echo aliases'
 473   env_parallel myecho ::: work
 474   env_parallel -S server myecho ::: work
 475   env_parallel --env myecho myecho ::: work
 476   env_parallel --env myecho -S server myecho ::: work
 477
 478   alias multiline='echo multiline
 479     echo aliases'
 480   env_parallel multiline ::: work
 481   env_parallel -S server multiline ::: work
 482   env_parallel --env multiline multiline ::: work
 483   env_parallel --env multiline -S server multiline ::: work
 484
 485 =item functions
 486
 487   myfunc() { echo functions $*; }
 488   env_parallel myfunc ::: work
 489   env_parallel -S server myfunc ::: work
 490   env_parallel --env myfunc myfunc ::: work
 491   env_parallel --env myfunc -S server myfunc ::: work
 492
 493 =item variables
 494
 495   myvar=variables
 496   env_parallel echo '$myvar' ::: work
 497   env_parallel -S server echo '$myvar' ::: work
 498   env_parallel --env myvar echo '$myvar' ::: work
 499   env_parallel --env myvar -S server echo '$myvar' ::: work
 500
 501 =item arrays
 502
 503   myarray=(arrays work, too)
 504   env_parallel -k echo '${myarray[{}]}' ::: 0 1 2
 505   env_parallel -k -S server echo '${myarray[{}]}' ::: 0 1 2
 506   env_parallel -k --env myarray echo '${myarray[{}]}' ::: 0 1 2
 507   env_parallel -k --env myarray -S server \
 508     echo '${myarray[{}]}' ::: 0 1 2
 509
 510 =back
 511
 512
 513 =head2 mksh
 514
 515 =head3 Installation
 516
 517 Put this in $HOME/.mkshrc:
 518
 519   source env_parallel.mksh
 520
 521 E.g. by doing:
 522
 523   echo 'source env_parallel.mksh' >> $HOME/.mkshrc
 524
 525 =head3 Supported use
 526
 527 B<--env> is supported to export only the variable, alias, function, or
 528 array with the given name. Multiple B<--env>s can be given.
 529
 530 B<--session> is supported.
 531
 532 =over 8
 533
 534 =item aliases
 535
 536   alias myecho='echo aliases'
 537   env_parallel myecho ::: work
 538   env_parallel -S server myecho ::: work
 539   env_parallel --env myecho myecho ::: work
 540   env_parallel --env myecho -S server myecho ::: work
 541
 542   alias multiline='echo multiline
 543     echo aliases'
 544   env_parallel multiline ::: work
 545   env_parallel -S server multiline ::: work
 546   env_parallel --env multiline multiline ::: work
 547   env_parallel --env multiline -S server multiline ::: work
 548
 549 =item functions
 550
 551   myfunc() { echo functions $*; }
 552   env_parallel myfunc ::: work
 553   env_parallel -S server myfunc ::: work
 554   env_parallel --env myfunc myfunc ::: work
 555   env_parallel --env myfunc -S server myfunc ::: work
 556
 557 =item variables
 558
 559   myvar=variables
 560   env_parallel echo '$myvar' ::: work
 561   env_parallel -S server echo '$myvar' ::: work
 562   env_parallel --env myvar echo '$myvar' ::: work
 563   env_parallel --env myvar -S server echo '$myvar' ::: work
 564
 565 =item arrays
 566
 567   myarray=(arrays work, too)
 568   env_parallel -k echo '${myarray[{}]}' ::: 0 1 2
 569   env_parallel -k -S server echo '${myarray[{}]}' ::: 0 1 2
 570   env_parallel -k --env myarray echo '${myarray[{}]}' ::: 0 1 2
 571   env_parallel -k --env myarray -S server \
 572     echo '${myarray[{}]}' ::: 0 1 2
 573
 574 =back
 575
 576
 577 =head2 pdksh
 578
 579 =head3 Installation
 580
 581 Put this in $HOME/.profile:
 582
 583   source env_parallel.pdksh
 584
 585 E.g. by doing:
 586
 587   echo 'source env_parallel.pdksh' >> $HOME/.profile
 588
 589 =head3 Supported use
 590
 591 B<--env> is supported to export only the variable, alias, function, or
 592 array with the given name. Multiple B<--env>s can be given.
 593
 594 B<--session> is supported.
 595
 596 =over 8
 597
 598 =item aliases
 599
 600   alias myecho="echo aliases";
 601   env_parallel myecho ::: work;
 602   env_parallel -S server myecho ::: work;
 603   env_parallel --env myecho myecho ::: work;
 604   env_parallel --env myecho -S server myecho ::: work
 605
 606 =item functions
 607
 608   myfunc() { echo functions $*; };
 609   env_parallel myfunc ::: work;
 610   env_parallel -S server myfunc ::: work;
 611   env_parallel --env myfunc myfunc ::: work;
 612   env_parallel --env myfunc -S server myfunc ::: work
 613
 614 =item variables
 615
 616   myvar=variables;
 617   env_parallel echo "\$myvar" ::: work;
 618   env_parallel -S server echo "\$myvar" ::: work;
 619   env_parallel --env myvar echo "\$myvar" ::: work;
 620   env_parallel --env myvar -S server echo "\$myvar" ::: work
 621
 622 =item arrays
 623
 624   myarray=(arrays work, too);
 625   env_parallel -k echo "\${myarray[{}]}" ::: 0 1 2;
 626   env_parallel -k -S server echo "\${myarray[{}]}" ::: 0 1 2;
 627   env_parallel -k --env myarray echo "\${myarray[{}]}" ::: 0 1 2;
 628   env_parallel -k --env myarray -S server \
 629     echo "\${myarray[{}]}" ::: 0 1 2
 630
 631 =back
 632
 633
 634 =head2 sh
 635
 636 =head3 Installation
 637
 638 Put this in $HOME/.profile:
 639
 640   . env_parallel.sh
 641
 642 E.g. by doing:
 643
 644   echo '. env_parallel.sh' >> $HOME/.profile
 645
 646 =head3 Supported use
 647
 648 B<--env> is supported to export only the variable, or alias with the
 649 given name. Multiple B<--env>s can be given.
 650
 651 B<--session> is supported.
 652
 653 =over 8
 654
 655 =item aliases
 656
 657   sh does not support aliases.
 658
 659 =item functions
 660
 661   myfunc() { echo functions $*; }
 662   env_parallel myfunc ::: work
 663   env_parallel -S server myfunc ::: work
 664   env_parallel --env myfunc myfunc ::: work
 665   env_parallel --env myfunc -S server myfunc ::: work
 666
 667 =item variables
 668
 669   myvar=variables
 670   env_parallel echo '$myvar' ::: work
 671   env_parallel -S server echo '$myvar' ::: work
 672   env_parallel --env myvar echo '$myvar' ::: work
 673   env_parallel --env myvar -S server echo '$myvar' ::: work
 674
 675 =item arrays
 676
 677   sh does not support arrays.
 678
 679 =back
 680
 681
 682 =head2 tcsh (alpha testing)
 683
 684 B<env_parallel> for B<tcsh> breaks B<$PARALLEL>, so do not use
 685 B<$PARALLEL>.
 686
 687 =head3 Installation
 688
 689 Put this in $HOME/.tcshrc:
 690
 691   source `which env_parallel.tcsh`
 692
 693 E.g. by doing:
 694
 695   echo 'source `which env_parallel.tcsh`' >> $HOME/.tcshrc
 696
 697 =head3 Supported use
 698
 699 B<--env> is supported to export only the variable, alias, or
 700 array with the given name. Multiple B<--env>s can be given.
 701
 702 =over 8
 703
 704 =item aliases
 705
 706   alias myecho 'echo aliases'
 707   env_parallel myecho ::: work
 708   env_parallel -S server myecho ::: work
 709   env_parallel --env myecho myecho ::: work
 710   env_parallel --env myecho -S server myecho ::: work
 711
 712 =item functions
 713
 714 Not supported by B<tcsh>.
 715
 716 =item variables
 717
 718   set myvar=variables
 719   env_parallel echo '$myvar' ::: work
 720   env_parallel -S server echo '$myvar' ::: work
 721   env_parallel --env myvar echo '$myvar' ::: work
 722   env_parallel --env myvar -S server echo '$myvar' ::: work
 723
 724 =item arrays with no special chars
 725
 726   set myarray=(arrays work, too)
 727   env_parallel -k echo \$'{myarray[{}]}' ::: 1 2 3
 728   env_parallel -k -S server echo \$'{myarray[{}]}' ::: 1 2 3
 729   env_parallel -k --env myarray echo \$'{myarray[{}]}' ::: 1 2 3
 730   env_parallel -k --env myarray -S server \
 731     echo \$'{myarray[{}]}' ::: 1 2 3
 732
 733 =back
 734
 735
 736 =head2 Zsh
 737
 738 =head3 Installation
 739
 740 Put this in $HOME/.zshrc:
 741
 742   . env_parallel.zsh
 743
 744 E.g. by doing:
 745
 746   echo '. env_parallel.zsh' >> $HOME/.zshenv
 747
 748 =head3 Supported use
 749
 750 B<--env> is supported to export only the variable, alias, function, or
 751 array with the given name. Multiple B<--env>s can be given.
 752
 753 B<--session> is supported.
 754
 755 =over 8
 756
 757 =item aliases
 758
 759   alias myecho='echo aliases'
 760   env_parallel myecho ::: work
 761   env_parallel -S server myecho ::: work
 762   env_parallel --env myecho myecho ::: work
 763   env_parallel --env myecho -S server myecho ::: work
 764
 765   alias multiline='echo multiline
 766     echo aliases'
 767   env_parallel multiline ::: work
 768   env_parallel -S server multiline ::: work
 769   env_parallel --env multiline multiline ::: work
 770   env_parallel --env multiline -S server multiline ::: work
 771
 772 =item functions
 773
 774   myfunc() { echo functions $*; }
 775   env_parallel myfunc ::: work
 776   env_parallel -S server myfunc ::: work
 777   env_parallel --env myfunc myfunc ::: work
 778   env_parallel --env myfunc -S server myfunc ::: work
 779
 780 =item variables
 781
 782   myvar=variables
 783   env_parallel echo '$myvar' ::: work
 784   env_parallel -S server echo '$myvar' ::: work
 785   env_parallel --env myvar echo '$myvar' ::: work
 786   env_parallel --env myvar -S server echo '$myvar' ::: work
 787
 788 =item arrays
 789
 790   myarray=(arrays work, too)
 791   env_parallel -k echo '${myarray[{}]}' ::: 1 2 3
 792   env_parallel -k -S server echo '${myarray[{}]}' ::: 1 2 3
 793   env_parallel -k --env myarray echo '${myarray[{}]}' ::: 1 2 3
 794   env_parallel -k --env myarray -S server \
 795     echo '${myarray[{}]}' ::: 1 2 3
 796
 797 =back
 798
 799
 800 =head1 EXIT STATUS
 801
 802 Same as GNU B<parallel>.
 803
 804
 805 =head1 AUTHOR
 806
 807 When using GNU B<env_parallel> for a publication please cite:
 808
 809 O. Tange (2018): GNU Parallel 2018, March 2018, ISBN 9781387509881,
 810 DOI: 10.5281/zenodo.1146014.
 811
 812 This helps funding further development; and it won't cost you a cent.
 813 If you pay 10000 EUR you should feel free to use GNU Parallel without citing.
 814
 815 Copyright (C) 2007-10-18 Ole Tange, http://ole.tange.dk
 816
 817 Copyright (C) 2008-2010 Ole Tange, http://ole.tange.dk
 818
 819 Copyright (C) 2010-2024 Ole Tange, http://ole.tange.dk and Free
 820 Software Foundation, Inc.
 821
 822
 823 =head1 LICENSE
 824
 825 This program is free software; you can redistribute it and/or modify
 826 it under the terms of the GNU General Public License as published by
 827 the Free Software Foundation; either version 3 of the License, or
 828 at your option any later version.
 829
 830 This program is distributed in the hope that it will be useful,
 831 but WITHOUT ANY WARRANTY; without even the implied warranty of
 832 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 833 GNU General Public License for more details.
 834
 835 You should have received a copy of the GNU General Public License
 836 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 837
 838 =head2 Documentation license I
 839
 840 Permission is granted to copy, distribute and/or modify this
 841 documentation under the terms of the GNU Free Documentation License,
 842 Version 1.3 or any later version published by the Free Software
 843 Foundation; with no Invariant Sections, with no Front-Cover Texts, and
 844 with no Back-Cover Texts.  A copy of the license is included in the
 845 file LICENSES/GFDL-1.3-or-later.txt.
 846
 847
 848 =head2 Documentation license II
 849
 850 You are free:
 851
 852 =over 9
 853
 854 =item B<to Share>
 855
 856 to copy, distribute and transmit the work
 857
 858 =item B<to Remix>
 859
 860 to adapt the work
 861
 862 =back
 863
 864 Under the following conditions:
 865
 866 =over 9
 867
 868 =item B<Attribution>
 869
 870 You must attribute the work in the manner specified by the author or
 871 licensor (but not in any way that suggests that they endorse you or
 872 your use of the work).
 873
 874 =item B<Share Alike>
 875
 876 If you alter, transform, or build upon this work, you may distribute
 877 the resulting work only under the same, similar or a compatible
 878 license.
 879
 880 =back
 881
 882 With the understanding that:
 883
 884 =over 9
 885
 886 =item B<Waiver>
 887
 888 Any of the above conditions can be waived if you get permission from
 889 the copyright holder.
 890
 891 =item B<Public Domain>
 892
 893 Where the work or any of its elements is in the public domain under
 894 applicable law, that status is in no way affected by the license.
 895
 896 =item B<Other Rights>
 897
 898 In no way are any of the following rights affected by the license:
 899
 900 =over 2
 901
 902 =item *
 903
 904 Your fair dealing or fair use rights, or other applicable
 905 copyright exceptions and limitations;
 906
 907 =item *
 908
 909 The author's moral rights;
 910
 911 =item *
 912
 913 Rights other persons may have either in the work itself or in
 914 how the work is used, such as publicity or privacy rights.
 915
 916 =back
 917
 918 =back
 919
 920 =over 9
 921
 922 =item B<Notice>
 923
 924 For any reuse or distribution, you must make clear to others the
 925 license terms of this work.
 926
 927 =back
 928
 929 A copy of the full license is included in the file as
 930 LICENCES/CC-BY-SA-4.0.txt
 931
 932
 933 =head1 DEPENDENCIES
 934
 935 B<env_parallel> uses GNU B<parallel>.
 936
 937
 938 =head1 SEE ALSO
 939
 940 B<parallel>(1), B<ash>(1), B<bash>(1), B<csh>(1), B<dash>(1),
 941 B<fish>(1), B<ksh>(1), B<pdksh>(1) B<tcsh>(1), B<zsh>(1).
 942
 943
 944 =cut