Unified · Split
| @@ -301,6 +301,29 @@ The operator is invoked and its value substituted. · 300 unmodified lines | |||
| 301 | See | 301 | See |
| 302 | .IR "Built-in Commands" , | 302 | .IR "Built-in Commands" , |
| 303 | below, for more information on builtins. | 303 | below, for more information on builtins. |
| 304 | .HP | ||
| 305 | .BI <{ command } | ||
| 306 | .HP | ||
| 307 | .BI >{ command } | ||
| 308 | .br | ||
| 309 | The | ||
| 310 | .I command | ||
| 311 | is executed asynchronously with its standard output or standard input | ||
| 312 | connected to a pipe. | ||
| 313 | The value of the argument is the name of a file | ||
| 314 | referring to the other end of the pipe. | ||
| 315 | This allows the construction of | ||
| 316 | non-linear pipelines. | ||
| 317 | For example, the following runs two commands | ||
| 318 | .B old | ||
| 319 | and | ||
| 320 | .B new | ||
| 321 | and uses | ||
| 322 | .B cmp | ||
| 323 | to compare their outputs | ||
| 324 | .EX | ||
| 325 | cmp <{old} <{new} | ||
| 326 | .EE | ||
| 304 | .PD | 327 | .PD |
| 305 | .SS Free Carets | 328 | .SS Free Carets |
| 306 | In most circumstances, | 329 | In most circumstances, |
| @@ -394,6 +417,12 @@ may be redirected from a file by the sequence · 87 unmodified lines | |||
| 394 | or by the sequence | 417 | or by the sequence |
| 395 | .BI <> file \f1, | 418 | .BI <> file \f1, |
| 396 | which opens the file for writing as well as reading. | 419 | which opens the file for writing as well as reading. |
| 420 | Note that if | ||
| 421 | .I file | ||
| 422 | is in fact a parsed braced block, the redirection will be treated as | ||
| 423 | pipe to the given command - it is identical to the | ||
| 424 | .B "<{}" | ||
| 425 | operator mentioned above. | ||
| 397 | .PP | 426 | .PP |
| 398 | Redirections may be applied to a file-descriptor other than standard input | 427 | Redirections may be applied to a file-descriptor other than standard input |
| 399 | or output by qualifying the redirection operator | 428 | or output by qualifying the redirection operator |
| @@ -463,17 +463,10 @@ its standard input is connected; otherwise file descriptor · 462 unmodified lines | |||
| 463 | is connected. | 463 | is connected. |
| 464 | .B Pipe | 464 | .B Pipe |
| 465 | yields the name of a file that can be opened to access | 465 | yields the name of a file that can be opened to access |
| 466 | the other end of the pipe. This allows the construction | 466 | the other end of the pipe. Note that this command is now |
| 467 | of non-linear pipelines. For example, the following runs two commands | 467 | deprecated in favour of the |
| 468 | .B old | 468 | .B <{} |
| 469 | and | 469 | redirection operator built in to the shell. |
| 470 | .B new | ||
| 471 | and uses | ||
| 472 | .B cmp | ||
| 473 | to compare their outputs | ||
| 474 | .EX | ||
| 475 | cmp ${pipe from {old}} ${pipe from {new}} | ||
| 476 | .EE | ||
| 477 | .TP | 470 | .TP |
| 478 | .B ${split} | 471 | .B ${split} |
| 479 | .B Split | 472 | .B Split |