plan9.ps

早期freebsd实现

(case [1-9] 10)2 702 1 1224 5284 t
(sec=$1 secn=$1)1 756 1 1440 5394 t
(case -f)1 378 1 1224 5504 t
(c=f s=f)1 378 1 1440 5614 t
(case -[qwnt])1 648 1 1224 5724 t
(cmd=$1)1440 5834 w
(case -T*)1 432 1 1224 5944 t
(T=$1)1440 6054 w
(case -*)1 378 1 1224 6164 t
(opt=\($opt $1\))1 702 1 1440 6274 t
(})1224 6384 w
(shift)1224 6494 w
(})1008 6604 w
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6 pagesetup
10 R f
(- 6 -)2 166 1 2797 480 t
10 B f
(16. Functions)1 598 1 720 840 t
10 R f
(Functions may be defined by typing)5 1441 1 720 996 t
9 CW f
(fn)1008 1166 w
9 I f
(name)1170 1166 w
9 CW f
({)1419 1166 w
9 I f
(commands)1527 1166 w
9 CW f
(})1966 1166 w
10 R f
(Subsequently, whenever a command named)4 1795 1 720 1346 t
10 I f
(name)2550 1346 w
10 R f
(is encountered, the remainder of the command's argu-)7 2238 1 2802 1346 t
( to)1 106(ment list will assigned)3 910 2 720 1466 t
10 CW f
($*)1764 1466 w
10 R f
(and)1912 1466 w
10 I f
(rc)2084 1466 w
10 R f
(will execute the)2 638 1 2195 1466 t
10 I f
(commands)2861 1466 w
10 R f
( value of)2 355(. The)1 233 2 3288 1466 t
10 CW f
($*)3904 1466 w
10 R f
(will be restored on com-)4 988 1 4052 1466 t
( example:)1 391(pletion. For)1 492 2 720 1586 t
9 CW f
(fn g {)2 324 1 1008 1756 t
(gre -e $1 *.[hcyl])3 972 1 1224 1866 t
(})1008 1976 w
10 R f
(defines)720 2156 w
10 CW f
(g)1033 2156 w
10 I f
(pattern)1118 2156 w
10 R f
(to look for occurrences of)4 1030 1 1432 2156 t
10 I f
(pattern)2487 2156 w
10 R f
(in all program source files in the current directory.)8 2015 1 2801 2156 t
(Function definitions are deleted by writing)5 1707 1 720 2312 t
9 CW f
(fn)1008 2482 w
9 I f
(name)1170 2482 w
10 R f
(with no function body.)3 911 1 720 2662 t
10 B f
( execution)1 430(17. Command)1 625 2 720 2902 t
10 R f
( very little about what)4 897(Up to now we've said)4 892 2 720 3058 t
10 I f
(rc)2539 3058 w
10 R f
( the command name)3 822( If)1 121(does to execute a simple command.)5 1445 3 2652 3058 t
(is the name of a function defined using)7 1570 1 720 3178 t
10 CW f
(fn)2317 3178 w
10 R f
( if it is the name of a built-)8 1082( Otherwise,)1 487(, the function is executed.)4 1034 3 2437 3178 t
(in command, the built-in is executed directly by)7 1964 1 720 3298 t
10 I f
(rc)2716 3298 w
10 R f
( if the name contains a)5 936(. Otherwise,)1 517 2 2799 3298 t
10 CW f
(/)4284 3298 w
10 R f
(, it is taken to be)5 696 1 4344 3298 t
(the name of a binary program and is executed using)9 2155 1 720 3418 t
10 I f
(exec)2910 3418 w
10 R f
( the name contains no)4 907(\(2\). If)1 267 2 3086 3418 t
10 CW f
(/)4294 3418 w
10 R f
(, then directories)2 686 1 4354 3418 t
(mentioned in the variable)3 1018 1 720 3538 t
10 CW f
($path)1763 3538 w
10 R f
(are searched until an executable file is found.)7 1806 1 2088 3538 t
10 B f
( commands)1 486(18. Built-in)1 504 2 720 3778 t
10 R f
( executed internally by)3 924(Several commands are)2 909 2 720 3934 t
10 I f
(rc)2582 3934 w
10 R f
(because they are difficult or impossible to implement oth-)8 2346 1 2694 3934 t
(erwise.)720 4054 w
10 CW f
(. [-i])1 360 1 720 4210 t
10 I f
(file ...)1 228 1 1140 4210 t
10 R f
(Execute commands from)2 1008 1 970 4330 t
10 I f
(file)2008 4330 w
10 R f
(.)2136 4330 w
10 CW f
($*)2216 4330 w
10 R f
( reminder of the argument list follow-)6 1545(is set for the duration to the)6 1129 2 2366 4330 t
(ing)970 4450 w
10 I f
(file)1125 4450 w
10 R f
(.)1253 4450 w
10 CW f
($path)1330 4450 w
10 R f
(is used to search for)4 806 1 1657 4450 t
10 I f
(file)2490 4450 w
10 R f
(. Option)1 354 1 2618 4450 t
10 CW f
(-i)2998 4450 w
10 R f
(indicates interactive input)2 1034 1 3144 4450 t
10 S f
(-)4204 4450 w
10 R f
(a prompt \(found in)3 755 1 4285 4450 t
10 CW f
($prompt)970 4570 w
10 R f
(\) is printed before each command is read.)7 1651 1 1390 4570 t
10 CW f
(builtin)720 4726 w
10 I f
(command ...)1 488 1 1200 4726 t
10 R f
(Execute)970 4846 w
10 I f
(command)1316 4846 w
10 R f
(as usual except that any function named)6 1597 1 1729 4846 t
10 I f
(command)3351 4846 w
10 R f
( example,)1 388( For)1 189(is ignored.)1 422 3 3764 4846 t
9 CW f
(fn cd{)1 324 1 1258 5016 t
(builtin cd $* && pwd)4 1080 1 1474 5126 t
(})1258 5236 w
10 R f
(defines a replacement for the)4 1177 1 970 5416 t
10 CW f
(cd)2177 5416 w
10 R f
(built-in \(see below\) that announces the full name of the new direc-)11 2713 1 2327 5416 t
(tory.)970 5536 w
10 CW f
(cd [)1 240 1 720 5692 t
10 I f
(dir)960 5692 w
10 CW f
(])1077 5692 w
10 R f
(Change the current directory to)4 1255 1 970 5812 t
10 I f
(dir)2252 5812 w
10 R f
( default argument is)3 802(. The)1 232 2 2369 5812 t
10 CW f
($home)3430 5812 w
10 R f
(.)3730 5812 w
10 CW f
($cdpath)3808 5812 w
10 R f
(is a list of places in)5 784 1 4256 5812 t
(which to search for)3 767 1 970 5932 t
10 I f
(dir)1762 5932 w
10 R f
(.)1879 5932 w
10 CW f
(eval [)1 360 1 720 6088 t
10 I f
(arg ...)1 239 1 1080 6088 t
10 CW f
(])1319 6088 w
10 R f
(The arguments are catenated separated by spaces into a string, read as input to)13 3159 1 970 6208 t
10 I f
(rc)4158 6208 w
10 R f
( For)1 193(, and executed.)2 606 2 4241 6208 t
(example,)970 6328 w
9 CW f
(x='$y')1258 6498 w
(y=Doody)1258 6608 w
(eval echo Howdy, $x)3 1026 1 1258 6718 t
10 R f
(would echo)1 463 1 970 6898 t
9 CW f
(Howdy, Doody)1 648 1 1258 7068 t
10 R f
(since the arguments of)3 901 1 970 7248 t
10 CW f
(eval)1896 7248 w
10 R f
(would be)1 369 1 2161 7248 t
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7 pagesetup
10 R f
(- 7 -)2 166 1 2797 480 t
9 CW f
(echo Howdy, $y)2 756 1 1258 830 t
10 R f
(after substituting for)2 816 1 970 1010 t
10 CW f
($x)1811 1010 w
10 R f
(.)1931 1010 w
10 CW f
(shift [)1 420 1 720 1166 t
10 I f
(n)1140 1166 w
10 CW f
(])1190 1166 w
10 R f
(Delete the first)2 593 1 970 1286 t
10 I f
(n)1588 1286 w
10 R f
(\(default 1\) elements of)3 906 1 1663 1286 t
10 CW f
($*)2594 1286 w
10 R f
(.)2714 1286 w
10 CW f
(wait [)1 360 1 720 1442 t
10 I f
(pid)1080 1442 w
10 CW f
(])1208 1442 w
10 R f
( given)1 263(Wait for the process with the)5 1231 2 970 1562 t
10 I f
(pid)2505 1562 w
10 R f
( no)1 141( If)1 132(to exit.)1 294 3 2674 1562 t
10 I f
(pid)3282 1562 w
10 R f
(is given, all outstanding processes are)5 1589 1 3451 1562 t
(waited for.)1 432 1 970 1682 t
10 CW f
(whatis)720 1838 w
10 I f
(name ...)1 316 1 1140 1838 t
10 R f
( each)1 209(Print the value of)3 694 2 970 1958 t
10 I f
(name)1900 1958 w
10 R f
(in a form suitable for input to)6 1189 1 2143 1958 t
10 I f
(rc)3359 1958 w
10 R f
( output is an assignment to a vari-)7 1366(. The)1 232 2 3442 1958 t
(able, the definition of a function, a call to)8 1709 1 970 2078 t
10 CW f
(builtin)2711 2078 w
10 R f
( the path name of a)5 792(for a built-in command, or)4 1085 2 3163 2078 t
( example,)1 388( For)1 189(binary program.)1 643 3 970 2198 t
9 CW f
(whatis path g cd who)4 1080 1 1258 2368 t
10 R f
(might print)1 448 1 970 2548 t
9 CW f
(path=\(. /bin /usr/bin\))2 1188 1 1258 2718 t
(fn g {gre -e $1 *.[hycl]})5 1350 1 1258 2828 t
(builtin cd)1 540 1 1258 2938 t
(/bin/who)1258 3048 w
10 CW f
(\304)720 3264 w
10 I f
(subject pattern ...)2 697 1 840 3264 t
10 R f
(The)970 3384 w
10 I f
(subject)1150 3384 w
10 R f
(is matched against each)3 945 1 1458 3384 t
10 I f
(pattern)2428 3384 w
10 R f
( a match,)2 365( On)1 172(in turn.)1 289 3 2742 3384 t
10 CW f
($status)3594 3384 w
10 R f
( Otherwise,)1 486(is set to true.)3 514 2 4040 3384 t
(it is set to)3 396 1 970 3504 t
10 CW f
('no match')1 602 1 1393 3504 t
10 R f
( The)1 207( are the same as for filename matching.)7 1582(. Patterns)1 399 3 1995 3504 t
10 I f
(patterns)4210 3504 w
10 R f
(are not sub-)2 475 1 4565 3504 t
(jected to filename replacement before the)5 1698 1 970 3624 t
10 CW f
(\304)2702 3624 w
10 R f
(command is executed, so they need not be enclosed in)9 2244 1 2796 3624 t
(quotation marks, unless of course, a literal match for)8 2102 1 970 3744 t
10 CW f
(* [)1 145 1 3097 3744 t
10 R f
(or)3267 3744 w
10 CW f
(?)3375 3744 w
10 R f
( example)1 363( For)1 189(is required.)1 449 3 3485 3744 t
9 CW f
(\304 $1 ?)2 324 1 1258 3914 t
10 R f
(matches any single character, whereas)4 1525 1 970 4094 t
9 CW f
(\304 $1 '?')2 432 1 1258 4264 t
10 R f
(only matches a literal question mark.)5 1476 1 970 4444 t
10 B f
( I/O Redirection)2 694(19. Advanced)1 603 2 720 4684 t
10 I f
(Rc)720 4840 w
10 R f
( of file descriptors other than 0 and 1 \(standard input and output\) by specifying the file)16 3472(allows redirection)1 718 2 850 4840 t
(descriptor in square brackets)3 1144 1 720 4960 t
10 CW f
([ ])1 180 1 1889 4960 t
10 R f
(after the)1 329 1 2094 4960 t
10 CW f
(<)2448 4960 w
10 R f
(or)2533 4960 w
10 CW f
(>)2641 4960 w
10 R f
( example,)1 388(. For)1 214 2 2701 4960 t
9 CW f
(cc junk.c >[2]junk.diag)2 1242 1 1008 5130 t
10 R f
(saves the compiler's diagnostics in)4 1393 1 720 5310 t
10 CW f
(junk.diag)2138 5310 w
10 R f
(.)2678 5310 w
( replaced by a copy, in the sense of)8 1471(File descriptors may be)3 959 2 720 5466 t
10 I f
(dup)3184 5466 w
10 R f
(\(2\), of an already-open file by typing, for)7 1706 1 3334 5466 t
(example)720 5586 w
9 CW f
(cc junk.c >[2=1])2 864 1 1008 5756 t
10 R f
( in conjunction with other)4 1061( is more useful)3 609( It)1 117(This replaces file descriptor 2 with a copy of file descriptor 1.)11 2533 4 720 5936 t
(redirections, like this)2 841 1 720 6056 t
9 CW f
(cc junk.c >junk.out >[2=1])3 1404 1 1008 6226 t
10 R f
( descriptor 1 to)3 629(Redirections are evaluated from left to right, so this redirects file)10 2667 2 720 6406 t
10 CW f
(junk.out)4050 6406 w
10 R f
(, then points)2 510 1 4530 6406 t
( contrast,)1 366( By)1 167(file descriptor 2 at the same file.)6 1289 3 720 6526 t
9 CW f
(cc junk.c >[2=1] >junk.out)3 1404 1 1008 6696 t
10 R f
( \(presumably the terminal\), and then directs file)7 2000(Redirects file descriptor 2 to a copy of file descriptor 1)10 2320 2 720 6876 t
( the first case, standard and diagnostic output will be intermixed in)11 2686( In)1 135( at a file.)3 355(descriptor 1)1 477 4 720 6996 t
10 CW f
(junk.out)4400 6996 w
10 R f
(. In)1 160 1 4880 6996 t
(the second, diagnostic output will appear on the terminal, and standard output will be sent to the file.)17 4024 1 720 7116 t
( For)1 211( using the duplication notation with an empty right-hand side.)9 2664(File descriptors may be closed by)5 1445 3 720 7272 t
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8 pagesetup
10 R f
(- 8 -)2 166 1 2797 480 t
(example,)720 840 w
9 CW f
(cc junk.c >[2=])2 810 1 1008 1010 t
10 R f
(will discard diagnostics from the compilation.)5 1838 1 720 1190 t
(Arbitrary file descriptors may be sent through a pipe by typing, for example)12 3031 1 720 1346 t
9 CW f
(cc junk.c |[2] grep -v '\303$')5 1458 1 1008 1516 t
10 R f
( that the output of)4 779( Note)1 261( the C compiler's output.)4 1065(This deletes those ever-so-annoying blank lines from)6 2215 4 720 1696 t
10 CW f
(grep)720 1816 w
10 R f
(still appears on file descriptor 1.)5 1287 1 985 1816 t
( a pipe to some file descriptor other than zero.)9 1871(Very occasionally you may wish to connect the input side of)10 2449 2 720 1972 t
(The notation)1 508 1 720 2092 t
9 CW f
(cmd1 |[5=19] cmd2)2 918 1 1008 2262 t
10 R f
(creates a pipeline with)3 895 1 720 2442 t
10 CW f
(cmd1)1640 2442 w
10 R f
('s file descriptor 5 connected through a pipe to)8 1863 1 1880 2442 t
10 CW f
(cmd2)3768 2442 w