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(alues of POSIX.2 system con\214guration v)-.25 F .58(ariables, retrie)-.25 F
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278.4 S .676(iltins, which must be implemented as part of the shell to pro).2 F
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330 R 3.473(si)-.55 G(nteracti)286.016 330 Q 1.273 -.15(ve b)-.25 H(eha).15 E
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417.6 Q .904(using the sh language.)72 429.6 R .904(There e)5.904 F .904
(xist multiple incompatible implementations of the)-.15 F F1(test)3.403 E F0
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(\214les for type and other attrib)72 441.6 R .281
(utes and performs arithmetic and string comparisons.)-.2 F .281
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453.6 R .868(vior w)-.2 F .868(as speci\214ed in terms of the number of ar)-.1
F .867(guments to the com-)-.18 F 3.803(mand. POSIX.2)72 465.6 R 1.303
(dictates e)3.803 F 1.303(xactly what will happen when four or fe)-.15 F 1.303
(wer ar)-.25 F 1.303(guments are gi)-.18 F -.15(ve)-.25 G 3.803(nt).15 G(o)
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(een omitted as being `).15 F(`be)-.74 E .28(yond its scope.)-.15 F 4.26 -.74
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(Comparison)2.5 E F0 .693(This section compares features of bash, sh, and ksh \
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72 616.8 R .366(\214rst three sections pro)2.866 F .366(vide a progressi)-.15 F
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(mand line editing standardized by POSIX.2.)72 207.6 Q 1.69
(Readline is fully customizable.)97 223.2 R 1.691
(In addition to the basic commands and k)6.69 F 1.991 -.15(ey b)-.1 H 1.691
(indings, the library).15 F(allo)72 235.2 Q .83
(ws users to de\214ne additional k)-.25 F 1.13 -.15(ey b)-.1 H .83
(indings using a startup \214le.).15 F(The)5.83 E F2(inputr)3.329 E(c)-.37 E F0
.829(\214le, which def)4.995 F .829(aults to the)-.1 F(\214le)72 247.2 Q F2
(~/.inputr)4.287 E(c)-.37 E F0 4.287(,i)1.666 G 4.287(sr)137.43 247.2 S 1.788(\
ead each time readline initializes, permitting users to maintain a consistent \
interf)148.937 247.2 R(ace)-.1 E .547(across a set of programs.)72 259.2 R .546
(Readline includes an e)5.546 F .546(xtensible interf)-.15 F .546
(ace, so each program using the library can)-.1 F .23(add its o)72 271.2 R .23
(wn bindable commands and program-speci\214c k)-.25 F .531 -.15(ey b)-.1 H
2.731(indings. Bash).15 F .231(uses this f)2.731 F .231
(acility to add bindings)-.1 F(that perform history e)72 283.2 Q
(xpansion or shell w)-.15 E(ord e)-.1 E(xpansions on the current input line.)
-.15 E .707(Readline interprets a number of v)97 298.8 R .706
(ariables which further tune its beha)-.25 F(vior)-.2 E 5.706(.V)-.55 G .706
(ariables e)408.432 298.8 R .706(xist to control)-.15 F .157
(whether or not eight-bit characters are directly read as input or con)72 310.8
R -.15(ve)-.4 G .158(rted to meta-pre\214x).15 F .158(ed k)-.15 F .458 -.15
(ey s)-.1 H .158(equences \(a).15 F(meta-pre\214x)72 322.8 Q 1.575(ed k)-.15 F
1.875 -.15(ey s)-.1 H 1.575
(equence consists of the character with the eighth bit zeroed, preceded by the)
.15 F F2(meta-)4.074 E(pr)72 334.8 Q(e\214x)-.37 E F0(character)4.45 E 2.784
(,u)-.4 G .284(sually escape, which selects an alternate k)145.374 334.8 R -.15
(ey)-.1 G .285(map\), to decide whether to output characters).15 F .485
(with the eighth bit set directly or as a meta-pre\214x)72 346.8 R .485(ed k)
-.15 F .784 -.15(ey s)-.1 H .484(equence, whether or not to wrap to a ne).15 F
2.984(ws)-.25 G(creen)482.35 346.8 Q .157
(line when a line being edited is longer than the screen width, the k)72 358.8
R -.15(ey)-.1 G .158(map to which subsequent k).15 F .458 -.15(ey b)-.1 H
(indings).15 E .531(should apply)72 370.8 R 3.031(,o)-.65 G 3.031(re)133.802
370.8 S -.15(ve)144.353 370.8 S 3.031(nw).15 G .531
(hat happens when readline w)168.894 370.8 R .531(ants to ring the terminal')
-.1 F 3.03(sb)-.55 G 3.03(ell. All)399.37 370.8 R .53(of these v)3.03 F
(ariables)-.25 E(can be set in the inputrc \214le.)72 382.8 Q .284
(The startup \214le understands a set of C preprocessor)97 398.4 R(-lik)-.2 E
2.785(ec)-.1 G .285(onditional constructs which allo)329.49 398.4 R 2.785(wv)
-.25 G(ariables)472.9 398.4 Q .12(or k)72 410.4 R .42 -.15(ey b)-.1 H .119(ind\
ings to be assigned based on the application using readline, the terminal curr\
ently being used, or).15 F .316(the editing mode.)72 422.4 R .317
(Users can add program-speci\214c bindings to mak)5.317 F 2.817(et)-.1 G .317
(heir li)352.808 422.4 R -.15(ve)-.25 G 2.817(se).15 G 2.817(asier: here)
396.922 422.4 R .317(are bindings to)2.817 F(edit the v)72 434.4 Q(alue of)-.25
E F1 -.74(PA)2.5 G(TH)-.21 E F0(and double-quote the current or pre)2.5 E
(vious w)-.25 E(ord:)-.1 E/F3 10/Courier@0 SF 6(#M)97 452.4 S
(acros that are convenient for shell interaction)115 452.4 Q($if Bash)97 464.4
Q 6(#e)97 476.4 S(dit the path)115 476.4 Q
("\\C-xp": "PATH=${PATH}\\e\\C-e\\C-a\\ef\\C-f")97 488.4 Q 6(#p)97 500.4 S
(repare to type a quoted word -- insert open and close double quotes)115 500.4
Q 6(#a)97 512.4 S(nd move to just after the open quote)115 512.4 Q
("\\C-x\\"": "\\"\\"\\C-b")97 524.4 Q 6(#Q)97 536.4 S
(uote the current or previous word)115 536.4 Q("\\C-xq": "\\eb\\"\\ef\\"")97
548.4 Q($endif)97 560.4 Q F0 .322(There is a readline command to re-read the \
\214le, so users can edit the \214le, change some bindings, and be)72 582 R
(gin)-.15 E(to use them almost immediately)72 594 Q(.)-.65 E .851
(Bash implements the)97 609.6 R F1(bind)3.351 E F0 -.2(bu)3.351 G .851
(iltin for more dyamic control of readline than the startup \214le permits.).2
F F1(Bind)72 621.6 Q F0 .167(is used in se)2.667 F -.15(ve)-.25 G .167(ral w)
.15 F 2.667(ays. In)-.1 F F2(list)2.667 E F0 .167
(mode, it can display the current k)4.333 F .466 -.15(ey b)-.1 H .166
(indings, list all the readline edit-).15 F .149(ing directi)72 633.6 R -.15
(ve)-.25 G 2.649(sa).15 G -.25(va)132.798 633.6 S .149
(ilable for binding, list which k).25 F -.15(ey)-.1 G 2.649(si).15 G -1.9 -.4
(nv o)282.352 633.6 T .349 -.1(ke a g).4 H -2.15 -.25(iv e).1 H 2.65(nd).25 G
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(utput the current set of k)396.02 633.6 R -.15(ey)-.1 G .526(bindings in a fo\
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5.526 E F2(batc)3.026 E(h)-.15 E F0 .526(mode, it reads a series)4.692 F .71
(of k)72 657.6 R 1.01 -.15(ey b)-.1 H .71
(indings directly from a \214le and passes them to readline.).15 F .71
(In its most common usage,)5.71 F F1(bind)3.21 E F0(tak)3.21 E .71(es a)-.1 F
.534(single string and passes it directly to readline, which interprets the li\
ne as if it had just been read from the)72 669.6 R(inputrc \214le.)72 681.6 Q
(Both k)5 E .3 -.15(ey b)-.1 H(indings and v).15 E
(ariable assignments can appear in the string gi)-.25 E -.15(ve)-.25 G 2.5(nt)
.15 G(o)424.4 681.6 Q F1(bind)2.5 E F0(.)A .401(The readline library also pro)
97 697.2 R .402(vides an interf)-.15 F .402(ace for)-.1 F F2(wor)2.902 E 2.902
(dc)-.37 G(ompletion)328.546 697.2 Q F0 5.402(.W)C .402(hen the)385.888 697.2 R
F2(completion)2.902 E F0(character)4.568 E 1.261(\(usually T)72 709.2 R 1.261
(AB\) is typed, readline looks at the w)-.93 F 1.26
(ord currently being entered and computes the set of \214le-)-.1 F .523
(names of which the current w)72 721.2 R .523(ord is a v)-.1 F .523
(alid pre\214x.)-.25 F .524
(If there is only one possible completion, the rest of the)5.523 F EP
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/F0 10/Times-Roman@0 SF 2.5(-8-)279.67 48 S .358
(characters are inserted directly)72 84 R 2.858(,o)-.65 G .358(therwise the co\
mmon pre\214x of the set of \214lenames is added to the current)205.232 84 R
-.1(wo)72 96 S 3.199(rd. A).1 F .699(second T)3.199 F .699(AB character entere\
d immediately after a non-unique completion causes readline to list)-.93 F
1.814(the possible completions; there is an option to ha)72 108 R 2.113 -.15
(ve t)-.2 H 1.813(he list displayed immediately).15 F 6.813(.R)-.65 G 1.813
(eadline pro)436.517 108 R(vides)-.15 E .482
(hooks so that applications can pro)72 120 R .482
(vide speci\214c types of completion before the def)-.15 F .483
(ault \214lename completion)-.1 F .132(is attempted.)72 132 R .132
(This is quite \215e)5.132 F .132(xible, though it is not completely user)-.15
F 2.632(-programmable. Bash,)-.2 F .132(for e)2.632 F .132(xample, can)-.15 F
.37(complete \214lenames, command names \(including aliases, b)72 144 R .37
(uiltins, shell reserv)-.2 F .37(ed w)-.15 F .37(ords, shell functions, and)-.1
F -.15(exe)72 156 S .424(cutables found in the \214le system\), shell v).15 F
.424(ariables, usernames, and hostnames.)-.25 F .423
(It uses a set of heuristics)5.424 F(that, while not perfect, is generally qui\
te good at determining what type of completion to attempt.)72 168 Q/F1 10
/Times-Bold@0 SF 2.5(4.3.4. History)72 192 R F0 .255
(Access to the list of commands pre)97 207.6 R .255(viously entered \(the)-.25
F/F2 10/Times-Italic@0 SF .255(command history)2.755 F F0 2.756(\)i)C 2.756(sp)
399.236 207.6 S(ro)410.882 207.6 Q .256(vided jointly by bash)-.15 F .095
(and the readline library)72 219.6 R 5.094(.B)-.65 G .094(ash pro)178.928 219.6
R .094(vides v)-.15 F .094(ariables \()-.25 F F1(HISTFILE)A F0(,)A F1(HISTSIZE)
2.594 E F0 2.594(,a)C(nd)382.068 219.6 Q F1(HISTCONTR)2.594 E(OL)-.3 E F0 2.594
(\)a)C .094(nd the)479.186 219.6 R F1(history)72 231.6 Q F0(and)2.825 E F1(fc)
2.825 E F0 -.2(bu)2.825 G .325(iltins to manipulate the history list.).2 F .325
(The v)5.325 F .325(alue of)-.25 F F1(HISTFILE)2.825 E F0 .326
(specifes the \214le where bash)2.826 F .128(writes the command history on e)72
243.6 R .128(xit and reads it on startup.)-.15 F F1(HISTSIZE)5.128 E F0 .128
(is used to limit the number of com-)2.628 F .346(mands sa)72 255.6 R -.15(ve)
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(vides a crude form of control o)-.15 F -.15(ve)-.15 G 2.846(rw).15 G .346
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(ve c)-.2 H .405(ommands which be).15 F .405(gin with a space; a)-.15 F -.25
(va)72 279.6 S .339(lue of).25 F F2(ignor)2.839 E(edups)-.37 E F0 .339
(means to not sa)4.505 F .64 -.15(ve c)-.2 H .34
(ommands identical to the last command sa).15 F -.15(ve)-.2 G(d.).15 E F1
(HISTCONTR)5.34 E(OL)-.3 E F0 -.1(wa)72 291.6 S 3.15(sn).1 G(amed)95.6 291.6 Q
F1(history_contr)3.15 E(ol)-.18 E F0 .65(in earlier v)3.15 F .649
(ersions of bash; the old name is still accepted for backw)-.15 F .649
(ards com-)-.1 F(patibility)72 303.6 Q 5.723(.T)-.65 G(he)121.803 303.6 Q F1
(history)3.223 E F0 .724(command can read or write \214les containing the hist\
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5.895 E F1(fc)3.395 E F0 -.2(bu)3.395 G .895
(iltin, adopted from POSIX.2 and the K).2 F .894(orn Shell, allo)-.35 F .894
(ws display and re-e)-.25 F -.15(xe)-.15 G(cution,).15 E .461
(with optional editing, of commands from the history list.)72 327.6 R .462
(The readline library of)5.462 F .462(fers a set of commands to)-.25 F .657(se\
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(he)476.403 339.6 Q F2(his-)3.157 E(tory)72 351.6 Q F0(library)4.196 E 2.53(,g)
-.65 G .03(enerally incorporated directly into the readline library)128.346
351.6 R 2.53(,i)-.65 G .03(mplements a f)350.636 351.6 R .031
(acility for history recall,)-.1 F -.15(ex)72 363.6 S .594(pansion, and re-e)
.15 F -.15(xe)-.15 G .594(cution of pre).15 F .594(vious commands v)-.25 F .594
(ery similar to csh \(`)-.15 F .593(`bang history')-.74 F .593
(', so called because)-.74 F(the e)72 375.6 Q
(xclamation point introduces a history substitution\):)-.15 E/F3 10/Courier@0
SF 6($e)97 393.6 S(cho a b c d e)115 393.6 Q 6(abcde)97 405.6 S 6($!)97 417.6 S
6(!fghi)115 417.6 S(echo a b c d e f g h i)97 429.6 Q 6(abcdefghi)97 441.6 S 6
($!)97 453.6 S(-2)115 453.6 Q(echo a b c d e)97 465.6 Q 6(abcde)97 477.6 S 6
($e)97 489.6 S(cho !-2:1-4)115 489.6 Q(echo a b c d)97 501.6 Q 6(abcd)97 513.6
S F0 1.456(The command history is only sa)72 535.2 R -.15(ve)-.2 G 3.957(dw).15
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G 3.957(oi)352.804 535.2 S 3.957(ti)364.541 535.2 S 3.957(sn)374.058 535.2 S
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F0 .701(There are a number of con)97 586.8 R -.15(ve)-.4 G .701(nience v).15 F
.701(ariables that bash interprets to mak)-.25 F 3.2(el)-.1 G .7(ife easier)
402.76 586.8 R 5.7(.T)-.55 G .7(hese include)453.59 586.8 R F1(FIGNORE)72 598.8
Q F0 3.973(,w)C 1.473(hich is a set of \214lename suf)132.363 598.8 R<8c78>-.25
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(xclude when completing \214lenames;)-.15 F F1(HOSTTYPE)72 610.8 Q F0 3.03(,w)C
.53(hich is automatically set to a string describing the type of hardw)139.21
610.8 R .53(are on which bash is cur)-.1 F(-)-.2 E .76(rently e)72 622.8 R -.15
(xe)-.15 G(cuting;).15 E F1(OSTYPE)3.26 E F0 3.26(,t)C 3.26(ow)191.76 622.8 S
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(sr)-.55 G(unning)476.22 622.8 Q 1.354
(on \(great for putting architecture-speci\214c binary directories into the)72
634.8 R F1 -.74(PA)3.854 G(TH)-.21 E F0 1.354(\); and)B F1(IGNOREEOF)3.854 E F0
3.854(,w)C(hose)485.67 634.8 Q -.25(va)72 646.8 S .062
(lue indicates the number of consecuti).25 F .362 -.15(ve E)-.25 H .062
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R .113(ay to k)-.1 F .113(eep yourself from being logged out accidentally)-.1 F
5.113(.T)-.65 G(he)344.285 658.8 Q F1(auto_r)2.613 E(esume)-.18 E F0 -.25(va)
2.613 G .113(riable alters the w).25 F(ay)-.1 E .409
(the shell treats simple command names: if job control is acti)72 670.8 R -.15
(ve)-.25 G 2.909(,a).15 G .409(nd this v)335.516 670.8 R .409
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/F0 10/Times-Roman@0 SF 2.5(-9-)279.67 48 S/F1 10/Times-Bold@0 SF 2.5
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(ay to generate arbitrary strings that share a common pre\214x or suf)-.1 F
<8c78>-.25 E 1.893(\(pathname e)72 111.6 R 1.893
(xpansion requires that the \214lenames e)-.15 F 1.892(xist\), bash implements)
-.15 F/F2 10/Times-Italic@0 SF(br)4.392 E 1.892(ace e)-.15 F(xpansion)-.2 E F0
4.392(,ac)C(apability)469 111.6 Q(pick)72 123.6 Q .496(ed up from csh.)-.1 F
.496(Brace e)5.496 F .496(xpansion is similar to pathname e)-.15 F .496
(xpansion, b)-.15 F .497(ut the strings generated need not)-.2 F 1.107
(correspond to e)72 135.6 R 1.107(xisting \214les.)-.15 F 3.607(Ab)6.107 G
1.107(race e)207.655 135.6 R 1.107(xpression consists of an optional)-.15 F F2
(pr)3.606 E(eamble)-.37 E F0 3.606(,f)1.666 G(ollo)419.286 135.6 Q 1.106
(wed by a pair of)-.25 F 2.809
(braces enclosing a series of comma-separated strings, and an optional)72 147.6
R F2(postamble)5.31 E F0 7.81(.T)1.666 G 2.81(he preamble is)440.06 147.6 R(pr\
epended to each string within the braces, and the postamble is then appended t\
o each resulting string:)72 159.6 Q/F3 10/Courier@0 SF 6($e)97 177.6 S
(cho a{d,c,b}e)115 177.6 Q(ade ace abe)97 189.6 Q F1 2.5(4.3.7. Pr)72 219.6 R
(ompt Customization)-.18 E F0 .077(One of the more popular interacti)97 235.2 R
.376 -.15(ve f)-.25 H .076(eatures that bash pro).15 F .076
(vides is the ability to customize the prompt.)-.15 F(Both)72 247.2 Q F1(PS1)
3.305 E F0(and)3.305 E F1(PS2,)3.305 E F0 .805
(the primary and secondary prompts, are e)3.305 F .805
(xpanded before being displayed.)-.15 F -.15(Pa)5.805 G(rameter).15 E .324
(and v)72 259.2 R .324(ariable e)-.25 F .324
(xpansion is performed when the prompt string is e)-.15 F .323
(xpanded, so the v)-.15 F .323(alue of an)-.25 F 2.823(ys)-.15 G .323(hell v)
454.217 259.2 R(ariable)-.25 E .728(can be put into the prompt \(e.g.,)72 271.2
R F1($SHL)3.228 E(VL)-.92 E F0 3.228(,w)C .728(hich indicates ho)258.564 271.2
R 3.228(wd)-.25 G .729(eeply the current shell is nested\).)342.988 271.2 R
(Bash)5.729 E 1.895
(specially interprets characters in the prompt string preceded by a backslash.)
72 283.2 R 1.895(Some of these backslash)6.895 F .874
(escapes are replaced with the current time, the date, the current w)72 295.2 R
.874(orking directory)-.1 F 3.374(,t)-.65 G .874(he username, and the)416.958
295.2 R .781(command number or history number of the command being entered.)72
307.2 R .78(There is e)5.781 F -.15(ve)-.25 G 3.28(nab).15 G .78
(ackslash escape to)429.13 307.2 R .007
(cause the shell to change its prompt when running as root after an)72 319.2 R
F2(su)2.507 E F0 5.007(.B)C .008(efore printing each primary prompt,)360.388
319.2 R .27(bash e)72 331.2 R .27(xpands the v)-.15 F(ariable)-.25 E F1(PR)2.77
E(OMPT_COMMAND)-.3 E F0 .269(and, if it has a v)2.77 F .269(alue, e)-.25 F -.15
(xe)-.15 G .269(cutes the e).15 F .269(xpanded v)-.15 F .269(alue as a)-.25 F
.04(command, allo)72 343.2 R .041(wing additional prompt customization.)-.25 F
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(xample, this assignment causes the current user)311.964 343.2 R(,)-.4 E .99
(the current host, the time, the last component of the current w)72 355.2 R
.989(orking directory)-.1 F 3.489(,t)-.65 G .989(he le)402.954 355.2 R -.15(ve)
-.25 G 3.489(lo).15 G 3.489(fs)443.412 355.2 S .989(hell nesting,)454.121 355.2
R(and the history number of the current command to be embedded into the primar\
y prompt:)72 367.2 Q F3 6($P)97 385.2 S
(S1='\\u@\\h [\\t] \\W\($SHLVL:\\!\)\\$ ')115 385.2 Q
(chet@odin [21:03:44] documentation\(2:636\)$ cd ..)97 397.2 Q
(chet@odin [21:03:54] src\(2:637\)$)97 409.2 Q F0 .619
(The string being assigned is surrounded by single quotes so that if it is e)72
430.8 R(xported,)-.15 E F1(SHL)3.119 E(VL)-.92 E F0 .619(will be updated)3.119
F(by a child shell:)72 442.8 Q F3
(chet@odin [21:13:35] src\(2:638\)$ export PS1)97 460.8 Q
(chet@odin [21:17:40] src\(2:639\)$ bash)97 472.8 Q
(chet@odin [21:17:46] src\(3:696\)$)97 484.8 Q F0(The)72 506.4 Q F1(\\$)2.5 E
F0(escape is displayed as `)2.5 E(`)-.74 E F1($)A F0 1.48 -.74('' w)D
(hen running as a normal user).74 E 2.5(,b)-.4 G(ut as `)342.08 506.4 Q(`)-.74
E F1(#)A F0 1.48 -.74('' w)D(hen running as root.).74 E F1 2.5(4.3.8. POSIX)72
530.4 R(Mode)2.5 E F0 .46(Although bash is intended to be POSIX.2 compliant, t\
here are areas in which the def)97 546 R .46(ault beha)-.1 F .46(vior is)-.2 F
1.168(not compatible with the standard.)72 558 R -.15(Fo)6.169 G 3.669(ru).15 G
1.169(sers who wish to operate in a strict POSIX.2 en)238.85 558 R 1.169
(vironment, bash)-.4 F .61(implements a)72 570 R F2 .61(POSIX mode)3.11 F F0
5.61(.W)C .61(hen this mode is acti)199.42 570 R -.15(ve)-.25 G 3.109(,b).15 G
.609(ash modi\214es its def)303.727 570 R .609(ault operation where it dif)-.1
F(fers)-.25 E .066(from POSIX.2 to match the standard.)72 582 R .067
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(yo)-.15 G 3.714(ft)103.894 96 S 1.214(he v)113.718 96 R 1.214
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(vior when set \(re)-.2 F -.05(ga)-.15 G 1.214(rdless of their v).05 F 1.215
(alue\) will be made)-.25 F 6(options settable with)72 108 R F2(shopt)8.5 E F0
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E(w_null_glob_expansion)-.1 E F0(,)A F2(glob_dot_\214lenames)72 120 Q F0 2.5
(,a)C(nd)163.67 120 Q F2(MAIL_W)2.5 E(ARNING)-1.2 E F0(.)A F2 2.5(5.4. V)72 144
R(ariables and V)-.92 E(ariable Expansion)-.92 E F0 .047
(Bash-2.0 will implement se)97 159.6 R -.15(ve)-.25 G .048(ral ne).15 F 2.548
(wv)-.25 G .048(ariable e)252.988 159.6 R 2.548(xpansions. These)-.15 F .048
(will answer se)2.548 F -.15(ve)-.25 G .048(ral of the most per).15 F(-)-.2 E
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172.582 171.6 R .213(will be possible to `)2.713 F .212(`indirectly reference')
-.74 F 2.712('av)-.74 G .212(ariable with an e)398.534 171.6 R(xpansion,)-.15 E
(lik)72 183.6 Q 3.01(eu)-.1 G(sing)94.91 183.6 Q/F3 10/Courier@0 SF .51
(eval \\$${name})3.01 F F0 .51(to reference a v)3.01 F .51(ariable named by)
-.25 F F3(${name})3.01 E F0 5.51(.E)C .51(xpansions will be a)394.32 183.6 R
-.25(va)-.2 G(ilable).25 E .462(to retrie)72 195.6 R .762 -.15(ve s)-.25 H .462
(ubstrings of v).15 F .461(ariables in an)-.25 F F1(awk)2.961 E F0(-lik)A 2.961
(em)-.1 G .461(anner: starting at a speci\214c inde)277.692 195.6 R .461
(x, retrie)-.15 F .461(ving some num-)-.25 F .941
(ber of characters or the rest of the string.)72 207.6 R .941
(It will be possible to retrie)5.941 F 1.241 -.15(ve s)-.25 H .941
(equences of array elements lik).15 F(e)-.1 E .354(this, too.)72 219.6 R .354
(It w)5.354 F .354(ould be nice to ha)-.1 F .654 -.15(ve a w)-.2 H .354
(ay to replace portions of a v).05 F .353
(ariable matching a pattern the same w)-.25 F(ay)-.1 E(leading or trailing sub\
strings are presently stripped; that capability may be a)72 231.6 Q -.25(va)-.2
G(ilable.).25 E .453(Another ne)97 247.2 R 2.953(we)-.25 G .453
(xpansion will pro)156.376 247.2 R .453(vide a w)-.15 F .454
(ay to create strings containing arbitrary characters, which is)-.1 F(incon)72
259.2 Q -.15(ve)-.4 G 1.636(nient in the current v).15 F 4.136(ersion. W)-.15 F
1.635(ords of the form $')-.8 F F1(string)A F0 4.135('w)C 1.635(ill e)355.145
259.2 R 1.635(xpand to)-.15 F F1(string)4.135 E F0 1.635(with backslash-)4.135
F 1.231(escaped characters in)72 271.2 R F1(string)3.731 E F0 1.231
(replaced as speci\214ed by the ANSI C standard.)3.731 F 1.232
(As with other single-quoted)6.232 F
(shell strings, the only character that may not appear in)72 283.2 Q F1(string)
2.5 E F0(is a single quote.)2.5 E 1.436(The shell v)97 298.8 R 1.436
(ariables will change also.)-.25 F 3.936(An)6.436 G 1.936 -.25(ew va)272.052
298.8 T(riable).25 E F2(HISTIGNORE)3.936 E F0 1.435(will supersede)3.936 F F2
(HISTCON-)3.935 E(TR)72 310.8 Q(OL)-.3 E F0(.)A F2(HISTIGNORE)5.327 E F0 .327
(is the history analogy of)2.827 F F2(FIGNORE)2.828 E F0 2.828(:ac)C .328
(olon-separated list of patterns specifying)339.938 310.8 R 1.082
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(The special pattern '&' will match the pre)6.081 F 1.081
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(HISTCONTR)4.068 E(OL)-.3 E F1(ignor)4.068 E(edups)-.37 E F0(beha)5.734 E(vior)
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334.8 Q(vior)-.2 E .395(will lose their special meaning.)72 346.8 R -1.11(Va)
5.395 G .395(riables such as)1.11 F F2(notify)2.895 E F0(and)2.895 E F2(noclob)
2.895 E(ber)-.1 E F0 .395(which pro)2.895 F .395(vide functionality a)-.15 F
-.25(va)-.2 G(il-).25 E .931
(able via other mechanisms will no longer be treated specially)72 358.8 R 5.931
(.O)-.65 G .931(ther v)340.06 358.8 R .932(ariables will be folded into)-.25 F
F2(shopt)3.432 E F0(.)A(The)72 370.8 Q F2(history_contr)5.519 E(ol)-.18 E F0
(and)5.519 E F2(hostname_completion_\214le)5.519 E F0 -.25(va)5.519 G 3.019
(riables, superseded by).25 F F2(HISTCONTR)5.518 E(OL)-.3 E F0(and)5.518 E F2
(HOSTFILE)72 382.8 Q F0(respecti)2.5 E -.15(ve)-.25 G(ly).15 E 2.5(,w)-.65 G
(ill be remo)185.12 382.8 Q -.15(ve)-.15 G(d.).15 E F2 2.5(5.5. Readline)72
406.8 R F0(Naturally)97 422.4 Q 2.94(,t)-.65 G .44(here will be impro)142.34
422.4 R -.15(ve)-.15 G .441(ments to readline as well.).15 F .441
(All of the POSIX.2)5.441 F F1(vi)2.941 E F0 .441(-mode editing com-)B .33
(mands will be implemented; missing commands lik)72 434.4 R 2.829(e`)-.1 G .329
(m' to sa)290.599 434.4 R .629 -.15(ve t)-.2 H .329
(he current cursor position \().15 F F1(mark)A F0 2.829(\)a)C .329(nd the)
478.951 434.4 R .36(`@' command for macro e)72 446.4 R .36(xpansion will be a)
-.15 F -.25(va)-.2 G 2.861(ilable. The).25 F .361
(ability to set the mark and e)2.861 F .361(xchange the current)-.15 F .764
(cursor position \()72 458.4 R F1(point)A F0 3.264(\)a)C .764
(nd mark will be added to the readline emacs mode as well.)170.672 458.4 R .763
(Since there are com-)5.764 F .196
(mands to set the mark, commands to manipulate the re)72 470.4 R .197
(gion \(the characters between the point and the mark\))-.15 F .111(will be a)
72 482.4 R -.25(va)-.2 G 2.611(ilable. Commands).25 F(ha)2.611 E .411 -.15
(ve b)-.2 H .11
(een added to the readline emacs mode for more complete ksh compati-).15 F
(bility)72 494.4 Q 2.5(,s)-.65 G(uch as the C-])101.36 494.4 Q F1(c)A F0
(character search command.)2.5 E F2 2.5(5.6. Con\214guration)72 518.4 R F0 .318
(Bash w)97 534 R .318
(as the \214rst GNU program to completely autocon\214gure.)-.1 F .319
(Its autocon\214guration mechanism pre-)5.319 F(dates)72 546 Q F1(autoconf)4.07
E F0 4.07(,t)C 1.569
(he current GNU con\214guration program, and needs updating.)140.97 546 R 1.569
(Bash-2.0 may include an)6.569 F .603
(autoconf-based con\214guration script, if necessary ne)72 558 R 3.103(wf)-.25
G .603(unctionality can be added to autoconf, or its limita-)294.476 558 R
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(The POSIX mode will be impro)97 609.6 R -.15(ve)-.15 G 4.131(di).15 G 4.131
(nb)254.26 609.6 S 1.631(ash-2.0; it will pro)268.391 609.6 R 1.631
(vide a more complete superset of the)-.15 F(POSIX standard.)72 621.6 Q -.15
(Fo)5 G 2.5(rt).15 G(he \214rst time, bash will recognize the e)163.79 621.6 Q
(xistance of the POSIX.2)-.15 E F1(special)2.5 E F0 -.2(bu)2.5 G(iltins.).2 E
2.627(An)97 637.2 S .627 -.25(ew t)111.847 637.2 T .127(rap v).25 F(alue,)-.25
E F2(DEB)2.627 E(UG)-.1 E F0 2.627(,w)C .128(ill be present, as in ksh.)218.405
637.2 R .128(Commands speci\214ed with a)5.128 F F2(DEB)2.628 E(UG)-.1 E F0
.128(trap will)2.628 F 1.908(be e)72 649.2 R -.15(xe)-.15 G 1.908
(cuted after e).15 F -.15(ve)-.25 G 1.908(ry simple command.).15 F 1.908
(Since this mak)6.908 F 1.908(es shell script deb)-.1 F 1.908
(uggers possible, I hope to)-.2 F(include a bash deb)72 661.2 Q
(ugger in the bash-2.0 release.)-.2 E F2 2.5(6. A)72 685.2 R -.1(va)-1 G
(ilability).1 E F0 5.997(The current v)97 700.8 R 5.997(ersion of bash is a)
-.15 F -.25(va)-.2 G 5.998(ilable for anon).25 F 5.998
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/F0 10/Times-Roman@0 SF 2.5(-1)277.17 48 S 2.5(3-)288 48 S/F1 10/Times-Bold@0
SF 2.5(7. Conclusion)72 84 R F0 .755(This paper has presented an o)97 99.6 R
-.15(ve)-.15 G(rvie).15 E 3.255(wo)-.25 G 3.255(fb)259.27 99.6 S .755
(ash, compared its features with those of other shells, and)270.855 99.6 R
(hinted at features in the ne)72 111.6 Q(xt release, bash-2.0.)-.15 E .483
(Bash is a solid replacement for sh.)97 127.2 R .483(It is suf)5.483 F .483
(\214ciently portable to run on nearly e)-.25 F -.15(ve)-.25 G .484(ry v).15 F
.484(ersion of)-.15 F/F2 9/Times-Roman@0 SF(UNIX)2.984 E F0 .514
(from 4.3 BSD to SVR4.2, and se)72 139.2 R -.15(ve)-.25 G(ral).15 E F2(UNIX)
3.013 E F0 -.1(wo)3.013 G(rkalik).1 E .513(es, and rob)-.1 F .513
(ust enough to replace sh on most of those)-.2 F .771(systems, It is v)72 151.2
R .771(ery close to POSIX.2-conformant in POSIX mode, and is getting f)-.15 F
(aster)-.1 E 5.771(.I)-.55 G 3.272(ti)436.684 151.2 S 3.272(sn)445.516 151.2 S
.772(ot, unfortu-)457.678 151.2 R(nately)72 163.2 Q 2.663(,g)-.65 G .163
(etting smaller)105.953 163.2 R 2.663(,b)-.4 G .163(ut there are man)170.399
163.2 R 2.663(yo)-.15 G .163(ptional features.)248.101 163.2 R .163(It is v)
5.163 F .162(ery easy to b)-.15 F .162(uild a small subset to use as)-.2 F 2.5
(ad)72 175.2 S(irect replacement for /bin/sh.)83.94 175.2 Q .909
(Bash has thousands of users w)97 190.8 R .909(orldwide, all of whom ha)-.1 F
1.209 -.15(ve h)-.2 H .91(elped to mak).15 F 3.41(ei)-.1 G 3.41(tb)409.34 190.8
S(etter)420.53 190.8 Q 5.91(.A)-.55 G .91(nother testa-)453.38 190.8 R
(ment to the bene\214ts of free softw)72 202.8 Q(are.)-.1 E F1 2.5(8. Refer)72
226.8 R(ences)-.18 E F0 .432([1] S. R. Bourne, `)72 242.4 R .432(`UNIX T)-.74 F
.432(ime-Sharing System:)-.35 F .431(The UNIX Shell')5.431 F(',)-.74 E/F3 10
/Times-Italic@0 SF .431(Bell System T)2.931 F(ec)-.92 E .431(hnical J)-.15 F
(ournal)-.25 E F0 2.931(,5)C(7\(6\),)484.84 242.4 Q
(July-August, 1978, pp. 1971-1990.)72 254.4 Q .736([2] Morris Bolsk)72 270 R
3.237(ya)-.15 G .737(nd Da)153.22 270 R .737(vid K)-.2 F(orn,)-.35 E F3 .737
(The K)3.237 F .737(ornShell Command and Pr)-.4 F -.1(og)-.45 G -.15(ra).1 G
.737(mming Langua).15 F -.1(ge)-.1 G F0 3.237(,P).1 G .737(rentice Hall,)
453.833 270 R(1989.)72 282 Q .142([3] Bill Jo)72 297.6 R 1.442 -.65(y, A)-.1 H
2.642(nI).65 G .141(ntroduction to the C Shell,)140.428 297.6 R F3 .141
(UNIX User')2.641 F 2.641(sS)-.4 G .141(upplementary Documents)309.346 297.6 R
F0 2.641(,U)C(ni)424.328 297.6 Q -.15(ve)-.25 G .141(rsity of Califor).15 F(-)
-.2 E(nia at Berk)72 309.6 Q(ele)-.1 E 1.3 -.65(y, 1)-.15 H(986.).65 E .283
([4] IEEE,)72 325.2 R F3 .283(IEEE Standar)2.783 F 2.783(df)-.37 G .283
(or Information T)179.692 325.2 R(ec)-.92 E(hnolo)-.15 E .283(gy -- P)-.1 F
.283(ortable Oper)-.8 F .283(ating System Interface \(POSIX\) P)-.15 F(art)-.8
E(2: Shell and Utilities)72 337.2 Q F0 2.5(,1)C(992.)165.06 337.2 Q F1 2.5
(9. A)72 361.2 R(uthor Inf)-.5 E(ormation)-.25 E F0 .937(Chet Rame)97 376.8 R
3.437(yi)-.15 G 3.437(sas)153.724 376.8 S(oftw)172.818 376.8 Q .936
(are engineer w)-.1 F .936(orking at Case W)-.1 F .936(estern Reserv)-.8 F
3.436(eU)-.15 G(ni)393.43 376.8 Q -.15(ve)-.25 G(rsity).15 E 5.936(.H)-.65 G
3.436(eh)443.036 376.8 S .936(as a B.S. in)455.912 376.8 R .072
(Computer Engineering and an M.S. in Computer Science, both from CWR)72 388.8 R
2.573(U. He)-.4 F .073(has been w)2.573 F .073(orking on bash)-.1 F
(for six years, and the primary maintainer for one.)72 400.8 Q EP
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