%%Page: 5 5%%BeginPageSetupBP%%EndPageSetup/F0 10/Times-Roman@0 SF(-5-)282.17 48 Q(can be set in the inputrc \214le.)72 84 Q .284(The startup \214le understands a set of C preprocessor)97 99.6 R(-lik)-.2 E 2.785(ec)-.1 G .285(onditional constructs which allo)-2.785 F2.785(wv)-.25 G(ariables)-3.035 E .12(or k)72 111.6 R .42 -.15(ey b)-.1H .119(indings to be assigned based on the application using readline, \the terminal currently being used, or).15 F .338(the editing mode.)72123.6 R .338(Users can add program-speci\214c bindings to mak)5.338 F2.838(et)-.1 G .338(heir li)-2.838 F -.15(ve)-.25 G 2.838(se).15 G 2.838(asier: I)-2.838 F(ha)2.838 E .639 -.15(ve b)-.2 H .339(indings that).15F(let me edit the v)72 135.6 Q(alue of)-.25 E/F1 10/Times-Bold@0 SF($P)2.5 E -.95(AT)-.74 G(H).95 E F0(and double-quote the current or pre)2.5E(vious w)-.25 E(ord:)-.1 E/F2 10/Courier@0 SF 6(#M)97 153.6 S(acros that are convenient for shell interaction)-6 E($if Bash)97 165.6Q 6(#e)97 177.6 S(dit the path)-6 E("\\C-xp": "PATH=${PATH}\\e\\C-e\\C-a\\ef\\C-f")97 189.6 Q 6(#p)97 201.6S(repare to type a quoted word -- insert open and close double)-6 E 6(#q)97 213.6 S(uotes and move to just after the open quote)-6 E("\\C-x\\"": "\\"\\"\\C-b")97 225.6 Q 6(#Q)97 237.6 S(uote the current or previous word)-6 E("\\C-xq": "\\eb\\"\\ef\\"")97249.6 Q($endif)97 261.6 Q F0 .322(There is a readline command to re-rea\d the \214le, so users can edit the \214le, change some bindings, and b\e)72 283.2 R(gin)-.15 E(to use them almost immediately)72 295.2 Q(.)-.65E .851(Bash implements the)97 310.8 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)72 322.8 Q F0 .25(is used in se)2.75 F -.15(ve)-.25 G .25(ral w).15 F 2.75(ays. In)-.1 F/F3 10/Times-Italic@0 SF(list)2.75 E F0 .25(mode, it can display the current k)2.75 F .55 -.15(ey b)-.1 H .25(indings, list all the readline edit-).15 F .149(ing directi)72334.8 R -.15(ve)-.25 G 2.649(sa).15 G -.25(va)-2.849 G .149(ilable for binding, list which k).25 F -.15(ey)-.1 G 2.649(si).15 G-1.9 -.4(nv o)-2.649 H .349 -.1(ke a g).4 H -2.15 -.25(iv e).1 H 2.65(nd).25 G(irecti)-2.65 E -.15(ve)-.25 G 2.65(,o).15 G 2.65(ro)-2.65 G.15(utput the current set of k)-2.65 F -.15(ey)-.1 G .042(bindings in a\ format that can be incorporated directly into an inputrc \214le.)72346.8 R(In)5.041 E F3(batc)2.541 E(h)-.15 E F0 .041(mode, it reads a series of)2.541 F -.1(ke)72 358.8 S 2.858(yb)-.05 G.359(indings directly from a \214le and passes them to readline.)-2.858F .359(In its most common usage,)5.359 F F1(bind)2.859 E F0(tak)2.859 E.359(es a sin-)-.1 F 1.117(gle string and passes it directly to readlin\e, which interprets the line as if it had just been read from the)72370.8 R(inputrc \214le.)72 382.8 Q(Both k)5 E .3 -.15(ey b)-.1 H(indings and v).15 E(ariable assignments may appear in the string gi)-.25 E -.15(ve)-.25 G 2.5(nt).15 G(o)-2.5 E F1(bind)2.5 E F0(.)A .53(The readline library also pro)97 398.4 R .53(vides an interf)-.15 F .53(ace for)-.1 F F3(wor)3.03 E 3.03(dc)-.37 G(ompletion)-3.03 E F0 5.53(.W)C .53(hen the)-5.53 F F3(completion)3.03 E F0(character)3.03 E 1.261(\(usually T)72 410.4 R 1.261(AB\) 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)72 422.4 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 .358(characters are inserted directly)72 434.4 R 2.858(,o)-.65 G .358(therw\ise the common pre\214x of the set of \214lenames is added to the curre\nt)-2.858 F -.1(wo)72 446.4 S 3.199(rd. A).1 F .699(second T)3.199 F.699(AB character entered immediately after a non-unique completion cau\ses readline to list)-.93 F 1.814(the possible completions; there is an option to ha)72 458.4 R 2.113-.15(ve t)-.2 H 1.813(he list displayed immediately).15 F 6.813(.R)-.65G 1.813(eadline pro)-6.813 F(vides)-.15 E .482(hooks so that applications can pro)72 470.4 R .482(vide speci\214c types of completion before the def)-.15 F .483(ault \214lename completion)-.1 F .132(is attempted.)72 482.4 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 \(including aliases, b)72 494.4R .37(uiltins, shell reserv)-.2 F .37(ed w)-.15 F .37(ords, shell functions, and)-.1 F -.15(exe)72 506.4 S .424(cutables found in the \214le system\), 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 genera\lly quite good at determining what type of completion to attempt.)72518.4 Q F1 2.5(4.4. History)72 542.4 R F0 .144(Access to the list of commands pre)97 558 R .144(viously entered \(the)-.25 F F3 .144(command history)2.644 F F0 2.644(\)i)C 2.644(sp)-2.644 G(ro)-2.644 E .144(vided jointly by Bash)-.15 F .078(and the readline library)72 570 R 5.077(.B)-.65 G .077(ash pro)-5.077 F.077(vides v)-.15 F .077(ariables \()-.25 F F1($HISTFILE)A F0(,)A F1($HISTSIZE)2.577 E F0 2.577(,a)C(nd)-2.577 E F1($HISTCONTR)2.577 E(OL)-.3 E F0 2.577(\)a)C(nd)-2.577 E(the)72 582 Q F1(history)2.89 E F0(and)2.89 E F1(fc)2.89 E F0 -.2(bu)2.89 G .39(iltins to manipulate the history list.).2 F .391(The v)5.391 F .391(alue of)-.25 F F1($HISTFILE)2.891 E F0 .391(specifes the \214le where)2.891 F .49(Bash writes the command history on e)72 594 R .489(xit and reads it on startup.)-.15 F F1($HISTSIZE)5.489 E F0 .489(is used to limit the number)2.989 F .642(of commands sa)72 606 R -.15(ve)-.2 G 3.142(di).15 G 3.142(nt)-3.142 G .642(he history)-3.142 F(.)-.65 E F1($HISTCONTR)5.642 E(OL)-.3 E F0(pro)3.142 E .642(vides a crude form of control o)-.15 F -.15(ve)-.15 G 3.142(rw).15 G.642(hich com-)-3.142 F .025(mands are sa)72 618 R -.15(ve)-.2 G 2.525(do).15 G 2.525(nt)-2.525 G .025(he history list: a v)-2.525 F .025(alue of)-.25 F F3(ignor)2.525 E(espace)-.37 E F0 .025(means to not sa)2.525 F .324 -.15(ve c)-.2 H .024(ommands which be).15 F .024(gin with a)-.15 F .927(space; a v)72 630 R .927(alue of)-.25 F F3(ignor)3.427 E(edups)-.37 E F0 .927(means to not sa)3.427 F 1.228 -.15(ve c)-.2 H .928(ommands identical to the last command sa).15 F -.15(ve)-.2 G(d.).15 E F1($HIST)5.928 E(-)-.92 E(CONTR)72 642 Q(OL)-.3 E F0 -.1(wa)3.778 G 3.778(sn).1 G(amed)-3.778 E F1($history_contr)3.778 E(ol)-.18 E F0 1.278(in earlier v)3.778 F 1.278(ersions of Bash; the old name is still accepted for)-.15 F(backw)72 654Q .575(ards compatibility)-.1 F 5.575(.T)-.65 G(he)-5.575 E F1(history)3.075 E F0 .575(command can read or write \214les containing the history list and dis-)3.075 F .167(play the current list contents.)72 666 R(The)5.167 E F1(fc)2.667 E F0 -.2(bu)2.667 G .167(iltin, adopted from POSIX.2 and the K).2F .167(orn Shell, allo)-.35 F .167(ws display and)-.25 F(re-e)72 678 Q-.15(xe)-.15 G .58(cution, with optional editing, of commands from the history list.).15 F.58(The readline library of)5.58 F .58(fers a set of)-.25 F 1.255(comma\nds to search the history list for a portion of the current input line \or a string typed by the user)72 690 R(.)-.55 E(Finally)72 702 Q 2.535(,t)-.65 G(he)-2.535 E F3(history)2.535 E F0(library)2.535 E 2.535(,g)-.65 G .036(enerally incorporated directly into the readline library)-2.535 F 2.536(,i)-.65 G .036(mplements a f)-2.536 F .036(acility for)-.1 F 1.023(history recall, e)72 714 R 1.022(xpansion, and re-e)-.15 F-.15(xe)-.15 G 1.022(cution of pre).15 F 1.022(vious commands v)-.25 F1.022(ery similar to csh \(\231bang history\232, so)-.15 F(called because the e)72 726 Q(xclamation point introduces a history substitution\):)-.15 E EP%%Page: 6 6%%BeginPageSetupBP%%EndPageSetup/F0 10/Times-Roman@0 SF(-6-)282.17 48 Q/F1 10/Courier@0 SF 6($e)97 84 S(cho a b c d e)-6 E 6(abcde)97 96 S 6($!)97 108 S 6(!fghi)-6 G(echo a b c d e f g h i)97 120 Q 6(abcdefghi)97 132 S 6($!)97 144 S(-2)-6 E(echo a b c d e)97 156 Q 6(abcde)97 168 S 6($e)97 180 S(cho !-2:1-4)-6 E(echo a b c d)97 192 Q 6(abcd)97 204 S F0 1.456(The command history is only sa)72 225.6 R -.15(ve)-.2 G 3.957(dw).15 G1.457(hen the shell is interacti)-3.957 F -.15(ve)-.25 G 3.957(,s).15 G3.957(oi)-3.957 G 3.957(ti)-3.957 G 3.957(sn)-3.957 G 1.457(ot a)-3.957F -.25(va)-.2 G 1.457(ilable for use by shell).25 F(scripts.)72 237.6 Q/F2 10/Times-Bold@0 SF 2.5(4.5. New)72 261.6 R(Shell V)2.5 E(ariables)-.92 E F0 .59(There are a number of con)97 277.2 R -.15(ve)-.4 G .589(nience v).15 F .589(ariables that Bash interprets to mak)-.25 F 3.089(el)-.1 G .589(ife easier)-3.089 F 5.589(.T)-.55 G .589(hese include)-5.589 F F2(FIGNORE)72 289.2 Q F0 3.973(,w)C 1.473(hich is a set of \214lename suf)-3.973 F<8c78>-.25 E 1.474(es identifying \214les to e)-.15 F 1.474(xclude when completing \214lenames;)-.15 F F2(HOSTTYPE)72 301.2 Q F02.932(,w)C .432(hich is automatically set to a string describing the type of hardw)-2.932 F .431(are on which Bash is cur)-.1 F(-)-.2 E .335(rently e)72313.2 R -.15(xe)-.15 G(cuting;).15 E F2(command_oriented_history)2.835 EF0 2.835(,w)C .335(hich directs Bash to sa)-2.835 F .635 -.15(ve a)-.2 H.336(ll lines of a multiple-line com-).15 F 1.071(mand such as a)72325.2 R/F3 10/Times-Italic@0 SF(while)3.571 E F0(or)3.571 E F3(for)3.571E F0 1.071(loop in a single history entry)3.571 F 3.57(,a)-.65 G(llo)-3.57 E 1.07(wing easy re-editing; and)-.25 F F2(IGNOREEOF)3.57 E F0(,)A.747(whose v)72 337.2 R .747(alue indicates the number of consecuti)-.25F 1.047 -.15(ve E)-.25 H .747(OF characters that an interacti).15 F1.048 -.15(ve s)-.25 H .748(hell will read before).15 F -.15(ex)72 349.2S 1.432(iting \255 an easy w).15 F 1.432(ay to k)-.1 F 1.432(eep yourself from being logged out accidentally)-.1 F 6.432(.T)-.65 G(he)-6.432 E F2(auto_r)3.932 E(esume)-.18 E F0 -.25(va)3.932 G(riable).25 E .571(alters the w)72 361.2 R .571(ay the shell treats simple command names: if job control is acti)-.1 F-.15(ve)-.25 G 3.071(,a).15 G .571(nd this v)-3.071 F .571(ariable is set, sin-)-.25 F(gle-w)72 373.2 Q .239(ord simple commands \without redirections cause the shell to \214rst look for and restart a \suspended job)-.1 F(with that name before starting a ne)72 385.2 Q 2.5(wp)-.25 G(rocess.)-2.5 E F2 2.5(4.6. Brace)72 409.2 R(Expansion)2.5 EF0 .653(Since sh of)97 424.8 R .653(fers no con)-.25 F -.15(ve)-.4 G.653(nient w).15 F .653(ay to generate arbitrary strings that share a common pre\214x or suf)-.1 F<8c78>-.25 E 2.124(\(\214lename e)72 436.8 R 2.124(xpansion requires that the \214lenames e)-.15 F 2.123(xist\), Bash implements)-.15 F F3(br)4.623 E 2.123(ace e)-.15 F(xpansion)-.2 E F0 4.623(,ac)C(apability)-4.623 E(pick)72 448.8 Q .773(ed up from csh.)-.1 F .774(Brace e)5.773 F .774(xpansion is similar to \214lename e)-.15 F .774(xpansion, b)-.15 F .774(ut the strings generated need not)-.2 F 1.211(correspond to e)72 460.8R 1.211(xisting \214les.)-.15 F 3.711(Ab)6.211 G 1.211(race e)-3.711 F1.211(xpression consists of an optional)-.15 F F3(pr)3.71 E(eamble)-.37E F0 3.71(,f)C(ollo)-3.71 E 1.21(wed by a pair of)-.25 F 2.938(braces enclosing a series of comma-separated strings, and an optional)72 472.8 R F3(postamble)5.438 E F0 7.938(.T)C 2.938(he preamble is)-7.938 F(prepended to each string within the braces, and the postamble \is then appended to each resulting string:)72 484.8 Q F1 6($e)97 502.8 S(cho a{d,c,b}e)-6 E(ade ace abe)97 514.8 Q F0 .306(As this e)72 536.4 R.306(xample demonstrates, the results of brace e)-.15 F .305(xpansion are not sorted, as the)-.15 F 2.805(ya)-.15 G .305(re by \214lename e)-2.805 F(xpan-)-.15 E(sion.)72 548.4 Q F2 2.5(4.7. Pr)72 572.4 R(ocess Substitution)-.18 E F0 .457(On systems that can support it, Bash pro)97 588 R .457(vides a f)-.15 F.457(acility kno)-.1 F .458(wn as)-.25 F F3(pr)2.958 E .458(ocess substitution)-.45 F F0 5.458(.P)C .458(rocess sub-)-5.458 F .347(stitution is similar to command substitution in that its speci\214cati\on includes a command to e)72 600 R -.15(xe)-.15 G .346(cute, b).15 F.346(ut the)-.2 F .181(shell does not collect the command')72 612 R2.681(so)-.55 G .181(utput and insert it into the command line.)-2.681 F(Rather)5.181 E 2.681(,B)-.4 G .182(ash opens a pipe)-2.681 F 1.861(to the command, which is run in the background.)72 624 R 1.861(The shell uses named pipes \(FIFOs\) or the)6.861 F F3(/de)4.361 E(v/fd)-.15 E F0 .961(method of naming open \214les to e)72 636 R .962(x\pand the process substitution to a \214lename which connects to the pip\e)-.15 F .104(when opened.)72 648 R .103(This \214lename becomes the result of the e)5.104 F 2.603(xpansion. Process)-.15 F .103(substitution can be used to com-)2.603 F(pare the outputs of tw)72 660 Q 2.5(od)-.1 G(if)-2.5 E(ferent v)-.25 E(ersions of an application as part of a re)-.15 E(gression test:)-.15 EF1 6($c)97 678 S(mp <\(old_prog\) <\(new_prog\))-6 E EP%%Page: 7 7%%BeginPageSetupBP%%EndPageSetup/F0 10/Times-Roman@0 SF(-7-)282.17 48 Q/F1 10/Times-Bold@0 SF 2.5(4.8. Pr)72 84 R(ompt Customization)-.18 E F0 2.229(One of the more popular interacti)97 99.6 R 2.529 -.15(ve f)-.25 H2.229(eatures that Bash pro).15 F 2.23(vides is the ability to customize the)-.15 F 3.234(prompt. Both)72111.6 R F1($PS1)3.234 E F0(and)3.234 E F1($PS2,)3.234 E F0 .734(the primary and secondary prompts, are e)3.234 F .733(xpanded before being displayed.)-.15 F -.15(Pa)72 123.6 S .804(rameter and v).15 F .804(ariable e)-.25 F .805(xpansion is performed when the prompt string is e)-.15 F .805(xpanded, so an)-.15 F 3.305(ys)-.15 G .805(hell v)-3.305 F(ariable)-.25E .729(can be put into the prompt \(e.g.,)72 135.6 R F1($SHL)3.228 E(VL)-.92 E F0 3.228(,w)C .728(hich indicates ho)-3.228 F 3.228(wd)-.25 G.728(eeply the current shell is nested\).)-3.228 F(Bash)5.728 E 1.895(s\pecially interprets characters in the prompt string preceded by a backs\lash.)72 147.6 R 1.895(Some of these backslash)6.895 F .874(escapes are replaced with the current time, the date, the current w)72159.6 R .874(orking directory)-.1 F 3.373(,t)-.65 G .873(he username, and the)-3.373 F .78(command number or history number of the command being entered.)72 171.6R .781(There is e)5.781 F -.15(ve)-.25 G 3.281(nab).15 G .781(ackslash escape to)-3.281 F .007