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diff --git a/man/man1/rc.html b/man/man1/rc.html new file mode 100644 index 00000000..a599adfd --- /dev/null +++ b/man/man1/rc.html @@ -0,0 +1,655 @@ +<head> +<title>rc(1) - Plan 9 from User Space</title> +<meta content="text/html; charset=utf-8" http-equiv=Content-Type> +</head> +<body bgcolor=#ffffff> +<table border=0 cellpadding=0 cellspacing=0 width=100%> +<tr height=10><td> +<tr><td width=20><td> +<tr><td width=20><td><b>RC(1)</b><td align=right><b>RC(1)</b> +<tr><td width=20><td colspan=2> + <br> +<p><font size=+1><b>NAME </b></font><br> + +<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + rc, cd, eval, exec, exit, flag, rfork, shift, wait, whatis, ., + ~ – command language<br> + +</table> +<p><font size=+1><b>SYNOPSIS </b></font><br> + +<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + <tt><font size=+1>rc</font></tt> [ <tt><font size=+1>−srdiIlxepvV</font></tt> ] [ <tt><font size=+1>−c command</font></tt> ] [ <i>file</i> [ <i>arg ...</i> ]]<br> + +</table> +<p><font size=+1><b>DESCRIPTION </b></font><br> + +<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + <i>Rc</i> is the Plan 9 shell. It executes command lines read from a + terminal or a file or, with the <tt><font size=+1>−c</font></tt> flag, from <i>rc’s</i> argument list.<br> + <p><font size=+1><b>Command Lines </b></font><br> + A command line is a sequence of commands, separated by ampersands + or semicolons (<tt><font size=+1>&</font></tt> or <tt><font size=+1>;</font></tt>), terminated by a newline. The commands are + executed in sequence from left to right. <i>Rc</i> does not wait for + a command followed by <tt><font size=+1>&</font></tt> to finish executing before starting the + following command. Whenever a command + followed by <tt><font size=+1>&</font></tt> is executed, its process id is assigned to the <i>rc</i> + variable <tt><font size=+1>$apid</font></tt>. Whenever a command <i>not</i> followed by <tt><font size=+1>&</font></tt> exits or is + terminated, the <i>rc</i> variable <tt><font size=+1>$status</font></tt> gets the process’s wait message + (see <a href="../man3/wait.html"><i>wait</i>(3)</a>); it will be the null string if the command was successful. + + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + A long command line may be continued on subsequent lines by typing + a backslash (<tt><font size=+1>\</font></tt>) followed by a newline. This sequence is treated + as though it were a blank. Backslash is not otherwise a special + character. + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + A number-sign (<tt><font size=+1>#</font></tt>) and any following characters up to (but not + including) the next newline are ignored, except in quotation marks.<br> + <p><font size=+1><b>Simple Commands </b></font><br> + A simple command is a sequence of arguments interspersed with + I/O redirections. If the first argument is the name of an <i>rc</i> function + or of one of <i>rc’s</i> built-in commands, it is executed by <i>rc</i>. Otherwise + if the name starts with a slash (<tt><font size=+1>/</font></tt>), it must be the path name + of the program to be executed. Names containing no + initial slash are searched for in a list of directory names stored + in <tt><font size=+1>$path</font></tt>. The first executable file of the given name found in + a directory in <tt><font size=+1>$path</font></tt> is the program to be executed. To be executable, + the user must have execute permission (see <a href="../man3/stat.html"><i>stat</i>(3)</a>) and the file + must be either an executable binary for the current + machine’s CPU type, or a shell script. Shell scripts begin with + a line containing the full path name of a shell (usually <tt><font size=+1>/bin/rc</font></tt>), + prefixed by <tt><font size=+1>#!</font></tt>. + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + The first word of a simple command cannot be a keyword unless + it is quoted or otherwise disguised. The keywords are<br> + + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + <tt><font size=+1>for in while if not switch fn ~ ! @<br> + </font></tt> + </table> + <p><font size=+1><b>Arguments and Variables </b></font><br> + A number of constructions may be used where <i>rc’s</i> syntax requires + an argument to appear. In many cases a construction’s value will + be a list of arguments rather than a single string. + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + The simplest kind of argument is the unquoted word: a sequence + of one or more characters none of which is a blank, tab, newline, + or any of the following:<br> + + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + <tt><font size=+1># ; & | ^ $ = ` ' { } ( ) < ><br> + </font></tt> + </table> + An unquoted word that contains any of the characters <tt><font size=+1>* ? [</font></tt> is + a pattern for matching against file names. The character <tt><font size=+1>*</font></tt> matches + any sequence of characters, <tt><font size=+1>?</font></tt> matches any single character, and + <tt><font size=+1>[</font></tt><i>class</i><tt><font size=+1>]</font></tt> matches any character in the <i>class</i>. If the first character + of <i>class</i> is <tt><font size=+1>~</font></tt>, the class is complemented. The <i>class</i> may + also contain pairs of characters separated by <tt><font size=+1>−</font></tt>, standing for + all characters lexically between the two. The character <tt><font size=+1>/</font></tt> must + appear explicitly in a pattern, as must the first character of + the path name components <tt><font size=+1>.</font></tt> and <tt><font size=+1>..</font></tt>. A pattern is replaced by a + list of arguments, one for each path name matched, except that + a + pattern matching no names is not replaced by the empty list, but + rather stands for itself. Pattern matching is done after all other + operations. Thus,<br> + + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + <tt><font size=+1>x=/tmp echo $x^/*.c<br> + </font></tt> + </table> + matches <tt><font size=+1>/tmp/*.c</font></tt>, rather than matching <tt><font size=+1>/*.c</font></tt> and then prefixing + <tt><font size=+1>/tmp</font></tt>. + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + A quoted word is a sequence of characters surrounded by single + quotes (<tt><font size=+1>'</font></tt>). A single quote is represented in a quoted word by + a pair of quotes (<tt><font size=+1>''</font></tt>). + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + Each of the following is an argument.<br> + <tt><font size=+1>(</font></tt><i>arguments</i><tt><font size=+1>)<br> + </font></tt> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + The value of a sequence of arguments enclosed in parentheses is + a list comprising the members of each element of the sequence. + Argument lists have no recursive structure, although their syntax + may suggest it. The following are entirely equivalent:<br> + + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + <tt><font size=+1>echo hi there everybody<br> + ((echo) (hi there) everybody)<br> + </font></tt> + </table> + + </table> + <tt><font size=+1>$</font></tt><i>argument<br> + </i><tt><font size=+1>$</font></tt><i>argument</i><tt><font size=+1>(</font></tt><i>subscript</i><tt><font size=+1>)<br> + </font></tt> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + The <i>argument</i> after the <tt><font size=+1>$</font></tt> is the name of a variable whose value + is substituted. Multiple levels of indirection are possible, but + of questionable utility. Variable values are lists of strings. + If <i>argument</i> is a number <i>n</i>, the value is the <i>n</i>th element of <tt><font size=+1>$*</font></tt>, + unless <tt><font size=+1>$*</font></tt> doesn’t have <i>n</i> elements, in which case the value is + empty. If <i>argument</i> is followed by a parenthesized list of subscripts, + the value substituted is a list composed of the requested elements + (origin 1). The parenthesis must follow the variable name with + no spaces. Assignments to variables are described below.<br> + + </table> + <tt><font size=+1>$#</font></tt><i>argument<br> + </i> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + The value is the number of elements in the named variable. A variable + never assigned a value has zero elements.<br> + + </table> + $"<i>argument<br> + </i> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + The value is a single string containing the components of the + named variable separated by spaces. A variable with zero elements + yields the empty string.<br> + + </table> + <tt><font size=+1>`{</font></tt><i>command</i><tt><font size=+1>}<br> + </font></tt> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + <i>rc</i> executes the <i>command</i> and reads its standard output, splitting + it into a list of arguments, using characters in <tt><font size=+1>$ifs</font></tt> as separators. + If <tt><font size=+1>$ifs</font></tt> is not otherwise set, its value is <tt><font size=+1>' \t\n'</font></tt>.<br> + + </table> + <tt><font size=+1><{</font></tt><i>command</i><tt><font size=+1>}<br> + >{</font></tt><i>command</i><tt><font size=+1>}<br> + </font></tt> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + The <i>command</i> is executed asynchronously with its standard output + or standard input connected to a pipe. The value of the argument + is the name of a file referring to the other end of the pipe. + This allows the construction of non-linear pipelines. For example, + the following runs two commands <tt><font size=+1>old</font></tt> and <tt><font size=+1>new + </font></tt>and uses <tt><font size=+1>cmp</font></tt> to compare their outputs<br> + + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + <tt><font size=+1>cmp <{old} <{new}<br> + </font></tt> + </table> + + </table> + <i>argument</i><tt><font size=+1>^</font></tt><i>argument<br> + </i> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + The <tt><font size=+1>^</font></tt> operator concatenates its two operands. If the two operands + have the same number of components, they are concatenated pairwise. + If not, then one operand must have one component, and the other + must be non-empty, and concatenation is distributive.<br> + + </table> + <p><font size=+1><b>Free Carets </b></font><br> + In most circumstances, <i>rc</i> will insert the <tt><font size=+1>^</font></tt> operator automatically + between words that are not separated by white space. Whenever + one of <tt><font size=+1>$ ' `</font></tt> follows a quoted or unquoted word or an unquoted + word follows a quoted word with no intervening blanks or tabs, + a <tt><font size=+1>^</font></tt> is inserted between the two. If an unquoted word + immediately follows a <tt><font size=+1>$</font></tt> and contains a character other than an + alphanumeric, underscore, or <tt><font size=+1>*</font></tt>, a <tt><font size=+1>^</font></tt> is inserted before the first + such character. Thus<br> + + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + <tt><font size=+1>cc −$flags $stem.c + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + </font></tt> + + </table> + is equivalent to<br> + + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + <tt><font size=+1>cc −^$flags $stem^.c<br> + </font></tt> + </table> + <p><font size=+1><b>I/O Redirections </b></font><br> + The sequence <tt><font size=+1>></font></tt><i>file</i> redirects the standard output file (file descriptor + 1, normally the terminal) to the named <i>file</i>; <tt><font size=+1>>></font></tt><i>file</i> appends standard + output to the file. The standard input file (file descriptor 0, + also normally the terminal) may be redirected from a file by the + sequence <tt><font size=+1><</font></tt><i>file</i>, or from an inline ‘here document’ by the + sequence <tt><font size=+1><<</font></tt><i>eof-marker</i>. The contents of a here document are lines + of text taken from the command input stream up to a line containing + nothing but the <i>eof-marker</i>, which may be either a quoted or unquoted + word. If <i>eof-marker</i> is unquoted, variable names of the form <tt><font size=+1>$</font></tt><i>word</i> + have their values substituted from <i>rc’s + </i>environment. If <tt><font size=+1>$</font></tt><i>word</i> is followed by a caret (<tt><font size=+1>^</font></tt>), the caret is + deleted. If <i>eof-marker</i> is quoted, no substitution occurs. + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + Redirections may be applied to a file-descriptor other than standard + input or output by qualifying the redirection operator with a + number in square brackets. For example, the diagnostic output + (file descriptor 2) may be redirected by writing <tt><font size=+1>cc junk.c >[2]junk</font></tt>. + + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + A file descriptor may be redirected to an already open descriptor + by writing <tt><font size=+1>>[</font></tt><i>fd0</i><tt><font size=+1>=</font></tt><i>fd1</i><tt><font size=+1>]</font></tt> or <tt><font size=+1><[</font></tt><i>fd0</i><tt><font size=+1>=</font></tt><i>fd1</i><tt><font size=+1>]</font></tt>. <i>Fd1</i> is a previously opened + file descriptor and <i>fd0</i> becomes a new copy (in the sense of <a href="../man3/dup.html"><i>dup</i>(3)</a>) + of it. A file descriptor may be closed by writing <tt><font size=+1>>[</font></tt><i>fd0</i><tt><font size=+1>=]</font></tt> or <tt><font size=+1><[</font></tt><i>fd0</i><tt><font size=+1>=]</font></tt>. + + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + Redirections are executed from left to right. Therefore, <tt><font size=+1>cc junk.c + >/dev/null >[2=1]</font></tt> and <tt><font size=+1>cc junk.c >[2=1] >/dev/null</font></tt> have different effects: + the first puts standard output in <tt><font size=+1>/dev/null</font></tt> and then puts diagnostic + output in the same place, where the second directs diagnostic + output to the + terminal and sends standard output to <tt><font size=+1>/dev/null</font></tt>.<br> + <p><font size=+1><b>Compound Commands </b></font><br> + A pair of commands separated by a pipe operator (<tt><font size=+1>|</font></tt>) is a command. + The standard output of the left command is sent through a pipe + to the standard input of the right command. The pipe operator + may be decorated to use different file descriptors. <tt><font size=+1>|[</font></tt><i>fd</i><tt><font size=+1>]</font></tt> connects + the output end of the pipe to file descriptor <i>fd</i> rather + than 1. <tt><font size=+1>|[</font></tt><i>fd0</i><tt><font size=+1>=</font></tt><i>fd1</i><tt><font size=+1>]</font></tt> connects output to <i>fd1</i> of the left command + and input to <i>fd0</i> of the right command. + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + A pair of commands separated by <tt><font size=+1>&&</font></tt> or <tt><font size=+1>||</font></tt> is a command. In either + case, the left command is executed and its exit status examined. + If the operator is <tt><font size=+1>&&</font></tt> the right command is executed if the left + command’s status is null. <tt><font size=+1>||</font></tt> causes the right command to be executed + if the left command’s status is non-null. + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + The exit status of a command may be inverted (non-null is changed + to null, null is changed to non-null) by preceding it with a <tt><font size=+1>!</font></tt>. + + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + The <tt><font size=+1>|</font></tt> operator has highest precedence, and is left-associative + (i.e. binds tighter to the left than the right). <tt><font size=+1>!</font></tt> has intermediate + precedence, and <tt><font size=+1>&&</font></tt> and <tt><font size=+1>||</font></tt> have the lowest precedence. + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + The unary <tt><font size=+1>@</font></tt> operator, with precedence equal to <tt><font size=+1>!</font></tt>, causes its operand + to be executed in a subshell. + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + Each of the following is a command.<br> + <tt><font size=+1>if (</font></tt> <i>list</i> <tt><font size=+1>)</font></tt> <i>command<br> + </i> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + A <i>list</i> is a sequence of commands, separated by <tt><font size=+1>&</font></tt>, <tt><font size=+1>;</font></tt>, or newline. + It is executed and if its exit status is null, the <i>command</i> is + executed.<br> + + </table> + <tt><font size=+1>if not</font></tt> <i>command<br> + </i> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + The immediately preceding command must have been <tt><font size=+1>if(</font></tt><i>list</i><tt><font size=+1>)</font></tt> <i>command</i>. + If its condition was non-zero, the <i>command</i> is executed.<br> + + </table> + <tt><font size=+1>for(</font></tt><i>name</i> <tt><font size=+1>in</font></tt> <i>arguments</i><tt><font size=+1>)</font></tt> <i>command<br> + </i><tt><font size=+1>for(</font></tt><i>name</i><tt><font size=+1>)</font></tt> <i>command<br> + </i> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + The <i>command</i> is executed once for each <i>argument</i> with that argument + assigned to <i>name</i>. If the argument list is omitted, <tt><font size=+1>$*</font></tt> is used.<br> + + </table> + <tt><font size=+1>while(</font></tt><i>list</i><tt><font size=+1>)</font></tt> <i>command<br> + </i> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + The <i>list</i> is executed repeatedly until its exit status is non-null. + Each time it returns null status, the <i>command</i> is executed. An + empty <i>list</i> is taken to give null status.<br> + + </table> + <tt><font size=+1>switch(</font></tt><i>argument</i><tt><font size=+1>){</font></tt><i>list</i><tt><font size=+1>}<br> + </font></tt> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + The <i>list</i> is searched for simple commands beginning with the word + <tt><font size=+1>case</font></tt>. (The search is only at the ‘top level’ of the <i>list</i>. That + is, <tt><font size=+1>cases</font></tt> in nested constructs are not found.) <i>Argument</i> is matched + against each word following <tt><font size=+1>case</font></tt> using the pattern-matching algorithm + described above, except that <tt><font size=+1>/</font></tt> and the + first characters of <tt><font size=+1>.</font></tt> and <tt><font size=+1>..</font></tt> need not be matched explicitly. When + a match is found, commands in the list are executed up to the + next following <tt><font size=+1>case</font></tt> command (at the top level) or the closing + brace.<br> + + </table> + <tt><font size=+1>{</font></tt><i>list</i><tt><font size=+1>}<br> + </font></tt> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + Braces serve to alter the grouping of commands implied by operator + priorities. The <i>body</i> is a sequence of commands separated by <tt><font size=+1>&</font></tt>, + <tt><font size=+1>;</font></tt>, or newline.<br> + + </table> + <tt><font size=+1>fn</font></tt> <i>name</i><tt><font size=+1>{</font></tt><i>list</i><tt><font size=+1>}<br> + fn</font></tt> <i>name<br> + </i> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + The first form defines a function with the given <i>name</i>. Subsequently, + whenever a command whose first argument is <i>name</i> is encountered, + the current value of the remainder of the command’s argument list + will be assigned to <tt><font size=+1>$*</font></tt>, after saving its current value, and <i>rc</i> + will execute the <i>list</i>. The second form removes + <i>name</i>’s function definition.<br> + + </table> + <tt><font size=+1>fn</font></tt> <i>note</i><tt><font size=+1>{</font></tt><i>list</i><tt><font size=+1>}<br> + fn</font></tt> <i>note<br> + </i> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + A function with a special name will be called when <i>rc</i> receives + a corresponding note; see <a href="../man3/notify.html"><i>notify</i>(3)</a>. The valid note names (and + corresponding notes) are <tt><font size=+1>sighup</font></tt> (<tt><font size=+1>hangup</font></tt>), <tt><font size=+1>sigint</font></tt> (<tt><font size=+1>interrupt</font></tt>), + <tt><font size=+1>sigalrm</font></tt> (<tt><font size=+1>alarm</font></tt>), and <tt><font size=+1>sigfpe</font></tt> (floating point trap). By default + <i>rc</i> exits on receiving any signal, except when + run interactively, in which case interrupts and quits normally + cause <i>rc</i> to stop whatever it’s doing and start reading a new command. + The second form causes <i>rc</i> to handle a signal in the default manner. + <i>Rc</i> recognizes an artificial note, <tt><font size=+1>sigexit</font></tt>, which occurs when <i>rc</i> + is about to finish executing. + + </table> + <i>name</i><tt><font size=+1>=</font></tt><i>argument command<br> + </i> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + Any command may be preceded by a sequence of assignments interspersed + with redirections. The assignments remain in effect until the + end of the command, unless the command is empty (i.e. the assignments + stand alone), in which case they are effective until rescinded + by later assignments. + + </table> + <p><font size=+1><b>Built-in Commands </b></font><br> + These commands are executed internally by <i>rc</i>, usually because + their execution changes or depends on <i>rc</i>’s internal state.<br> + <tt><font size=+1>.</font></tt> <i>file ...<br> + </i> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + Execute commands from <i>file</i>. <tt><font size=+1>$*</font></tt> is set for the duration to the + remainder of the argument list following <i>file</i>. <i>File</i> is searched + for using <tt><font size=+1>$path</font></tt>.<br> + + </table> + <tt><font size=+1>builtin</font></tt> <i>command ...<br> + </i> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + Execute <i>command</i> as usual except that any function named <i>command</i> + is ignored in favor of the built-in meaning.<br> + + </table> + <tt><font size=+1>cd [</font></tt><i>dir</i><tt><font size=+1>]<br> + </font></tt> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + Change the current directory to <i>dir</i>. The default argument is <tt><font size=+1>$home</font></tt>. + <i>dir</i> is searched for in each of the directories mentioned in <tt><font size=+1>$cdpath</font></tt>.<br> + + </table> + <tt><font size=+1>eval [</font></tt><i>arg ...</i><tt><font size=+1>]<br> + </font></tt> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + The arguments are concatenated separated by spaces into a single + string, read as input to <i>rc</i>, and executed.<br> + + </table> + <tt><font size=+1>exec [</font></tt><i>command ...</i><tt><font size=+1>]<br> + </font></tt> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + This instance of <i>rc</i> replaces itself with the given (non-built-in) + <i>command</i>.<br> + + </table> + <tt><font size=+1>flag</font></tt> <i>f</i> <tt><font size=+1>[+−]<br> + </font></tt> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + Either set (<tt><font size=+1>+</font></tt>), clear (<tt><font size=+1>−</font></tt>), or test (neither <tt><font size=+1>+</font></tt> nor <tt><font size=+1>−</font></tt>) the flag + <i>f</i>, where <i>f</i> is a single character, one of the command line flags + (see Invocation, below).<br> + + </table> + <tt><font size=+1>exit [</font></tt><i>status</i><tt><font size=+1>]<br> + </font></tt> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + Exit with the given exit status. If none is given, the current + value of <tt><font size=+1>$status</font></tt> is used.<br> + + </table> + <tt><font size=+1>rfork</font></tt> [<tt><font size=+1>nNeEsfFm</font></tt>]<br> + + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + Become a new process group using <tt><font size=+1>rfork(</font></tt><i>flags</i><tt><font size=+1>)</font></tt> where <i>flags</i> is composed + of the bitwise OR of the <tt><font size=+1>rfork</font></tt> flags specified by the option letters + (see <a href="../man2/fork.html"><i>fork</i>(2)</a>). If no <i>flags</i> are given, they default to <tt><font size=+1>ens</font></tt>. The + <i>flags</i> and their meanings are: <tt><font size=+1>n</font></tt> is <tt><font size=+1>RFNAMEG</font></tt>; <tt><font size=+1>N</font></tt> is <tt><font size=+1>RFCNAMEG</font></tt>; <tt><font size=+1>e</font></tt> is + <tt><font size=+1>RFENVG</font></tt>; <tt><font size=+1>E</font></tt> is <tt><font size=+1>RFCENVG</font></tt>; <tt><font size=+1>s</font></tt> is + <tt><font size=+1>RFNOTEG</font></tt>; <tt><font size=+1>f</font></tt> is <tt><font size=+1>RFFDG</font></tt>; <tt><font size=+1>F</font></tt> is <tt><font size=+1>RFCFDG</font></tt>; and <tt><font size=+1>m</font></tt> is <tt><font size=+1>RFNOMNT</font></tt>.<br> + + </table> + <tt><font size=+1>shift [</font></tt><i>n</i><tt><font size=+1>]<br> + </font></tt> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + Delete the first <i>n</i> (default 1) elements of <tt><font size=+1>$*</font></tt>.<br> + + </table> + <tt><font size=+1>wait [</font></tt><i>pid</i><tt><font size=+1>]<br> + </font></tt> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + Wait for the process with the given <i>pid</i> to exit. If no <i>pid</i> is + given, all outstanding processes are waited for.<br> + + </table> + <tt><font size=+1>whatis</font></tt> <i>name ...<br> + </i> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + Print the value of each <i>name</i> in a form suitable for input to <i>rc</i>. + The output is an assignment to any variable, the definition of + any function, a call to <tt><font size=+1>builtin</font></tt> for any built-in command, or the + completed pathname of any executable file.<br> + + </table> + <tt><font size=+1>~</font></tt> <i>subject pattern ...<br> + </i> + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + The <i>subject</i> is matched against each <i>pattern</i> in sequence. If it + matches any pattern, <tt><font size=+1>$status</font></tt> is set to zero. Otherwise, <tt><font size=+1>$status</font></tt> + is set to one. Patterns are the same as for file name matching, + except that <tt><font size=+1>/</font></tt> and the first character of <tt><font size=+1>.</font></tt> and <tt><font size=+1>..</font></tt> need not be + matched explicitly. The <i>patterns</i> are not subjected to + file name matching before the <tt><font size=+1>~</font></tt> command is executed, so they need + not be enclosed in quotation marks.<br> + + </table> + <p><font size=+1><b>Environment </b></font><br> + The <i>environment</i> is a list of strings made available to executing + binaries by the kernel. <i>Rc</i> creates an environment entry for each + variable whose value is non-empty, and for each function. The + string for a variable entry has the variable’s name followed by + <tt><font size=+1>=</font></tt> and its value. If the value has more than one component, + these are separated by SOH (001) characters. The string for a + function is just the <i>rc</i> input that defines the function. The name + of a function in the environment is the function name preceded + by <tt><font size=+1>fn#</font></tt>. + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + When <i>rc</i> starts executing it reads variable and function definitions + from its environment.<br> + <p><font size=+1><b>Special Variables </b></font><br> + The following variables are set or used by <i>rc</i>.<br> + <tt><font size=+1>$*</font></tt> Set to <i>rc</i>’s argument list during initialization. Whenever a + <tt><font size=+1>.</font></tt> command or a function is executed, the current value is saved + and <tt><font size=+1>$*</font></tt> receives the new argument list. The saved value is restored + on completion of the <tt><font size=+1>.</font></tt> or function.<br> + <tt><font size=+1>$apid</font></tt> Whenever a process is started asynchronously with <tt><font size=+1>&</font></tt>, <tt><font size=+1>$apid</font></tt> + is set to its process id.<br> + <tt><font size=+1>$home</font></tt> The default directory for <tt><font size=+1>cd</font></tt>.<br> + <tt><font size=+1>$ifs</font></tt> The input field separators used in backquote substitutions. + If <tt><font size=+1>$ifs</font></tt> is not set in <i>rc</i>’s environment, it is initialized to blank, + tab and newline.<br> + <tt><font size=+1>$path</font></tt> The search path used to find commands and input files for + the <tt><font size=+1>.</font></tt> command. If not set in the environment, it is initialized + by parsing the <tt><font size=+1>$PATH</font></tt> variable (as in <a href="../man1/sh.html"><i>sh</i>(1)</a>) or by <tt><font size=+1>path=(. /bin)</font></tt>. + The variables <tt><font size=+1>$path</font></tt> and <tt><font size=+1>$PATH</font></tt> are maintained together: changes + to one will be reflected in the other. + <tt><font size=+1>$pid</font></tt> Set during initialization to <i>rc</i>’s process id.<br> + <tt><font size=+1>$prompt</font></tt> When <i>rc</i> is run interactively, the first component of <tt><font size=+1>$prompt</font></tt> + is printed before reading each command. The second component is + printed whenever a newline is typed and more lines are required + to complete the command. If not set in the environment, it is + initialized by <tt><font size=+1>prompt=('% ' ' ')</font></tt>. + <tt><font size=+1>$status</font></tt> Set to the wait message of the last-executed program. (unless + started with <tt><font size=+1>&). !</font></tt> and <tt><font size=+1>~</font></tt> also change <tt><font size=+1>$status</font></tt>. Its value is used + to control execution in <tt><font size=+1>&&</font></tt>, <tt><font size=+1>||</font></tt>, <tt><font size=+1>if</font></tt> and <tt><font size=+1>while</font></tt> commands. When <i>rc</i> exits + at end-of-file of its input or on executing an <tt><font size=+1>exit</font></tt> command with + no argument, <tt><font size=+1>$status</font></tt> is its + + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + exit status.<br> + + </table> + + </table> + <p><font size=+1><b>Invocation </b></font><br> + If <i>rc</i> is started with no arguments it reads commands from standard + input. Otherwise its first non-flag argument is the name of a + file from which to read commands (but see <tt><font size=+1>−c</font></tt> below). Subsequent + arguments become the initial value of <tt><font size=+1>$*</font></tt>. <i>Rc</i> accepts the following + command-line flags.<br> + <tt><font size=+1>−c</font></tt> <i>string</i> Commands are read from <i>string</i>.<br> + <tt><font size=+1>−s</font></tt> Print out exit status after any command where the status is + non-null.<br> + <tt><font size=+1>−e</font></tt> Exit if <tt><font size=+1>$status</font></tt> is non-null after executing a simple command.<br> + <tt><font size=+1>−i</font></tt> If <tt><font size=+1>−i</font></tt> is present, or <i>rc</i> is given no arguments and its standard + input is a terminal, it runs interactively. Commands are prompted + for using <tt><font size=+1>$prompt</font></tt>.<br> + <tt><font size=+1>−I</font></tt> Makes sure <i>rc</i> is not run interactively.<br> + <tt><font size=+1>−l</font></tt> If <tt><font size=+1>−l</font></tt> is given or the first character of argument zero is <tt><font size=+1>−</font></tt>, + <i>rc</i> reads commands from <tt><font size=+1>$home/lib/profile</font></tt>, if it exists, before + reading its normal input.<br> + <tt><font size=+1>−p</font></tt> A no-op.<br> + <tt><font size=+1>−d</font></tt> A no-op.<br> + <tt><font size=+1>−v</font></tt> Echo input on file descriptor 2 as it is read.<br> + <tt><font size=+1>−x</font></tt> Print each simple command before executing it.<br> + <tt><font size=+1>−r</font></tt> Print debugging information (internal form of commands as they + are executed).<br> + +</table> +<p><font size=+1><b>SOURCE </b></font><br> + +<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + <tt><font size=+1>/usr/local/plan9/src/cmd/rc<br> + </font></tt> +</table> +<p><font size=+1><b>SEE ALSO </b></font><br> + +<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + Tom Duff, “Rc – The Plan 9 Shell”.<br> + +</table> +<p><font size=+1><b>BUGS </b></font><br> + +<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + There should be a way to match patterns against whole lists rather + than just single strings. + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + Using <tt><font size=+1>~</font></tt> to check the value of <tt><font size=+1>$status</font></tt> changes <tt><font size=+1>$status</font></tt>. + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + Functions that use here documents don’t work. + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + Free carets don’t get inserted next to keywords. + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + The <tt><font size=+1><{</font></tt><i>command</i><tt><font size=+1>}</font></tt> syntax depends on the underlying operating system + providing a file descriptor device tree at <tt><font size=+1>/dev/fd</font></tt>. + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + By default, FreeBSD 5 does not provide file descriptors greater + than 2 in <tt><font size=+1>/dev/fd</font></tt>. To fix this, add<br> + + <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + <tt><font size=+1>/fdescfs /dev/fd fdescfs rw 0 0<br> + + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + </font></tt> + + </table> + to <tt><font size=+1>/etc/fstab</font></tt>, and then <tt><font size=+1>mount /dev/fd</font></tt>. (Adding the line to <tt><font size=+1>fstab</font></tt> + ensures causes FreeBSD to mount the file system automatically + at boot time.)<br> + +</table> + +<td width=20> +<tr height=20><td> +</table> +<!-- TRAILER --> +<table border=0 cellpadding=0 cellspacing=0 width=100%> +<tr height=15><td width=10><td><td width=10> +<tr><td><td> +<center> +<a href="../../"><img src="../../dist/spaceglenda100.png" alt="Space Glenda" border=1></a> +</center> +</table> +<!-- TRAILER --> +</body></html> |