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| <tr><td width=20><td><b>9P-CMDBUF(3)</b><td align=right><b>9P-CMDBUF(3)</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> |
| |
| Cmdbuf, parsecmd, respondcmderror, lookupcmd – control message |
| parsing<br> |
| |
| </table> |
| <p><font size=+1><b>SYNOPSIS </b></font><br> |
| |
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| |
| <tt><font size=+1>#include <u.h><br> |
| #include <libc.h><br> |
| #include <fcall.h><br> |
| #include <thread.h><br> |
| #include <9p.h><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| typedef struct Cmdbuf<br> |
| {<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| char *buf;<br> |
| char **f;<br> |
| int nf;<br> |
| |
| </table> |
| } Cmdbuf;<br> |
| typedef struct Cmdtab<br> |
| {<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| int index;<br> |
| char *cmd;<br> |
| int narg;<br> |
| |
| </table> |
| };<br> |
| Cmdbuf *parsecmd(char *p, int n)<br> |
| Cmdtab *lookupcmd(Cmdbuf *cb, Cmdtab *tab, int ntab)<br> |
| void respondcmderror(Req *r, Cmdbuf *cb, char *fmt, ...)<br> |
| </font></tt> |
| </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> |
| |
| These data structures and functions provide parsing of textual |
| control messages. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| <i>Parsecmd</i> treats the <i>n</i> bytes at <i>p</i> (which need not be NUL-terminated) |
| as a UTF string and splits it using <i>tokenize</i> (see <a href="../man3/getfields.html"><i>getfields</i>(3)</a>). |
| It returns a <tt><font size=+1>Cmdbuf</font></tt> structure holding pointers to each field in |
| the message. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| <i>Lookupcmd</i> walks through the array <i>ctab</i>, which has <i>ntab</i> entries, |
| looking for the first <tt><font size=+1>Cmdtab</font></tt> that matches the parsed command. |
| (If the parsed command is empty, <i>lookupcmd</i> returns nil immediately.) |
| A <tt><font size=+1>Cmdtab</font></tt> matches the command if <i>cmd</i> is equal to <i>cb</i><tt><font size=+1>−></font></tt><i>f</i><tt><font size=+1>[0]</font></tt> or if |
| <i>cmd</i> is <tt><font size=+1>*</font></tt>. Once a matching <tt><font size=+1>Cmdtab</font></tt> has been |
| found, if <i>narg</i> is not zero, then the parsed command must have |
| exactly <i>narg</i> fields (including the command string itself). If |
| the command has the wrong number of arguments, <i>lookupcmd</i> returns |
| nil. Otherwise, it returns a pointer to the <tt><font size=+1>Cmdtab</font></tt> entry. If <i>lookupcmd</i> |
| does not find a matching command at all, it returns |
| nil. Whenever <i>lookupcmd</i> returns nil, it sets the system error |
| string. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| <i>Respondcmderror</i> resoponds to request <i>r</i> with an error of the form |
| ‘<i>fmt</i>: <i>cmd</i>,’ where <i>fmt</i> is the formatted string and <i>cmd</i> is a reconstruction |
| of the parsed command. Fmt is often simply <tt><font size=+1>%r .<br> |
| </font></tt> |
| </table> |
| <p><font size=+1><b>EXAMPLES </b></font><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| This interface is not used in any distributed 9P servers. It was |
| lifted from the Plan 9 kernel. Almost any Plan 9 kernel driver |
| (<tt><font size=+1>/sys/src/9/*/dev*.c</font></tt> on Plan 9) is a good example.<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/lib9p/parse.c<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> |
| |
| <a href="../man3/9p.html"><i>9p</i>(3)</a><br> |
| |
| </table> |
| |
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