Rc \(em A Shell for Plan 9 and UNIX g Simple commands s Quotation s Comments and continuation s I/O Redirection s Pipelines s Filename patterns s Variables s Arguments s Concatenation s Free carets s Command substitution s Pipeline branching s Exit status s Flow of control s Command grouping s Subshells s Conditional execution \(em \f(CW&&\fP and \f(CW||\fP x Control flow \(em \f(CWfor\fP t Conditional execution \(em \f(CWif\fP t Control flow \(em \f(CWwhile\fP t Control flow \(em \f(CWswitch\fP t Functions s Command execution s Built-in commands s Special variables s Advanced I/O Redirection s Here documents s Signals s Environment s Local Variables s Invocation s grammar s Bourne shell current directory s debugging s diagnostic output s eof marker s file descriptor s filename s interactive mode s parent process s process id s initialization procedure s parser s standard input s standard output s unquoted word s variable substitution s white space s # S #e S $# S $$ S $cdpath S $home/.rcrc S & S && S * matches p . command p /bin S /env S /sys/lib/rcmain S /usr/lib/rcmain S ; S < S << S > S ? matches p @ operator p [ ] S \e S ^ S cd S else S for( S if( S rcmain S shift S while( S | characters p meta-characters s || S . [-i] \fIfile s builtin S eval S exec S exit S finit S flag S mount S umask S unmount S wait S whatis S fn S ~ S $* S $apid S $cflag S $home S $ifs S $path S $pid S $prompt S $status S sighup S sigint S sigquit S sigterm S sigexit S CW -c S TP -e S TP -i S TP -l S TP -p S TP -v S TP -x S TP -d S TP -r S fork S Plan 9 command interpreter g ~not wait ~and wait ~will wait yacc C ~to exit