#include

#include

std::vector parseCommandLine$($const std::string& aCommandLine$)\{$

std::vector tokens;

size$\_$t start $=0$;

while $($start $<$ aCommandLine.size$())\{$

size$\_$t end $=$ start;

while $($end $<$ aCommandLine.size$()$ &&

aCommandLine$[$end$]!=\text{'}\text{'}$ &&

aCommandLine$[$end$]!=\text{'}<\text{'}$ &&

aCommandLine$[$end$]!=\text{'}>\text{'}$ &&

aCommandLine$[$end$]!=\text{'}|\text{'})\{$

$++$end;

$\}$

$//$ Break out of the loop when a special character is encountered

if $($end $<$ aCommandLine.size$()$ &&

$($aCommandLine$[$end$]==\text{'}<\text{'}||$ aCommandLine$[$end$]==\text{'}>\text{'}||$ aCommandLine$[$end$]==\text{'}|\text{'}))\{$

std::string token $=$ aCommandLine.substr$($start$,$ end $-$ start$)$;

if $(!$token.empty$()$ && $($token$.$back$()==\text{'}<\text{'}||$ token.back$()==\text{'}>\text{'}))\{$

tokens.push$\_$back$($token$.$substr$(0,$ token.size$()-1))$;

tokens.push$\_$back$($std::string$(1,$ token.back$()))$;

$\}$ else if $($token $=="<<"$ && start $==0)\{$

tokens.push$\_$back$($token$)$;

$\}$ else if $($token $=="|")\{$

tokens.push$\_$back$($token$)$;

$\}$ else if $(!$token.empty$())\{$

tokens.push$\_$back$($token$)$;

$\}$

tokens.push$\_$back$($std::string$(1,$ aCommandLine$[$end$]))$;

$++$end; $//$ Move past the special character

$\}$ else $\{$

std::string token $=$ aCommandLine.substr$($start$,$ end $-$ start$)$;

if $(!$token.empty$()$ && $($token$.$back$()==\text{'}<\text{'}||$ token.back$()==\text{'}>\text{'}))\{$

tokens.push$\_$back$($token$.$substr$(0,$ token.size$()-1))$;

tokens.push$\_$back$($std::string$(1,$ token.back$()))$;

$\}$ else if $($token $=="<<"$ && start $==0)\{$

tokens.push$\_$back$($token$)$;

$\}$ else if $($token $=="|")\{$

tokens.push$\_$back$($token$)$;

$\}$ else if $(!$token.empty$())\{$

tokens.push$\_$back$($token$)$;

$\}$

$\}$

while $($end $<$ aCommandLine.size$()$ && aCommandLine$[$end$]==\text{'}\text{'})\{$

$++$end;

$\}$

start $=$ end;

$\}$

return tokens;

$\}$

int main$()\{$

std::string commandLine $=$ "grep x $<$ myfile.textbfin $>$ myfile.out";

std::vector result $=$ parseCommandLine$($commandLine$)$;

for $($size$\_$t i $=0$; i $<$ result.size$()$; $++$i$)\{$

std::cout $<<$ "Token $"<<$ i $+1<<"$: $"<<$ result$[$i$]<<$ std::endl;

$\}$

return $0$;

$\}$