$/*$ Given a filename, figure out if it's a directory or text file.

$*$ If text file $($base case$),$ scan it$,$ incrementing word counts as you go$.$

$*$ If directory, recurse.

$*$ Otherwise, ignore

$*/$

void process$\_$file$($char $*$name$,$ amap$\_$t $*$m$)\{$

$/********$ YOUR CODE HERE $************/$

$/*$ What kind of file is it$?$

$*$ Hint: use check$\_$type$()$

$*/$

$/*$ if FTYPE$\_$REG: use count$\_$words$().$ Note arg types expected by it$.$

$*$ Hint: fdopen$().$

$*$ Hint: account for what check$\_$type$()$ does with a regular file.

$*/$

$/*$ if FTYPE$\_$DIR: use opendir and readdir t$0$ get entries,

$*$ and recursively process each.

$/*$ if anything else, ignore it$.*/$

$\}$

$/*$

$*$ Driver for the scanning process.

$*$ Process the files under the given name $($process$\_$file$),$ recursively,

$*$ incrementing count in the map for each word found in a text file.

$*$ Then write the contents of the map to each reducer pipe, according to

$*$ the first letter of the word $($using the writepipes map$).$

$*$ Then close all the write ends of the reducer pipes.

$*$ Parameters:

$*$ nprocs $=$ # of scanners$/$reducers$/$pipes

$*$ map $=$ sorted map of words to counts

$*$ startname $=$ file$/$dir to process

$*$ reducepipes $=$ array of pipe fds to get counts to reducers

$*$ THIS FUNCTION DOES NOT RETURN

$*/$

void scanner$($int nprocs, amap$\_$t $*$map$,$ char $*$startname$,$ pipe$\_$t $*$reducepipes$)\{$

$/*************$ YOUR CODE HERE $*********************/$

$/*$ first call process$\_$file$()$ on the startname. $*/$

$/*$ Then write each $($string$,$count$)$ pair in the map to the appropriate

$*$ reducer.

$*$ Hint: use amap$\_$getnext$().$

$*$ Hint: whichpipe maps character #s $(\text{'}$a$\text{'}=0,\text{'}$b$\text{'}=1,$ etc.$)$ to reduce pipe #s$.$

$*$ the first letter of the word $($using the writepipes map$).$

$*$ Parameters:

$*$ nprocs $=$ # of scanners$/$reducers$/$pipes

$*$ map $=$ sorted map of words to counts

$*$ startname $=$ file$/$dir to process

$*$ reducepipes $=$ array of pipe fds to get counts to reducers

$*$ THIS FUNCTION DOES NOT RETURN

$*/$

void scanner$($int nprocs, amap$\_$t $*$map$,$ char $*$startname$,$ pipe$\_$t $*$reducepipes$)\{$

$/*************$ YOUR CODE HERE $*********************/$

$/*$ first call process$\_$file$()$ on the startname. $*/$

$/*$ Then write each $($string$,$count$)$ pair in the map to the appropriate

$*$ reducer.

$*$ Hint: use amap$\_$getnext$().$

$*$ Hint: whichpipe maps character #s $(\text{'}$a$\text{'}=0,\text{'}$b$\text{'}=1,$ etc.$)$ to reduce pipe #s$.$

$*/$

$/*$ Then close my write end of each reduce pipe. $*/$

$/*$ Then close my write end of each reduce pipe. $*/$

exit$(0)$; $//$ all done!

$\}$