use this template code

#include #include #include #include #include $//!!!$ DO NOT CHNAGE BUFSIZE #define BUFSIZE $10/*$ size of chunk to be read $*/$ #define PERM $0644/*$ file permission for new file $*/$ int concatFiles$($const char$*$ name$1,$ const char$*$ name$2,$ const char$*$ name$3)\{$ int infile$1=-1,$ infile$2=-1,$ outfile$=-1$; ssize$\_$t nread, nwrite; char buffer$[$BUFSIZE$]$; if$(($ infile$1=$ open$($name$1,\_\_\_\_\_\_\_\_\_\_\_))==-1)$ return $(-1)$; if$(($ infile$2=$ open$($name$2,\_\_\_\_\_\_\_\_\_\_\_))==-1)$ return $(-1)$; if$(($ outfile $=$ open$($name$3,\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_,$ PERM$))==-1)$ return $(-1)$; $////////$ Fill out this part!! $--$ main loop$($s$)////////$ close$($infile$1)$; close$($infile$1)$; close $($outfile$)$; return $1$; $\}$ int main$($int argc, char$**$argv$)\{$ if$($argc$!=4)\{$ printf$("$Usage: concatFiles file$1$ file$2$ file$3$

$")$; exit$(-1)$; $\}$ int retcode$=-1$; retcode $=$ concatFiles$($argv$[1],$ argv$[2],$ argv$[3])$; $\}$

to answer this question below

$1.(50$ points$)$ Complete a function "concatFiles$($const char$*$ name$1,$ const char$*$ name$2,$ const char$*$ name$3)"$ in the attached program template "prog.c$"$ After its completion, name$3$ file will have contents obtained by concatenating the contents of namel file and name$2$ file. For example, if name$1$ file contains the following $9$ characters:

ABCDMHJWP

And, if name$2$ file contains the following $6$ characters: TUVXYZ

Then, after its execution the name$2$ file will contain $15$ characters:

ABCDMHJWPTUVXYZ

You can only make use of the following system calls in the function implementation:

a$.$ open$()$

b$.$ read$()$

c$.$ Iseek$()$

d$.$ write$()$

e$.$close$()$

You have to complete the function definition in the attached "prog.c$"$ file which includes main$()$ calling dupFile$("$datal$.$txt$",$ "data$2.$txt$").$ "datal.txt$"$ file is also attached. Your function should use the buffer size of $10$ bytes in reading and writing. Please take the following requirements into account when you create the function definition:

$-$ namer file and name$2$ f$$le should be existent when the function is called. Otherwise, your program should exit without doing anything.

$-$ Name$3$ file should not be existent when you call the function. It needs to be created as an empty file and the contents need to be filled up$.$ If name$3$ file already exists, your program should exit without doing anything.