consider the following incomplete c program that receives multiple lines from stdin, sort them alphabetically, and print them all out in the sorted order. Complete the program so that it allows the user to enter an optional command$-$line argument $"-$i$"$ when running the program to ignore the case when sorting the input lines. The default behavior should sort in a case$-$sensitive manner $```$

#include

#include

#include

#define MAX$\_$LINES $5000$

#define MAX$\_$LEN $1000$

char$*$ lineptr$$$\backslash$lbrack$$MAX$\_$LINES$$$\backslash$rbrack$$;

int read$\_$lines$($void$)\{$

char line$$$\backslash$lbrack$$MAX$\_$LEN$$$\backslash$rbrack$$;

int nline $=0$;$//$# of lines

while$($fgets$($line$,$MAX$\_$LEN, stdin$))\{$

int len $=$ strlen$($line$)$;

if$($line$$$\backslash$lbrack$$len$-1$$$$\backslash$rbrack$$ $==\text{'}\backslash$

n$\text{'})\{$

line$$$\backslash$lbrack$$len$-1$$$$\backslash$rbrack$$ $=\text{'}\backslash$

$0\text{'}$;

len$--$;

$\}$

lineptr$$$\backslash$lbrack$$nline$$$\backslash$rbrack$$ $=($

$)$ malloc$(($len $+1)*$sizeof$($char$))$;

if$($lineptr$$$\backslash$lbrack$$nline$$$\backslash$rbrack$$ $==$

$)//$heap is full, cannot allocate memory!

return $-1$;

$($lineptr$\backslash$$$\backslash$$$\backslash$lbrack$\backslash$$$\backslash$$nline$++\backslash$$$\backslash$$ rbrack$\backslash$$$\backslash$$$,$ line$)$;$//$a

lternative: lineptr$$$\backslash$lbrack$$nline$++$$$$\backslash$rbrack$$

$=$ strdup$($line$)$;

$\}$

$\}$

return nline;

void write$\_$lines$($int len$)\{$

for$($int i $=0$; i $$ len;i$++)$

printf$("\%$s

$",$ lineptr$$$\backslash$lbrack$$i$$$\backslash$rbr

ack$$$)$;

$\}$

$``````$

$($lineptr$$$\backslash$lbrack$$nline$++$$$$\backslash$rbrack$$$,$ line$)$;$//$a

lternative: lineptr$$$\backslash$lbrack$$nline$++$$$$\backslash$rbrack$$

$=$ strdup$($line$)$;

$\}$

return nline;

$\}$

void write$\_$lines$($int len$)\{$

for$($int i $=0$; i $$ len;i$++)$

ack$$$)$;

printf$("\%$s

$",$ lineptr$$$\backslash$lbrack$$i$$$\backslash$rbr

$\}$

int compare$\_$strings$($const void$*$ first, const voi

d$*$ second$)\{$

$//$returns a negative int if $*$first $<mtext></mtext><mi>*</mi>$second

$//$returns a positive int if $*$first $>*$second

$//$returns $0$ otherwise!

const char$**$ first$\_$string$\_$pointer $=($const c

har$**)$first;

const char$**$ second$\_$string$\_$pointer $=($const

char$**)$second;

return strcmp$(*$first$\_$string$\_$pointer, $*$second

$\_$string$\_$pointer$)$;

$\}$

int compare$\_$strings$\_$ignore$\_$case$($const void$*$ firs

t$,$ const void$*$ second$)\{$

$//$ignores case

const char$**$ first$\_$string$\_$pointer $=($const cha

r$**)$first;

const char$**$ second$\_$string$\_$pointer $=($const

char$**)$second;

return strcasecmp$(*$first$\_$string$\_$pointer, $*$seco

nd$\_$string$\_$pointer$)$;

$\}$

int main$($int arqc,

argv$$$[]$$$$)\{$

int number$\_$of$\_$lines, case$\_$sensitive $=1$;

if$($

$>1)$

case$\_$sensitive $=($strcmp$($argv$$$\backslash$lbrack$$

$``````$

argv$$$[]$$$$)\{$

int number$\_$of$\_$lines, case$\_$sensitive $=1$;

ifl

$>1)$

$```$

case$\_$sensitive $=($strcmp$($argv$$$\backslash$lbrack$$

$$$\backslash$rbrack$$$,"-$i$")==0)?0$: $1$;

if$(($number$\_$of$\_$lines $=$ read$\_$lines$())<mtext></mtext><mn>0</mn><mi>)</mi><mi>\{</mi>$

printf$("$Error: cannot store input stream

in the memory!

$")$;

$\}$

return $1$;$//$error code for low memory

s$)$;

printf$("$# of lines: $\%$d$.$

$",$ number$\_$of$\_$line

qsort$($lineptr$,($size$\_$t$)$number$\_$of$\_$lines, size

of$($char$*),$

case sensitive$?$

:

$)$;

write$\_$lines

$)$;

for$($int i $=0$; i $$ number$\_$of$\_$lines;i$++)$

$($lineptr$$$\backslash$lbrack$$i$$$\backslash$rbrack$$$)$;$//$deallocate me

mory

$\}$