Shell Programming and Scripting

1, 3, 4, 6, 10, 30, 48, 49, 50, 51......89999, 90000

nums='1, 3, 4, 6, 10, 30, 48, 49, 50, 51, 89999, 90000'

num=39

echo $nums, $num | tr , '\n' | sort -n | grep -C1 $num | xargs |             
  read a b c d; if ((b-a <= c-b));then echo $a; else echo $c; fi

 awk -v VAL=5 -v RS="," '{
        D=(VAL - $1) * (VAL - $1);
        if((!SET) || (D < DIFF))
        {
                DIFF=D;
                X=$1;
                SET=1;
        }
}

END {   printf("Closest was %s\n", X);  }' < data

# cat /tmp/23.sh
#!/usr/bin/bash
>/tmp/results
IFS=" ,"
OFS="\n"
v=$1
for i in `cat /tmp/90`
do
for x in {0..100}
do
t=`echo "$v-$x"|bc`
if [[ $t = $i ]]
then
echo $i >> /tmp/results
fi
done
done
echo "`tail -1 /tmp/results`"

while read -d "," V
do
        ...
done < filename

 awk -v VAL=39 -v RS="," '{
        D=(VAL - $1) * (VAL - $1);
        if((VAL<=$1)&&(((!SET) || (D < DIFF))))
        {
                DIFF=D;
                X=$1;
                SET=1;
        }
}

END {   if(!SET)        print "No greater value found";
        else            printf("Closest was %s\n", X);  }' < data

awk -v VAL=39 -v RS="," '{
        D=(VAL - $1) * (VAL - $1);

        if((VAL<=$1)&&(((!SETA) || (D < DIFFA))))
        {
                DIFFA=D;
                XA=$1;
                SETA=1;
        }

        if((VAL>=$1)&&(((!SETB) || (D < DIFFB))))
        {
                DIFFB=D;
                XB=$1;
                SETB=1;
        }
}

END {   if(!SETA)       print "No greater bound";
        else            printf("Closest greater bound was %s\n", XA);

        if(!SETB)       print "No lesser bound";
        else            printf("Closest lesser bound was %s\n", XB);   }' < data