CODEWITHSUNDEEP
bashshell
user3466773
user3466773

Reputation: 186

Find longest and shortest strings in stdin

This program is intended to read a file from stdin and return the longest and shortest lines. Right now it's in an infinite loop.Could someone tell me what I'm doing wrong?

Update: So after reading more about what read does, it's actually right (yay me) but I want to set the delimiter to a newline character while currently the read command is taking a string at every whitespace character. Does anyone know what I can do?

read T
short=""
long=""
for i in $T; do
   if [[ $short = "" ]]; then
       short=$i
   elif [[ ${#i} -lt ${#short} ]]; then
      short=$i
   elif [[ ${#i} -gt ${#long} ]];then
      long=$i
   fi
done
echo $short
echo $long

Upvotes: 0

Views: 255

Answers (1)

jvdm
jvdm

Reputation: 876

It can't possibly reach an infinite loop, since you are looping over a necessarily finite variable ($T).

I'm going to assume that your script is "hanging" and assume one of the possible reasons (to provide you one possible solution to your classroom problem): that the script is sleeping waiting for data from stdin and no data is being sent to him.

Here's what you could do:

read short
long=$short
while read line; do
    if [[ ${#line} -lt ${#short} ]]; then
        short=$line
    fi
    if [[ ${#line} -gt ${#long} ]]; then
        long=$line
    fi
done
echo $short
echo $long

Notice that I've first initialized the short and long with the first line of input, or empty string on stdin's EOF. Then I attempt to read more lines in a while loop to then check for conditions to update short and long; it is important to not exclude the line size checks if one of them applies (like you didn't in your script using elifs).

Upvotes: 1

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