Script returning unwanted result

chy_vak · 11-23-2016, 08:33 AM

Hi linuxuestions,

Here's what I currently have (top bash window) and the result the syntax returns (bottom bash window), image link below.

When a name does not exist, such as "xyz" it returns the appropriate response.

When a name does exist, such as "joel" it echos an unwanted response before providing the correct response..

What am I missing?
Please advise,
Thanks in advance!

Here's the image

szboardstretcher · 11-23-2016, 08:39 AM

Because the grep line needs to go between the if blocks.

ie:

Code:

if 
read blah
fi

grep

if some test
echo failed
fi

chy_vak · 11-23-2016, 08:52 AM

Here's the updated syntax http://imgur.com/a/AcKFf

The issue continues to persist, except now when a name doesnt exist, it doesnt echo "$name not in directory"

szboardstretcher · 11-23-2016, 09:00 AM

Because your exit code test is wrong.

Code:

## This line is saying "if the last exit code is NOT 'a selection was not found'" then print 'not found' ...
## which is the OPPOSITE of what you are saying you want
if [ $? -ne 1 ]; then
 echo "Not found"
fi

https://www.gnu.org/software/grep/ma...it-Status.html

michaelk · 11-23-2016, 09:16 AM

To elaborate on szboardstretcher post... From the grep man page

Quote:

EXIT STATUS
The exit status is 0 if selected lines are found, and 1 if not found.

chy_vak · 11-23-2016, 09:18 AM

I got the script to work with this
http://imgur.com/a/86vwp

For some reason, however, the tutorial Im using is telling me that "phone4 is not returning the expected result"

Odd, I cant continue the tutorial without passing this part.

szboardstretcher · 11-23-2016, 09:22 AM

Hit up their community or help section to see what it is that they want. Can't help here without specifics. Good luck!

fyi: I made a oneliner so you can see the different grep exit statuses:

Code:

echo asdf > testfile_abc; grep asdf testfile_abc; echo "Found text, exit code: $?"; grep qwerf testfile_abc; echo "Did not find text, exit code: $?"

grail · 11-23-2016, 10:15 AM

In the future, please use the [code][/code] tags instead of screen grabs and links to other pages.

Interestingly, your first solution could have worked with a small tweak:

Code:

name=$1

if [[ -z "$name" ]]
then
  echo -n "Enter a name to search for: "
  read name  # if user presses enter and name is blank this could cause problems
fi

output=$(grep -i "$name" phonebook)

if [[ -z "$output" ]]
then
  echo "Name $name not in directory"
else
  echo "$output"
fi

By moving the 'output' variable down, we negate the fact that the user might not enter a name at the command line. Either time the 'name' variable is blank will cause grep to wait for more input.

You could also place the request for a name in a loop until the user enters something. You may also wish to consider what happens if the user puts unusual characters in for a name.

szboardstretcher · 11-23-2016, 10:32 AM

Thanks for typing that out grail. I saw your post with the actual [code] tags, before you fixed it

I suppose if I were to continue making it as small as possible, while avoiding null inputs, I would do it this way:

Code:

name=$1

while [ -z "$name" ]; do
 read -p "Enter a name to search for: " name
done

 grep -i "$name" phonebook > /dev/null && echo "$name found" || echo "$name not found"

grail · 11-23-2016, 12:32 PM

Whilst I follow your logic szboardstretcher, the OP wants the output from the phonebook, not just the name entered by the user

szboardstretcher · 11-23-2016, 12:37 PM

Ahh. Missed that. I blame it on the pictures

I guess removing the redirection and the && would do that.

Code:

name=$1
while [ -z "$name" ]; do
 read -p "Enter a name to search for: " name
done
 grep -i "$name" phonebook || echo "$name not found"