Justin's questions

I was in the middle of upgrading to Ubuntu 16.04 and the upgrade froze about halfway through, freezing my entire computer. I had to manually reboot it, and when I did so, it loaded into the terminal and has remained there. I have full access and ability within the terminal, but I can't seem to log back into the GUI/Desktop environment. I honestly have no idea what to do at this point, and I'd really rather not wipe my computer clean and re-install Ubuntu.

Any comments/suggestions are highly welcome!

I'm interested in figuring out a way to delete an entire line in a text file that contains a particular string. This will be for a text file that operates like a phone book containing names, address, phone numbers, etc

[Ex]

John Smith, 123 Fake St, 555-555-555

I want to know how I can search for a particular name and remove the entire line that contains it. So for the example above, I would search for "John" or "Smith" or "John Smith" and remove the entire line that contains those words.

Would I used grep, or sed for this? I want it to make a permanent change to the file

I want to use grep in an If statement to search for a first-name and last-name within a text file. I can't seem to make it work on my own.

if [[ grep -E "$first|$last" Datafile.txt ]]
    then
            echo "This name already exists"
    else
            echo "This name doesn't exist yet"
    fi

Any suggestions??

I'm trying to write a script that will look for a certain .txt file saved to my desktop. I want the script to be able to check if this file exists and then check to see if it is readable and writable.

Any hints?

I would like to use the grep command to print a line number for the string I'm searching for. However, when I used the command grep -n it prints the line number with a colon : next to it. Is there any way I can use the same grep -n command to print a line number with it being followed by the : colon?

$ grep -n 'Captain' sometextfile.txt
3: Captain America

I would like it to instead print,

3 Captain America

(without the ':' )

Any suggestions??

I'm interested in storing an address in a variable called "address" using the read command in a Bash script. However, I'm having an issue with the multiple words an address usually has. Is there a way to store several words into one variable instead of just one? For example:

echo "Please enter your address"
[user puts in 123 Fake street]
read address
echo $address
[output is just 123]

I'm interested in sorting a text file that has entries with the First name and Last name in that order

[Ex]

John Doe

I'm interested in sorting the list by LAST name only. Is this a job for sed or awk? Can I modify the sortcommand to sort by the second word or LAST name only?

I'm interesting in directing the output from two commands to a variable. I don't want the output to be displayed on the screen, but instead assigned to a variable within my script so that I can use it again.

what I am doing is getting the file size from a directory using the commands seen below:

ls -l /var/spool | wc -c

This command gets me the file size in bytes and displays the output as an integer. I am interested in getting this integer assigned to a variable of my liking so that I can compare it against another variable later

This doesn't seem to work:

size = ls -l /var/spool | wc -c

Would redirection work?

Like this....

ls -l /var/spool | wc -c > size

Either way I want this numeric output to be assigned to a variable and not displayed on the screen.

Any suggestions are very welcomed!

What is the point of the "null" operator in a BASH script? I understand that it is used as a placeholder following an if command when you have nothing to say, but need a command to allow the program to run properly. But what is the overall use for it? When would you use it? When does it make sense to use it?

I can't seem to find any clear information on what the .bashrc file is and what it does exactly.

Thanks for all the help so far. It seems that this script does everything from coloring, completion, aliases and shell history, etc. Is there anything that does not seem useful?

I have a text file with several names that are arranged with the First name first, and the Last name second. How can I use Sed to reverse this order of names so that the Last name is first, and the First name is last?

For example I have lines like below

Steve Blenheim:238-923-7366:95 Latham Lane, Easton, PA 83755:11/12/56:20300
Betty Boop:245-836-8357:635 Cutesy Lane, Hollywood, CA 91464:6/23/23:14500
Igor Chevsky:385-375-8395:3567 Populus Place, Caldwell, NJ 23875:6/18/68:23400

I would like them to look like

Blenheim Steve:238-923-7366:95 Latham Lane, Easton, PA 83755:11/12/56:20300
Boop Betty:245-836-8357:635 Cutesy Lane, Hollywood, CA 91464:6/23/23:14500
Chevsky Igor:385-375-8395:3567 Populus Place, Caldwell, NJ 23875:6/18/68:23400

I'm interested in changing a birth date in a text file to a different date of 11/14/46. I want to do this without having to know the previous birth date and instead be able to search generically. I know the person's name that the birth date is associated with, so I can use that to make the substitution

I've tried this:

sed "s/^PersonsName\/[1-12]\/[0-31]\/[0-99]/11\/14\/46/g" txt.file

But it doesn't work and I'm not sure how to proceed

The suggested answers below haven't worked for me. I'm going to give some example data and see if this helps to clarify.

Popeye Sailor:156-454-3322:945 Bluto Street, Anywhere, USA 29358:3/19/35:22350

Let's pretend I'm trying to change Popeye's birth date (which is at the end), but I want to search without having to know his current one. I know using a regular expression is key here, but so far the examples I've seen haven't worked. Maybe providing the above example data will help

[Expected Output]

Popeye Sailor:156-454-3322:945 Bluto Street, Anywhere, USA 29358:11/14/46:22350

All I'm interested in changing is the birth date at the end to 11/14/46

I have a line that says...

Fred Flintstone, Bedrock USA

and I want it to look like...

Fred Flintstone, Bedrock USA ***

How do I append a few * to the end of the line using sed command?

Does anyone know how to use Sed to delete all blank spaces in a text file? I haven been trying to use the "d" delete command to do so, but can't seem to figure it out

I'm trying to get Grep to print all lines in a txt file that do not contain the numbers 834. When I try "grep [^834] file.txt" it still prints all the lines containing 834 but just doesn't highlight them.

I want to create a echo statement in a Bash script that will say "Today is (current date and time)".

so far I've tried:

today=date

echo Today is $today

but no luck

I need to set a path for a variable $week4 to be Week4/assignment so that typing cd $week4 will change the working directory to Week4/assignment/

I've seen a few examples of similar stuff on here, but I haven't been able to make it work for me. Help is appreciated!

Is it possible to set a fixed number for the "history" command to only show a certain amount of history items like 100, instead of everything from the beginning of time?

How do you change your prompt variable to display the current working directory (pwd), meaning so that when a directory is changed the prompt also changes to reflect the current directory you are in

I am trying to figure out an elegant way to create a new subdirectory in a series of existing directories.

I have 15 already created directories called Week1 through Week15. Within those directories, I'd like to create a new directory called "Assignments." I'm thinking this might require a loop of some kind, but outside of that I'm a little lost.

I know I can "cd" into each directory and then "mkdir Assignment" and repeat this step for all 15 directories, but I know there must be an easier way.

Any help/advice will be greatly appreciated!