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sed will not write to same file

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Top Forums Shell Programming and Scripting sed will not write to same file
# 1  
Old 06-03-2013
Linux sed will not write to same file
I am a scripting noob, and having much trouble getting this script to run correctly. Upon start it should read the home directory and sort the files into a text file. Then have user enter a user name and insert it into line 1 of the same text file. Then have the date insert into the second line of the text file. Followed by a conformation message. So far it writes the the text file but creates separate files for the inputs. I am so lost... help anyone?SmilieSmilie

Code:
ls --sort=extension > directory.txt
echo "Enter you user name..."
read input
sed -n "1w a\ '$input'" directory.txt
date=`date`
sed -n "2w a\ '$date'" directory.txt
echo "The operation completed successfully."

Last edited by Scott; 06-04-2013 at 01:29 AM.. Reason: Please use code tags
# 2  
Old 06-04-2013
I find your description confusing.

What OS are you using? Do you care what shell is used to do this? (If so, which shell?)

What (described in English) do you want to want the output to be?

Do you want that output to be written to your terminal, or do you want it to be saved in a file? (If in a file, what is the name of that file?)

Is the following an accurate description of what you want:
Create an output file named directory.text that contains the following data:
  1. A user's name (the script is to ask the user to supply a name and save the response as the first line in the output file).
  2. The current date date and time should be saved as the second line in the output file.
  3. The remainder of the output file should be a sorted list of files in the current directory sorted with the primary sort key being the file name extension.
# 3  
Old 06-04-2013
Hi bbaumg02,

Here you go, with classic ed,

Code:
ls --sort=extension > directory.txt
echo "Enter you user name..."
read input
printf "1i\n$input\n.\nw\nq" | ed -s directory.txt

date=`date`
printf "2i\n$date\n.\nw\nq" | ed -s directory.txt
echo "The operation completed successfully."


ed works where sed won't
Enjoy , Have fun!.

---------- Post updated 06-04-13 at 03:44 AM ---------- Previous update was 06-03-13 at 11:06 PM ----------

bbaumg02,
Here how it ll look like:

Code:
$./script
Enter you user name...
JOHN
The operation completed successfully.

Code:
$ ls -lrt
total 20
-rwxrwxr-x 1 adms adms 236 Jun  4 00:39 script
-rw-rw-r-- 1 adms adms  98 Jun  4 00:39 test1
-rw-rw-r-- 1 adms adms 144 Jun  4 00:39 test3
-rw-rw-r-- 1 adms adms 144 Jun  4 00:39 test2
-rw-rw-r-- 1 adms adms   0 Jun  4 00:40 unix.com
-rw-rw-r-- 1 adms adms  79 Jun  4 00:40 directory.txt
$
$ cat directory.txt
JOHN
Tue Jun  4 00:40:42 PDT 2013
script
test1
test2
test3
unix.com
directory.txt
$

Hope this is what you were looking for.
This User Gave Thanks to rveri For This Post:
bbaumg02
# 4  
Old 06-04-2013
Quote:
Originally Posted by rveri
Hi bbaumg02,

Here you go, with classic ed,

Code:
ls --sort=extension > directory.txt
echo "Enter you user name..."
read input
printf "1i\n$input\n.\nw\nq" | ed -s directory.txt

date=`date`
printf "2i\n$date\n.\nw\nq" | ed -s directory.txt
echo "The operation completed successfully."


ed works where sed won't
Enjoy , Have fun!.

---------- Post updated 06-04-13 at 03:44 AM ---------- Previous update was 06-03-13 at 11:06 PM ----------

bbaumg02,
Here how it ll look like:

Code:
$./script
Enter you user name...
JOHN
The operation completed successfully.

Code:
$ ls -lrt
total 20
-rwxrwxr-x 1 adms adms 236 Jun  4 00:39 script
-rw-rw-r-- 1 adms adms  98 Jun  4 00:39 test1
-rw-rw-r-- 1 adms adms 144 Jun  4 00:39 test3
-rw-rw-r-- 1 adms adms 144 Jun  4 00:39 test2
-rw-rw-r-- 1 adms adms   0 Jun  4 00:40 unix.com
-rw-rw-r-- 1 adms adms  79 Jun  4 00:40 directory.txt
$
$ cat directory.txt
JOHN
Tue Jun  4 00:40:42 PDT 2013
script
test1
test2
test3
unix.com
directory.txt
$

Hope this is what you were looking for.
Hi rveri,
If that is what is wanted, why make it so complex? Why not just use something like:
Code:
printf "Enter you user name: "
read input
{      echo "$input"
       date
       ls --sort=extension
} > directory.txt
[ $? -eq 0 ] && echo "The operation completed successfully."

I don't see the need for ed or sed if this is the desired output.
# 5  
Old 06-04-2013
Thank you rveri, this worked perfect. Appreciate everyone's input and help.
# 6  
Old 06-04-2013
To summarize Don Cragun's post, I'm amazed how often people do ls -l then just throw away all that extra output. The -l is optional! You're making yourself do extra work!
# 7  
Old 06-04-2013
Quote:
Originally Posted by Corona688
To summarize Don Cragun's post, I'm amazed how often people do ls -l then just throw away all that extra output. The -l is optional! You're making yourself do extra work!
I have met several Linux users who -for some reason- always use ls -ltr, no matter what.

Some of them even think that without "ltr" they're not properly using it.

I don't know what book or Linux course teaches that practice or where does the habit come from.
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