03-05-2007
Quick Update:
I think I narrowed down the error. I didn't realize that the tail flag was actually the number 1 .... "tail -1" - doh!
The actual content of the log.txt contains 2 empty lines at the end.
So each variable was getting filled with blank info, due to the "-1" part. I need to either:
1 - put everything in one line in log.txt
2 - fix the tail commands to read the correct lines
Any recommendations as to which would be more efficient ?
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
Hello all! After searching through numerous helpful posts on these forums I am still having an issue with a task I am trying to accomplish.
I am trying to take data from an input file, store the contents as variables, and use the variables in the script.
The input file (input.txt) is... (2 Replies)
Discussion started by: screwed718
2 Replies
2. UNIX for Advanced & Expert Users
i have a file .NAMEexport MY_NAME=JOE
when i do this at the command prompt #. .NAME
$echo MY_NAME
$JOEi created a script called Run.sh . .NAME At the command prompt i did #sh Run.sh
#echo $MY_NAMEit returns nothing. What have i missed out? (7 Replies)
Discussion started by: new2ss
7 Replies
3. UNIX for Dummies Questions & Answers
Hi all,
I have a shell script that sets up the environment for an application running on UNIX - ksh. This script is run using:
. ./script_name XX
where XX is a parameter. I want to run it from another shell script but when I do it I don't get the envornment variables set up and the prompt... (3 Replies)
Discussion started by: solar_ext
3 Replies
4. Shell Programming and Scripting
normally when i type:
condor_q | tail -1
command line returns:
0 jobs; 0 idle, 0 running, 0 held
I want use the number in front of 'running' in a series of equality tests to submit more jobs when my queue gets low. Someone showed me how to do it a few days ago by setting an array equal to... (4 Replies)
Discussion started by: pattywac
4 Replies
5. Shell Programming and Scripting
Hi,
I need a simple csh script to read a file containing data like this
Buy Transactions : 175
Sell Transactions : 212
Server: sepo2
i want to read both field and its value and assign variables to each.. (2 Replies)
Discussion started by: pravsripad
2 Replies
6. Shell Programming and Scripting
Hello, I need a little help.
1. Edit /etc/profile so that all users are greeted upon login.
2. For the root account, set the prompt to something like "Danger!! root is doing stuff in \w", preferably in a bright color such as red or pink or in reverse video mode.
Thanks for help. (4 Replies)
Discussion started by: zhshqzyc
4 Replies
7. Shell Programming and Scripting
Hi
Does anyone know how to set any character as the field separator with awk/nawk on a solaris 10 box. I have tried using /./ regex but this doesnt work either and im out of ideas.
thanks (7 Replies)
Discussion started by: chronics
7 Replies
8. Shell Programming and Scripting
Hi,
In Cron file i'm using username and password hard-coded and now i wann to use environmental veraiables in cron file.
But Could you please guide me how to use these environmental variables in cron file ?
Thanks,
Shyamu.A (4 Replies)
Discussion started by: shyamu544
4 Replies
9. Shell Programming and Scripting
Hi,
I have around 10 environment variables in my shell script. i want to set this all in a file and just call that file in my shell script. How can i do that ? Please help. TIA! (6 Replies)
Discussion started by: qwertyu
6 Replies
10. Shell Programming and Scripting
greetings all, I have a task right now that is somewhat stumping me, and I am not sure what the best approach is to take it.
I have a text file that will contain something similar to the following:
first1, other1
first2, other2
first3, other3
first4, other4
I have to generate an... (14 Replies)
Discussion started by: jeffs42885
14 Replies
TAIL(1) BSD General Commands Manual TAIL(1)
NAME
tail -- display the last part of a file
SYNOPSIS
tail [-F | -f | -r] [-q] [-b number | -c number | -n number] [file ...]
DESCRIPTION
The tail utility displays the contents of file or, by default, its standard input, to the standard output.
The display begins at a byte, line or 512-byte block location in the input. Numbers having a leading plus ('+') sign are relative to the
beginning of the input, for example, ``-c +2'' starts the display at the second byte of the input. Numbers having a leading minus ('-') sign
or no explicit sign are relative to the end of the input, for example, ``-n 2'' displays the last two lines of the input. The default start-
ing location is ``-n 10'', or the last 10 lines of the input.
The options are as follows:
-b number
The location is number 512-byte blocks.
-c number
The location is number bytes.
-f The -f option causes tail to not stop when end of file is reached, but rather to wait for additional data to be appended to the
input. The -f option is ignored if the standard input is a pipe, but not if it is a FIFO.
-F The -F option implies the -f option, but tail will also check to see if the file being followed has been renamed or rotated. The
file is closed and reopened when tail detects that the filename being read from has a new inode number.
If the file being followed does not (yet) exist or if it is removed, tail will keep looking and will display the file from the begin-
ning if and when it is created.
The -F option is the same as the -f option if reading from standard input rather than a file.
-n number
The location is number lines.
-q Suppresses printing of headers when multiple files are being examined.
-r The -r option causes the input to be displayed in reverse order, by line. Additionally, this option changes the meaning of the -b,
-c and -n options. When the -r option is specified, these options specify the number of bytes, lines or 512-byte blocks to display,
instead of the bytes, lines or blocks from the beginning or end of the input from which to begin the display. The default for the -r
option is to display all of the input.
If more than a single file is specified, each file is preceded by a header consisting of the string ``==> XXX <=='' where XXX is the name of
the file unless -q flag is specified.
EXIT STATUS
The tail utility exits 0 on success, and >0 if an error occurs.
EXAMPLES
To display the last 500 lines of the file foo:
$ tail -n 500 foo
Keep /var/log/messages open, displaying to the standard output anything appended to the file:
$ tail -f /var/log/messages
SEE ALSO
cat(1), head(1), sed(1)
STANDARDS
The tail utility is expected to be a superset of the IEEE Std 1003.2-1992 (``POSIX.2'') specification. In particular, the -F, -b and -r
options are extensions to that standard.
The historic command line syntax of tail is supported by this implementation. The only difference between this implementation and historic
versions of tail, once the command line syntax translation has been done, is that the -b, -c and -n options modify the -r option, i.e., ``-r
-c 4'' displays the last 4 characters of the last line of the input, while the historic tail (using the historic syntax ``-4cr'') would
ignore the -c option and display the last 4 lines of the input.
HISTORY
A tail command appeared in PWB UNIX.
BSD
March 16, 2013 BSD