01-08-2009
Having been a Unix user for 20 years, most utilities have always seemed to fit into a standard way of doing things, but bc has always seemed to me to be quirky, and I've never got really on with it. awk seemed easy to learn in comparison and I've always found alternative ways to avoid using bc.
But, I love using vi while others dislike it because, IMHO, they've never really bothered to learn to use it properly. Maybe I should take some time to properly learn bc
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
:confused:
Is it possible to delete array elements dynamically.For instance,consider an array( a b c d ) ,now can i delete array (the third element 'c').So that the array becomes array(a b d)..
Thanks in advance!! (1 Reply)
Discussion started by: tj23
1 Replies
2. Shell Programming and Scripting
Hi,
I am writing a bash shell script. I would like to execute a statement only if an array contains a specific value. For example:
array=(1 3 5 7)
I would like to execute the statement only if the value 3 is present in ${array}.
Thanks for any help,
Mike (1 Reply)
Discussion started by: msb65
1 Replies
3. Shell Programming and Scripting
hi guys,
i have the following script and when i run it i get blank lines on the screen.. i am trying to display the contents of array var..
#!/usr/bin/bash
var=`awk 'NR>20&&NR<31' try.sum | awk '{print $4}'`
echo "${var}" (1 Reply)
Discussion started by: npatwardhan
1 Replies
4. Shell Programming and Scripting
hi guys,
i have an array called ARRAY which has elements in it... i am trying to assign elements of ARRAY to master_array..
i get a =: command not found error..
i=0
while
do
${master_array}=${ARRAY}
((i++))
done
is there something i am missing? (4 Replies)
Discussion started by: npatwardhan
4 Replies
5. Shell Programming and Scripting
Hi all,
I have a file that contains many lines, but only a few are of my interest, so I'm cutting it with grep + awk, and the result I get is for example
line 0
line 1
line 2
line 3
line n
Now I want to store each line in an array "cell" so I can use it later calling to
${array},... (2 Replies)
Discussion started by: TuxSax
2 Replies
6. Shell Programming and Scripting
trying to sum elements in an array using bc and getopt,i have a file with names and thier vaules if the names appears 3 times i should multiply its value with 3 then find the sum of all the elements together
cat foo.txt
max 2.3
henry 3
fransis 4.5
max 2.3
henry 3
max 2.3
it should... (1 Reply)
Discussion started by: elginmulizwa
1 Replies
7. Shell Programming and Scripting
I have the following code and for some reason when I call the program using
/home/tcdata/tatsh/trunk/hstmy/bin/bash/raytrac.bash --cmod=jcdint.cmod
I get
hasArgument =
hasArgument = true
Somehow the array element is returning even though I have not chosen the option.
... (41 Replies)
Discussion started by: kristinu
41 Replies
8. Shell Programming and Scripting
Hello all .
I have two arrays.
${ARRAY_MOUNT_POINT_CAPACITY}
${ARRAY_MOUNT_POINT_CAPACITY}.
Whats the synatx of subtracting their values , placing them in variable V1 and then echoeing it ???
Ive tried expr and let ...gives me ./test_code.sh: difference: bad number (3 Replies)
Discussion started by: Junaid Subhani
3 Replies
9. Shell Programming and Scripting
Hi all,
i'm making some test on a data file. Imagine i have two columns inside it :
80377,20
80377,20
80379,19
80378,20
80380,20
80382,20
80381,21
Just to understand how can it works, imagine to subtract 100 to the number in the first column when the other one in the second... (4 Replies)
Discussion started by: Board27
4 Replies
10. Shell Programming and Scripting
I am sharing a code snippet.
for (( i=0; i<=$(( $count -1 )); i++ ))
do
first=${barr2}
search=${barr1}
echo $first
echo "loop begins"
for (( j=0; j<=5000; j++ ))
do
if } == $search ]]; then
echo $j
break;
fi
done
second=${harr2}
echo $second (2 Replies)
Discussion started by: ngabrani
2 Replies
LEARN(1) General Commands Manual LEARN(1)
NAME
learn - computer aided instruction about UNIX
SYNOPSIS
learn [ -directory ] [ subject [ lesson ] ]
DESCRIPTION
Learn gives Computer Aided Instruction courses and practice in the use of UNIX, the C Shell, and the Berkeley text editors. To get started
simply type learn. If you had used learn before and left your last session without completing a subject, the program will use information
in $HOME/.learnrc to start you up in the same place you left off. Your first time through, learn will ask questions to find out what you
want to do. Some questions may be bypassed by naming a subject, and more yet by naming a lesson. You may enter the lesson as a number
that learn gave you in a previous session. If you do not know the lesson number, you may enter the lesson as a word, and learn will look
for the first lesson containing it. If the lesson is `-', learn prompts for each lesson; this is useful for debugging.
The subject's presently handled are
files
editor
vi
morefiles
macros
eqn
C
There are a few special commands. The command `bye' terminates a learn session and `where' tells you of your progress, with `where m'
telling you more. The command `again' re-displays the text of the lesson and `again lesson' lets you review lesson. There is no way for
learn to tell you the answers it expects in English, however, the command `hint' prints the last part of the lesson script used to evaluate
a response, while `hint m' prints the whole lesson script. This is useful for debugging lessons and might possibly give you an idea about
what it expects.
The -directory option allows one to exercise a script in a nonstandard place.
FILES
/usr/share/learn subtree for all dependent directories and files
/usr/tmp/pl* playpen directories
$HOME/.learnrc startup information
SEE ALSO
csh(1), ex(1)
B. W. Kernighan and M. E. Lesk, LEARN - Computer-Aided Instruction on UNIX
BUGS
The main strength of learn, that it asks the student to use the real UNIX, also makes possible baffling mistakes. It is helpful, espe-
cially for nonprogrammers, to have a UNIX initiate near at hand during the first sessions.
Occasionally lessons are incorrect, sometimes because the local version of a command operates in a non-standard way. Occasionally a lesson
script does not recognize all the different correct responses, in which case the `hint' command may be useful. Such lessons may be skipped
with the `skip' command, but it takes some sophistication to recognize the situation.
To find a lesson given as a word, learn does a simple fgrep(1) through the lessons. It is unclear whether this sort of subject indexing is
better than none.
Spawning a new shell is required for each of many user and internal functions.
The `vi' lessons are provided separately from the others. To use them see your system administrator.
7th Edition October 22, 1996 LEARN(1)