I tried using the tail command in my shell script and storing that value in a variable a but an error keeps coming. Is there any other way to store the output of a command into a variable. Cannot Read text from text file and store it in a variable using shell script. The thing is I need a number from the file new.txt and use that number in my script
#!/bin/bash
a = `tail -1 new.txt|head -n 1`
echo $a
Suppose I want to account number of files beginning with abc , I can use "ls 'abc* | grep abc | wc -l", this will return me a number.
I want to store this number in a variable, say var1, so I tried
1. "ls 'abc* | grep abc | wc -l |read var1", but this didn't work as var1 has no value somehow.
2. var1='ls 'abc* | grep abc | wc -l', this just assign the entire string "ls 'abc* | grep abc | wc -l" to var1, which is not I wanted.
I don't want to store the value to a temporary file and then read the value from that file. I think there should be a direct way to get the value, but don't know how. I know in tcsh, one can just use set var1='ls 'abc* | grep abc | wc -l', but it also doesn't work in bash. Can anyone give any clue about this?
I need to store the output of bitset() in a variable ... is it possible in c++?
View 1 Replies View RelatedI want to store the result of wc -l as a variable so I can use it later in my script...so far unsuccessfully.
I have tried this:
set `echo awk '{ print $1, $6}' | wc -l` | echo $1
but it is far from working.
I am trying to watch a command and try to log it into a file. I tried
watch -t -n 10 "(date '+TIME:%H:%M:%S'
; ps aux | grep "pattern" | wc -l)" >>
logfile
and am expecting a result like
TIME: 10:32:30 12
TIME: 10:32:40 18
TIME: 10:32:50 2
to be stored in logfile. However, when the logfile has unprintable characters in in. How do I get this kind of output from the command li
Code:
ls Again the command can be stored in a variable and then executed. Like
Code:
var=ls
&var
The above two codes are the same. The problem occurs when we try to pipeline it. Consider the following problem:
Code:
ls | grep *
works fine...but when we try to store it in a variable and run the command there is an error.
Code:
var="ls|grep *"
$var
how to store this kind of commands in a variable?
Was trying to write a shell script that has if conditional statements to decide different arguments for a command.Basically:
Code:
if [ "$1" = 1 ]
then
[code]...
For example, when using bash you can use
Code:
to execute the previous command or
Code:
!<number> to execute the Nth command(use history to see the list). Or you can use
Code:
cd !-2:1
to cd into the value in the first field that was executed 2 commands ago Anyhow, say I run a command and the output is a path. Any way to cd and then some variable where OUTPUT of the previous command was stored? A variable that always stores the OUTPUT of the last command.
I need to find one RUNNING word in latest created logs.
and as soon as i will get RUNNING WORD , i have to execute another Unix Command.
I wrote following script code...
In my script, I need to get execution time of a command (say 'ls') in mili seconds level. For this i tried using "time" command to retrieve the total execution time in milli seconds. But, the problem is that, how to save the output of time command in a variable. The format of the command is like "time ls -R /opt" Going further, the o/p of 'time' command is:
real 0m0.003s
user 0m0.004s
sys 0m0.000s
Here, in my script, I would like to use only middle line "user 0m0.004s" saved to the variable but unable to find out the way.
Kernel 2.6.21.5, GNU/Linux (Slackware 12.0).In this script,
Code:
semoi@darkstar:~$ cat rename4.sh
#!/bin/bash
INPUT="k3b_audio_0_04"
[code]...
so i wrote myself a very simple hellworld program in c++
...the usual stuff
int main()
{
[code]...
I would like to grep two numbers out of a text file, and divide them.
Here is the script code...
It feels like grep saves a new line too? or what is happening? i simply can't divide them, as it handles the variables as they are empty (and prints the two numbers although they were not printed
On command line I have no problem storing a variable e.g
Code:
:~/bin$ process=`ps -ef | awk ' $8 == "idesk" { print $2 }'`
:~/bin$ echo $process
26736
:~/bin$
When I try to incorporate this into a shell script I get a blank.
Code:
:~/bin$ cat process_idesk
#!/bin/bash
process=`ps -ef | awk ' $8 == "idesk" { print $2 }'`
[code]....
The process_idesk script has been chmoded to be executable by the user. I'm sure there must be a silly omission on my behalf.
I have this script:
Code:
a=awk'{print $8}' f1.txt
How can I make it store lines in $a ? In the way above it creates one big line.
I am not able to execute a multiple sed statement using pipe filters in a variable. i am trying to extract a path from a file and then working on that path to change a few letters within the path by going through another sed statement.
the code looks like this code...
i need to count the number of files and put the output into a variable. i used wc -l filename but i couldnt find an option to put the output to variable. example if the number o line is 5, i need the output of echo $x is 5.
View 3 Replies View RelatedI need to create a single line of output from multiple and variable lines of input in a Linux bash shell script.
My input file looks like this:
Where there may be any number of umsecondaryphonenumber lines; if there is not a umsecondaryphonenumber line for a telephonenumber, I don't want to write any output.
So, the output file should look like:
The script I have so far is:
My question is - how do print each of the elements of an array in one record - i.e. what do I put in place of howdoiprintarray?
I have two students whose windows laptops are riddled with malware and not working properly. They want me to help them install Linux (which we use in school), but they are concerned about their iTunes.
Having avoided iPods as "defective by design", I know nothing about iTunes whatsoever. However I remember reading about DRM locking and such problems that have me concerned that I won't be able to do it.
Where does iTunes store its stuff?
Can I copy its data store to an external drive, and then into a linux home?
Then will it work on wine, or can another manager (rhythmbox etc) access the itunes data?
Alternatively, if I partition the drive and install linux, can rythmbox/wine/something access itunes data on the win partition?
Supposing they are buying music through iTunes, what will happen to that account?
Finally, one of them has an iphone. Does that work with linux?
Ironic that an apple application is blocking migration away from windows.
I am using openSUSE 10.3.When I install software from tarball then to record time required I send output of date to beg.txt(when installation begins) and end.txt (when installation finishes).How can I append output of date to a file so I don't need two files?
View 4 Replies View RelatedI am working on telnet session and excuting commands. I am able to redirect or store expect output to log file but now i want to store in excel file like ispreadsheet showing details of commands and its responses
View 2 Replies View RelatedI want to run gsettings list-schemas (which return a list of about 100 names separated by spaces)and somehow direct each name one at a time as the input to this command:gsettings list-recursivelyI've tried it with awk, and standard | piping and also as a string variable strvar=$(gsettings list-schemas) and using the $strvar as the input butam missing something in between I'm sure like for - while or proper syntax of awk etc
View 3 Replies View RelatedI want to use the output of a previous command as a parameter to another command. For example: to know where "nice" is stored i typed: which nice output: /usr/bin/nice now the second command i typed is: ls -l /usr/bin/nice Is there a way to have a single command like: ls -l which nice ?
View 4 Replies View RelatedI was reading that if I want to do a one time scheduled command, I should use at, which I've never done, as opposed to cron, which i'm kinda familiar with. But what I want to do is reboot my server at 3am tomorrow and force it to check the file systems with a shutdown -rF. For this do I even need to use "at" or could I just say shutdown -rF 3:00.Will that also know that I mean 3am tomorrow and not say in 3 minutes from now or 3pm?
View 14 Replies View RelatedWhen I run this command from shell, it runs ok
export REVS=`svn info svn+ssh://svn.myone.ca/var/svn/story/trunk/lib |grep 'Last Changed Rev:'| awk -F: '{print $2}'`
However when I save it into a file called test.sh (of course, I chmod it with +x), I got error "export: 2: bad variable name"
Here is the file:
#!/bin/bash
export REVS=`svn info svn+ssh://svn.myone.ca/var/svn/story/trunk/lib |grep 'Last Changed Rev:'| awk -F: '{print $2}'`
I am using ubuntu.
I do this:
Code:
a@b:~$ export A=hi
a@b:~$ echo $A
hi
a@b:~$ bash -c "export A=blah; echo $A"
hi
a@b:~$
Why doesn't the bash command print the new value of $A? Is there a way to make it do so?
I am using CentOS5.5 & everytime it is showing command not found. If I export the path as below it will be working fine until a reboot. Again same error i.e command not found if I open new terminal. Every time I am exporting as below:
#export PATH=/sbin/:$PATH
#export PATH=/usr/sbin/:$PATH
#export PATH=/usr/bin/:$PATH
#export PATH=/bin/:$PATH
How can I set these permanently as that the paths should automatically be exported for everyone user whenever the system boots. And command completion also should happen for eg. #fdi (press tab), then it should show available options such as fdisk, etc.
I want to use PROMPT_COMMAND variable to build a history of all the commands i execute. So Basically i want to append the last executed command to my own command log file. How can i find the last executed command ?
I want to add PROMPT_COMMAND="echo $last_executed_command >> my_command_log" But I am not sure how to find the last executed command
I am assigning "find" operation output to a variable. I also need to have error info / stderr if nothing is found in the same variable itself.
e.g.
a=`find . -name "hello.txt" -type f`
I do not want any temp files to be in between infact, redirection.
New to ubuntu and shell scripting in general... currently I stored some data into a text file. Right now, I would like to output the data from the text file and store it into a variable. Here's what I have so far:
READ_FILE=$(cat $FILE_NAME)
This definitely works and READ_FILE has the necessary data. However, this command will trigger an output to std output and I will see data on the screen, which is not what I want. I tried:
cat $FILE_NAME | $READ_FILE
and various other variants of this. It does not output to std output but neither does anything gets stored into $READ_FILE. I tried:
cat $FILE_NAME >> $READ_FILE
and it arrived at an error of "ambiguous redirect".