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 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.
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?
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?
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]...
Have this script which is reading in a series of files, one at a time with while-do-done loop, each file goes through various greps/awk's where this info is then saved to various files for later use. i.e....
Script is being run on Linux Red Hat,
In one of the grep/awk's the output (currently) are 2 columns (min max), i.e....| awk '{print $1, $2}' | sort -u which outputs (e.g.)
The number of "min max" pairs varies from file to file. Want to output a single column of unique numbers from the min max pairs & get the number of them for input to a file...i.e...
Where <PROCESS> is some process/technique that will generate a single column of integers (increment of 1) to pipe into the next one (sort -u)
i.e. (example from above)
Have tried command seq - only works for single pair input i.e.
Is there any command like seq etc which will output a single column based on a input of min max numbers (increment 1) to pipe onwards to next command?
I've written a simple server in linux used fork to create a FIFO pipe.The server create two FIFO pipe.One for server read data from client and write data to client.Then another pipe for client read data from server and write data to server.When the server read data from a client used server-pipe and then write data to client.But ,if the client no read open the pipe,the server side write will be crashed because of a broken-pipe SIGPIPE. How to check whether the read side is opened?Or,how to catch the SIGPIPE,and then my server will still execute on,not crashed!!
View 5 Replies View RelatedI am running a script that can run as many as 10 simultaneous times. During my testing, i noticed that if the script starts while another is in process, it inherits the $1 variable, which is always different.For example, the script starts with "scripthere.sh entry1", anther one starts almsot at the same time "scripthere.sh entry2". As the script is running, the second instance inherits $1 from the first script. So instead of $1 entry2, it shows up as entry1. how I can store $1 so that its unique to that instance of the script only?
View 2 Replies View RelatedI have to pull certificate from multiple computers which are on network and store it in a single fie or each file belong to a particular computer.I am using certutil -store to import the certificate.
View 4 Replies View RelatedWhy do I still get mutiple definition of "_my_variable" error even after I used the #ifndef preprocessor in my hpp file?
This is my scenario
I have:
1. A.cpp (including X.hpp)
2. B.cpp (including X.hpp)
3. X.hpp
[Code]...
I have this complex log file filled with entries like
test1-G1/0/0-100-QOS-7001923-ROUTING (ClassMap)
Action: Resolved New
sysName: test1.local
[code]...
I am trying to think of a logic where my file contains some data I had to read and do some processing. Issue is that file contains data multiple times. For example:
:::::::::::
var1=value1
var2=value2
[code].....
I have to read first paragraph of variables and do some processing and then move on until the end of file. Variable names are same in whole file but for each paragraph the value is different. I can't think of a logic to attain this task. How can I do it? It should be a simple bash script, but I am not able to work out.
I'm trying to use the output from gdialog's input box in another command with no success. code...
View 3 Replies View RelatedI 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
I 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 need to store the output of bitset() in a variable ... is it possible in c++?
View 1 Replies View RelatedSearched the forums for solution & am not seeing oneWrote a simple script to find Trash folders on Lucid and delete them
Code:
#!/bin/bash
sudo find / -regex ".*Trash[-]?[0-9]+?" | while read -e line
[code]....
How do you do things like list directory contents, mov/copy files, make directoriestc. in C?
View 1 Replies View RelatedI need to do mount/umount operations in my c program. But my program can only be run under normal user. However, the user who run my program have sudo priviledges to do mount/umount operations. How can i apply the sudo privileges in the mount(2) system call?
View 6 Replies View RelatedI need a tool that will enable me to manage files and other operations from another computer, access to my server. VPS and other host they usually provide cpanel and other webadmin app to do that.
I need advices on the followings:
1. FTP, allow me to access to my folder, like a web host
2. Access to config the server settings
3. Probably a GUI similar to cpanel
I'm trying to read content of file to variable and use this variable in for loop. The problem is, when I have c++ comment style in file - /*. Spaces in line are also interpreted as separated lines.
For example:
Code:
Changing $files to "$files" eliminate these problems but causes that whole content of variable is treated as one string (one execution of loop).
my script has a variable which comes in the form +00.00 +0.00 -00.00 or -0.00 (the numbers can be any in that form) for any that have a + symbol I need to remove the +, but if it has a - symbol it needs to stay.
i need to make a new variable with the string from the old variable btut without any plus sign. I have tried a lot of different ways with no success, each thing I tried either left the + or removed the entire string. I think this should work but doesn't
foo=+12.40
bar=${foo#+}
how I can search within a variable and assign the results to a new variable. I'll use the following as an example -
cars="Audi BMW Cadillac Chevy Dodge Ferrari Ford Mercedes"
list=`echo ${cars} | egrep -o '<A?+|<C+'`
with the echo command I get the following output assigned to list -
A
C
C
What I'd like to get for output is -
Audi
Cadillac
Chevy
how I could do this regardless of upper/lower case letters?
how to perform floating point operations in kernel? i answered that its impossible to perform floating point operations in kernel.but he is telling that its possible but with some feature to be added.can any body know about this perfectly??
View 1 Replies View RelatedI'm trying to split a text file into various parts. Everything in between "123" and "break" (including linebreaks) goes into the splitted file.
e.g. using this text file:
This should split into 4 files. However I'm only getting 2 files: one for the line "123break" and one for "123 blah break". The two occurrences that contain linebreaks are being ignored. The .* part of my match should capture linebreaks seeing that I'm using the /s modifier shouldn't it? Even when I use the match /(123 break)/gs it still doesn't capture the first occurrence. I'm using Perl v5.12.3 (from ActiveState) on Windows XP. The text file is also in Windows format.
Code listed below.
The above code generates two files Output_1.txt and Output_2.txt which contain "123break" and "123 blah break" respectively. I want it to generate four files.
We all know linux kernel base layer is made up of structures, in which every object of kernel is well defined. Structure members correspond to object properties required to define object behavior.
For example if we take case of File system.It composed of four objects , superblock objects, inode objects, file objects and dentry object.Each having well defined structure which is being operated by system call handler and by system call service routine in the kernel mode.
Now my question is even in kernel mode we do not have some mechanism by which we can get access to pointer of these structures.We have some macro.
If I want to manipulate structure on my on way, or performing some more operation defined by me.For example after the crash of Hard Disk Drive, having ext2/3 file system, If i want to know all the inode pointers, and block details.
Can I have some way out to do desired operation ??
mechanism to operate on these base label structures, even in kernel mode ..
included shell script inside c program, and i wanted to assign the value of c variable to shell variable..Can any one please suggest me how to do it?
View 8 Replies View RelatedThis loop is part of a bash script which takes multiple arguments.
Code:
for ((i=1;i<=$number;++i)) ; do
offset=$(($i+5))
[code]...
In shell, I execute "./ffmpeg -f h264 - | xxx"
Now I hope use execl function to execute above operations,
I call execl("/bin/sh", "sh", "-c", "./ffmpeg -f h264 - | xxx");
but ffmpeg doesn't work, it seems that "|" pipe don't work.
how could I solve this?
I understand that $! is the PID of a command. For example:
Code: #!/bin/bash
myprogram &
echo "PID of myprogram is $!"
I'd like to send the output of "myprogram" to both console and to a log file using the "tee" command but I also want to store the PID of "myprogam". Something like this:
Code: #!/bin/bash
myprogram | tee ./logfile &
echo "PID of myprogram is $!"
The problem is that $! is now the PID of "tee" rather than the PID of "myprogram".