I'm looking for a command to swap the even/odd numbered lines in a file. Example input file:
Code:
1
2
3
4
[code]...
Example output file:
Code:
2
1
4
3
[code]....
I'm sure there's a way to do it with sed, awk, grep and the like but it's been many years since I've used these commands on a daily basis and I can't seem to figure out the correct syntax.
I'm sure this is possible but I can't figure it out. I have a file formatted like this:
Code:
>SEQUENCE1
FGFD665:?@663:BBBBAA?A@<<4!1004699<7444399>???888455555?AAA?AABBB@@@<<<34
>SEQUENCE2
>&<4!1004699<7444399>???888455555?AAA?AABBB@@@<<<34BBB@@
>SEQUENCE3
???888455555?AAA?AABBB@@@<<<341004699<7444399>???888BBB@@
The odd-numbered lines containing >SEQUENCE# are the headers and the even-numbered lines containing a variety of characters represent DNA sequence read quality scores.
I want to replace all of the greater-than (">") symbols in the quality scores (even-numbered lines) with a "0" but I want to leave the greater-than symbols on the odd-numbered lines alone. I would just use sed -i '/^>/! s/>/0/g' $FileName but sometimes the quality scores begin with a ">" as well.
I'm sure there is a simple modification of a normal sed command with an "n" inserted somewhere but I can't figure it out.
I have this massive table file with some data in it and I want to replace some lines that are wrong with the correct ones that are in another table file of the same format. The wrong lines are not all together in a block but randomly distributed so I need to make a loop checking if the line is in the other file and if it is, replace it. I want to try and do it with sed or awk but I don't really know how to....
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View 3 Replies View RelatedThis should be simple but I can't seem to find what I am looking for.I want to search a text file for the existence of certain strings and execute a command if they exist, something along the lines of:
if <string> exists
command
or
if <any member of this list exists>
command
I know how to manually search a file with grep, cat, etc., but the "if this exists" part eludes me.
can anyone explain what is the use of swap -a command in solaris ? is there any equivalent command for swap in Linux ?
View 6 Replies View RelatedDoes one need to Check the Swap filesystem, from time to time
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View 2 Replies View Relatedi have a text file generated automatically from a script , but the result in the script is not ordered in a readable way, so i need your help to fix it using a shell command the text file contain data in this way :
Code:
0.147361 0.243688 0.081520 -0.446603 1.130529 NC_000846 Chordata
Rheiformes
Aves
0.091740 0.379224 0.021160 -0.088493 3.441356 NC_000857 Arthropoda
Diptera
[code]....
i want to arrange the data in this text file in a way that each line will concatenate the 2 lines after it , so that will be 1 line , i want all the lines to be treated in this way ,
I've seen a few tutorials that have commands and parameters on multiple line, like the one below:
Code:
chkconfig --levels 235 mysqld on
/etc/init.d/mysqld start
I can copy and paste this in Putty, but what if I want to manually type it? If I press return, the first line gets processed, so how do I insert a new line?
RAM for older machines like I use is fairly cheap these days. But flash memory is just as cheap or cheaper. So I'd like to ask about the feasibility of expanding my system's memory using flash memory. And about whether creating a partition for swap on the flash memory, or whether a swap file on the flash device, is the better way to go.
By flash memory I have in mind mainly USB sticks or what are sometimes called "pen drives." But I do also have CF and SD cards that, with the proper cheap adapter (one of which I already own for adapting CF) could be used to create extra swap space. So, what is the current consensus on the feasibility/advisability of using flash memory for swap? I've read about the limited write cycles of flash being an argument against using it for swap. But recent reading indicates to me that the limited write cycles problem applies mostly to older, smaller-capacity flash memory. Some will come out and say that, for larger-capacity flash memory, the life of the device is likely to exceed the amount of time your current computer will be useful (I think I've seen estimates in the range of 3-4 years life--minimum--for newer, higher-capacity flash memory).
A more persuasive argument I've heard against using flash memory for swap is that access times for these devices can be much slower than SATA, and maybe even IDE, hard drives. That would certainly dictate against using flash memory for swap.
So, how about some input on this issue? Anyone using flash memory for swap? If so, what kind (e.g., usb stick or SD/CF)? Are you using a swap file or a swap partition? How's system performance? Likewise, has anyone had flash-memory-used-as-swap die on them? The consequences would undoubtedly be dire. Also, has anyone measured flash memory access times to confirm or refute claims about slow access times? Are some types of flash memory better/worse than others in terms of access times?
I'm looking for a way to insert the number of lines in a file to the start of the aformentioned file. This should be simple but as I am not used to scripts in Linux, I am finding it tough going. I can find the number of lines in a file easily enough via
filesize=$(awk 'END {print NR}' $1)
but as for inserting this into the first line, i'm failing to do so. I've tried some of the other approaches on these forums but none so far have been able to do so.
I've tried:
sed '1i$filesize' $1
but sed i requires a string, not a variable so no go I've also tried:
mv "$1" "${1}.bak" 2>/dev/null || touch "${1}.bak"
cat $filesize "${1}.bak" >"$1"
but again with no luck as cat seems to need an input stream Just to recap, i want to insert a line at the start of a given file that holds the number of lines the original file has.
ie the file:
a
b
c
d
e
should become:
5
a
b
c
[code].....
How to break strings of command into multi-lines in crontab? e.g.
Code:
# the following is a very long a gruesome command to be run at 09:59 Monday to Friday.
59 09 * * 1-5 source $HOME/some-definitions; sh /usr/local/my/long/name/application/bin/hello $(date +\%Y\%m\%d) >>/var/log/my/long/name/application/log/hello.log
How to check the version of a program, in particular geant4, in linux using the command lines?
View 4 Replies View RelatedI am using RHEL 5.I have a very large test file which cannot be opened in vi.The content of the file has some 8000 lines.I need to view ten lines between 5680 to 5690.How can i view these particular lines in a large file.what is command and option i need to use.
View 1 Replies View RelatedI would like to know the command lines for;
-detecting the wifi in my house without being connected to it
-getting ips/macaddress from the people connected to the wifi
I have a large text file containing over 180k lines and another text file containing about 1k. I would like to remove lines in the 180k-line file that exist in the 1k-line file.
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View 5 Replies View RelatedI would like to modify the content of a text file in Linux, in the following way:=> the file has several of these lines:./run_pest3 ./g134366.04080_0.062 x 2_d043 1 0.43 results_EC=> I want to modify all lines to be:./run_pest3 ./g134366.04080_0.062 x 2_d043 1 0.43 results_EC0.062i.e., the last number of $2 should be "attached" to the end of $7, for each line.
View 5 Replies View RelatedI have a file similar to this:
I need to print the last line for each user into a file. The resulting file should look like this:
Is there a way that AWK can match lines from $1 and then print the last line into a file?
I'm trying to output two certain fields of a very large text file to 2 very small text files. Then take those files and add all the lines together to come up with a total from each file (two totals).
Here's what I've got:
Code:
#!/bin/bash
echo "0" > /media/in.txt
echo "0" > /media/out.txt
[code]....
Breakdown: Put 0 in a text file to be drawn by respective while loops for math later
Output last 60 integers to a file for total A (new integer every minute)
Output last 60 integers to a file for total B (new integer every minute)
The two while loops are supposed to be adding the lines together. The echo commands at the end are for testing purposes, just to see the output. However, when I run this, I get the output of
Code:
0 0
Which is obviously not what it's supposed to be. Is there a more efficient way to do this or am I missing something in the script that would reset the values to "0"?
looking to delete the last 6 lines of a file with sed. figured out how to delete the last line..but i want the last six.
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View 1 Replies View RelatedI have a file that contains 100 ligns, i need to write a script that read 70 lignes and redirect those 70 ligns to another files and these 70ligns have to be erased in the first file
when i write this command
head -70 somefile.txt>test.txt
or
sed -n 70p somefile.txt>test.txt
i have these 70 lines in the text.txt files
but these 70 lines have to be deleted inthe first file somefile.txt
I'd like to split a file into two, where the first file is the first two lines and the second is the remaining lines (third line to EOF).
View 2 Replies View Relatedi've got a file with sorted words - one on each line.How could it be possible to delete thouse lines that have words of length 1 or 2 (1-2 letters). I guess a good way it will be with AWK, n its fuction length(), but getting it, i dont know how to delete those very lines.
View 14 Replies View RelatedI have following contents
I want to grep "#2" and want the output as
How to using shell script?
When i want to remove particular lines containing a specific word in from entire document at a time,i am using the following command.
awk '$columnno !~/specificword/' inputfile > outputfile
But here, coulmn no is my problem, because iam having this in different columns. So i need a solution for it.
How to write such removal command without mentioning column no. , ie irrespective of column no, it has to remove all lines having that specific word.
