Programming :: How To Write Using Fwrite Without Affecting Existing Content Of File?
Oct 30, 2010
How can I write to a file multiple times using fwrite without affecting the previous writes?The method shown below accepts a file name, buffer and offset. The method opens the file in reading/writing mode and writes the content of the buffer at offset.
I have a few partitions on my hard-drive, one for Ubuntu, one for Windows 7 and another for general data storage. When I installed Ubuntu, I was presented with a GUI which allowed me to easily reassign storage space from the latter two to create the former. Is there any way to get to something similar, from which I can adjust the proportions of the partition sizes, without affecting their content?
My employer issues pdf files with everyones work schedules. I copy the content and save it as plain text in a file called unformatted (hope to be able to automate this step someday). Im working on a SED script that reduces unformatted to only display what I want to see and saves the result in a file Iïve named formatted. After that I have to manually copy formatted and save it with that days date as a filename e.g. 2011-02-25 or whatever day is scheduled in the pdf, for use on a mobile device (Nokia N900). I noticed that the date occurs on certain lines in the file so I added a line like:
sed -n 's/^Date: (201[1-9])/([0-1][0-9])/([0-3][0-9]).*/1-2-3/p' < unformatted >theDate That creates a file theDate with the date in it that I wish to use as the filename for this particular instance. So I would like to skip the file formatted all together and have the sed- script write to a new file using the content of the Date as a filename, but how do I make that happen? And of course it would be more elegant if I could skip the intermediate theDate file as well.
go about developing this add-on. i am testing this on my xbmc-live set-up; i am fairly affluent in bash/ c but unfortunately i dont have experience with python.i trimmed the data using this bash 1-liner so the output looks like:
Now I want to append contents list2.cfg to list1.cfg(It ispposible using cat list2.cfg >>list1.cfg) but I want to check if content of (record) in list2.cfg is present in list1.cfg then dont append it otherwise append it.
i need to check group of URLs and there https requests from browser. Recently i got some command line web browsers to know the HTTPS status of the URL like curl, wget etc... Now all of i need to do is write a shell script. I will put all my URLs in a text file and my shell script should read each URL one by one and log the status along with the corresponding URL.
I a csv-file (A.csv) with a total of 4.600.000 lines. Thats to many and only a few is necessary. I have a txt-file with 150 lines (X.txt) (all lines is dataset from a mainframe and looks like abc.def.123.456. How do I remove lines from A.csv where none of the dataset from x.txt is present?
I'm woring on a personal research project and would like to know if there are lilypond parsers for python available or I'll have to create my own. Just in case you are wondering: I don't need to typeset the content of the lilypond file, just understand what's written in the file (what notes, what duration, when in time to play each one, etc). [url]
If you have the value 100 in File1 and the value 5 in File2, how do you write a script to divide the 100 in File1 by the 5 in File2 in Linux Bash Shell?The operating system I am using is Ubuntu 10 and object is to write a script to accomplish this task.
I have ubuntu server 10.4 installed on an Intel SS4200-E, which I have configured without any RAID. This machine acts as a media server to another PC. The other PC runs Windows 7 Ultimate. I have 3 1TB hard disks connected to it, and the file system on all the 3 are NTFS. I have mounted the hard disks as ntfs. I have made the folders on all the 3 hard disks shareable. I have configured Samba to make the folders on the hard disks "visible".
The ubuntu machine is in a headless configuration (it doesn't have any VGA card where can connect a monitor). I can configured SSH on it, so I can use putty from the Windows machine to logon to the ubuntu machine, but it is text based only. I am able to see all the 3 disks from the Windows machine. I am able to read/write into 2 of the disks. I am able to read, copy and delete from the 3rd disk, but not write new content to it.
I have the following problem. I call a C++ program from a Java servlet by using Runtime exec. The OS is ubuntu and I use Netbeans 7.0 with Glassfish 3.1 web server.The program executes but it does not open and write into a specified file in a specified folder. The same C++ program compiled under Windows opens and writes this file.How can I solve this problem in Linux?
I'm running a simple backup and log script that is cronjobed to run twice a day. So currently, when new data is added to the log, its added to the direct bottom of the log file. However, I would like to have it printed to the very top of the log. The code is attached, I can't quote it in here because I am a new user and the system thinks I have url's in it, when they are just paths.
I am a beginner with php ,trying to work my way through. I have a file to be written with particular indentation and by appending some special characters... this is the o/p file i wanted. could anyone please guide me as to how i can write it? code...
I have 3 c files(one of them forks out 5 instances) all writing to one log file. Now to avoid the confusion of opening and closing in each application or instance and running into a situation of not having closed a file I decided to open and close the log file inside the log function for each write.
So what I do currently is fopen, flock, fwrite, unlock, fclose for each write. All the log messages from all the files get written fine and there are no errors but I see a performance hit. The applications talk to each other using SHM(shared memory). So when I try to set a timer and check number of messages lets say I get X messages. Each time I remove or add a log call the number of messages changes. When it is a 1 sec or 5 sec timer it doesnt make a very big diff..few hundreds but when I check it over a longer period..every log call added decreases 1000 messages in count. So I want to know what is an efficient way of implementing the custom log across the application.
i am working on this thread: [URL] if it is better to open a file every time i need to write to it or should i keep a file open the whole time and when i am done with the script, close it and sendmail it out?
Or i just thought of this: i could keep concatenating to a string and just sendmail when done.
i want to close the program if the content of the file /tmp/file_name is 1 (just the number 1).
dont need to check all the time, just when start the program.
something like this:
Code: "read the /tmp/file_name" "check if the content of the file_name is 1" "if not, do something"
what i need is very simple to do in shell script:
Code: go=`cat /tmp/file_test` # "cat /tmp/file_test" read the content of the file_test if [ "$go" -eq "1" ]; then # if the content of the file_test is 1 echo "ok, ready to exit now"; # now i can put the exit command fi