filehandle

问题 I'm developing an iphone app, I need to create a certain size file on filesystem and filled with NO data first, then seek to a offset and write data when get data from somewhere else How can I do it? 回答1: The lseek BSD function is explicitly capable of that. man lseek : The lseek() function allows the file offset to be set beyond the end of the existing end-of-file of the file. If data is later written at this point, subsequent reads of the data in the gap return bytes of zeros (until data is

问题 How to determine if I can write the given number of bytes to a filehandle (socket actually)? (Alternatively, how to "unread" the data I had read from other filehandle?) I want something like: n = how_much_can_I_write(w_handle); n = read(r_handle, buf, n); assert(n==write(w_handle, buf, n)); Both filehandles (r_handle and w_handle) have received ready status from epoll_wait. I want all data from r_handle to be copied to w_handle without using a "write debt" buffer. In general, how to copy the

问题 I am trying to save and load files on a project that is coded on libgdx. Which means that i cant use a buffered reader because android wont read it.. and i cant move the project to android because it has to be in the core... after days and days or understanding all.. now i am trying File handing which should work right?? but i cant get it to read line by line.. it puts all the text in on string.. Help plzz.. also is my understanding correct and saving and loading is waaaay more complicated

问题 I'd like to write data to a file, but the file handle should be opened with access permissions for a specific user. Thus, the following statement: open (FH, "> $filename") or die "$@\n"; would allow writing to a file as that particular user. Is there a way to do this within a Perl script, without the entire script being run with sudo -u $username ? 回答1: There are two established ways. Stackers, you are invited to edit this answer to fill in the drawbacks for each. Run the program with sudo .

问题 I'm trying to figure out the proper PBP approved way to process a multi line string one line at a time. Many Perl coders suggest treating the multi line string as a filehandle, which works fine unless you have "use strict" in your script. Then you get a warning from the compiler about not being able to use a string as a symbol while strict refs is in use. Here's a simple working example of the problem: #use strict; use warnings; my $return = `dir`; my $ResultsHandle = ""; my $matchLines = "";

问题 test.fa.gz file contains multiple 4 lines as blow: @HWI-ST298:420:B08APABXX:3:1101:1244:2212 1:N:0:TCATTC GGCAAGGCACTTACTTTACAGCTAAAGAAGTGCAGC + @@@FDFFDFHCFDACGHC<<CCFEHHFCCFCEE:C? What I want to do is to read every four lines of *.fq.gz file in parallel with OpenMP. The code blow could be compiled successfully, but will show incorrect results sometimes. In each for loop, I used 4 times of getline() to read the file. I'm not sure how OpenMP will handle the multiple jobs in each for loop and

问题 I am very new to JavaScript so I am guessing, that this problem will be fairly simple for most of you guys (or at least I hope so...) I have this SweetAlert Code. It asks the User to upload two images and one text. I am able to add the text to my database but I am struggling with the images... I know that I need to pass the Images using the File Handlers, but I don't know how... This is my Server that I run my Code on: https://mars.iuk.hdm-stuttgart.de/~mk304/Web_Projekt/webpage/ui/sweetalert

问题 I am trying to add a file upload to an existing web page. Every time I upload I get a file that is corrupted. I made sure to set binmode on the file handle. I also have my input enctype set to multipart/formdata in my form. My code is as follows $article{upload_file_name} = $cgi->param( 'upFile' ); $article{upload_file} = $cgi->upload( 'upFile' ); if ( $article{upload_file_name} ne "" or $article{upload_file_name} ne null ) { open( UPLOADS, ">$uploads_dir/$article{upload_file_name}" ) or die

问题 I have a text file that looks like the following: Line 1 Line 2 Line 3 Line 4 Line 5 filename2.tif;Smpl/Pix & Bits/Smpl are missing. There are 5 lines that are always the same, and on the 6th line is where I want to start reading data. Upon reading data, each line (starting from line 6) is delimited by semicolons. I need to just get the first entry of each line (starting on line 6). For example: Line 1 Line 2 Line 3 Line 4 Line 5 filename2.tif;Smpl/Pix & Bits/Smpl are missing. filename4.tif

问题 When trying to execute this piece of code: public void load(String filename) { FileHandle file = Gdx.files.external(filename + ".bim"); Json json = new Json(); String text = file.readString(); datamap.clear(); datamap = json.fromJson(HashMap.class, text); I get an error: Exception in thread "LWJGL Application" com.badlogic.gdx.utils.GdxRuntimeException: com.badlogic.gdx.utils.SerializationException: Class cannot be created (missing no-arg constructor): com.bvo.easyBim.Model.Cursor at com