I have to place a 1MB size check on my files to be uploaded . Now in code (using c#) i have to mention the size in bytes . Should i check the size of upload file with the value
MaxSizeInBytes = 1048576 OR MaxSizeInBytes = 1000000 .
In most operating systems, files of 1048576 bytes will show as "1 MB" (and more importantly, files of 1000000 bytes will show as "less than 1MB"). So the user will have the expectation to be able to upload such a file if the form says it accepts "1 MB files".
Related
I have a FAT16 drive that contains the following info:
Bytes per sector: 512 bytes (0x200)
Sectors per cluster: 64 (0x40)
Reserved sectors: 6 (0x06)
Number of FATs: 2 (0x02)
Number of root entries: 512 (0x0200)
Total number of sectors: 3805043 (0x3a0f73)
Sectors per file allocation table: 233 (0xE9)
Root directory is located at sector 472 (0x1d8)
I'm looking for a file with the following details:
File name: LOREMI~1
File extension: TXT
File size: 3284 bytes (0x0cd4)
First cluster: 660 (0x294)
However, I would admit that the start of the file cluster is located at sector 42616. My problem is that what equation should I use that would produce 42616?
I have trouble figuring this out since there is barely any information about this other than a tutorial made by Tavi Systems but the part involving this is very hard to follow.
Actually, the FAT filesystem is fairly well documented. The official FAT documentation by Microsoft can be found by the filename fatgen103.
The directory entry LOREMI~1.TXT can be found in the root directory and is precedented by the long file name entry (xt, lorem ipsum.t → lorem ipsum.txt), the directory entry is documented in the «FAT Directory Structure» chapter; in case of FAT16 you are interested in the 26th to 28th byte to get the cluster address (DIR_FstClusLo), which is (little endian!) 0x0294 (or 660₁₀).
Based on the BPB header information you provided we can calculate the the data sector like this:
data_sector = (cluster-2) * sectors_per_cluster +
(reserved_sectors + (number_of_fats * fat_size) +
first_data_sector)
Why cluster-2? Because the first two clusters in a FAT filesystem are always reserved for the BPB header block as well as the FAT itself, see chapter «FAT Data Structure» in fatgen103.doc.
In order for us to solve this, we still need to determine the sector span of the root directory entry. For FAT12/16 this can be determined like this:
first_data_sector = ((root_entries * directory_entry_size) +
(bytes_per_sector - 1)) // bytes_per_sector
The directory entry size is always 32 bytes as per specification (see chapter «FAT Directory Structure» in fatgen103.doc), every other value is known by now:
first_data_sector = ((512*32)+(512-1)) // 512 → 32
data_sector = (660-2)*64+(6+(2*233)+32) → 42616
I am working on rocksdb,but unable to get an option which can tell me the maximum limit of size file inside a level ? And if once it reaches that maximum size how files gets split in RocksDB?
The option you are looking for is target_file_size_base and target_file_size_multiplier.
target_file_size_base - configures the size of SST files in level-1.
target_file_size_multiplier - configures the size of SST files in further levels.
For eg : If target_file_size_base is set to 2MB and target_file_size_multiplier is 10,
Level-1 SST files will be 2MB,
Level-2 SST files will be 20MB,
Level-3 SST files will be 200MB and so on..
You can also configure the number of such files in each level using,
max_bytes_for_level_base and max_bytes_for_level_multiplier.
For eg : If max_bytes_for_level_base = 200MB and target_file_size_base = 2MB, then Level-1 will contain 100 files of 2MB each
You can check for these options in options.h and advanced_options.h files.
if once it reaches that maximum size how files gets split in RocksDB
During compaction/flush, the files are created with configured size. If there are more files than the configured number, compaction gets triggered and the files are pushed to higher levels
Trying to import Divi layouts (.json files)
Getting this error:
This file cannot be imported. It may be caused by file_uploads being
disabled in your php.ini. It may also be caused by post_max_size or/and
upload_max_filesize being smaller than file selected. Please increase
it or transfer more substantial data at the time.
This is not the case, however as I don't have a limit on either and I can upload anywhere else within my WP installation.
Does anyone have any idea what else would cause this error?
My response pertains to Divi Theme Version 3.0.46
I had the same problem, and what follows is how I fixed it.
In my case the error is being generated from the Divi Builder portability.js file, line 464:
var fileSize = Math.ceil( ( data.file.size / ( 1024 * 1024 ) ).toFixed( 2 ) ),
formData = new FormData();
// Max size set on server is exceeded.
if ( fileSize >= $this.postMaxSize || fileSize >= $this.uploadMaxSize ) {
etCore.modalContent( '<p>' + $this.text.maxSizeExceeded + '</p>', false, true, '#' + $this.instance( '.ui-tabs-panel:visible' ).attr( 'id' )\
);
$this.enableActions();
return;
}
The thing to note here is, this script is rounding the max upload sizes to whole numbers of MB.
So my max file size for this site was 2MB, and my file is 1,495,679 bytes, which the script turned into:
if 2>=2 {
// throw an error
}
So it seems, the solution is to make both your php upload max size and max post size at least 1MB greater than the file you are trying to upload.
The Elegant Themes people have a lengthy post on this:
https://www.elegantthemes.com/blog/tips-tricks/is-the-wordpress-upload-limit-giving-you-trouble-heres-how-to-change-it
This is as simple as setting this in my php.ini.
; TO have a 31.4MB file upload into Divi, these must be at least 32MB.
post_max_size = 32M
upload_max_filesize = 32M
The final thing I want to say about this as since this error is generated by javascript in the browser, you must:
change your php.ini
restart your webserver [at least I needed to w/ Apache]
refresh the page, as the limits are cached in the browser, not the result of any sort of ajax call, etc.
I had the same issue.I googled and found the solution below.(Apology for not having a proper explanation!)
Solution:
Create a new file php.ini with the following text & save in website's root directory and it's done.
file_uploads = On
upload_max_filesize = 100M
post_max_size = 100M
I have a binary file abc.bin that is 512 bytes long, and I need to generate 1M (1024 x 1024 = 1048576) byte file by appending 0's (0x00) to the abc.bin. How can I do that with dd utility?
For example, abc.bin has 512 bytes of 0x01 ("11 ... 11"), and I need to have a helloos.bin that is 1048576 bytes ("11 ... 11000 ... 000"); the 0 is not '0', but 0x00, and the number of 0x00 is 1048576 - 512.
You can tell dd to seek to the 1M position in the file, which has the effect of making its size at least 1M:
dd if=/dev/null of=abc.bin obs=1M seek=1
If you want to ensure that dd only extends, never truncates the file, add conv=notrunc:
dd if=/dev/null of=abc.bin obs=1M seek=1 conv=notrunc
If you're on a system with GNU coreutils (like, just about any Linux system), you can use the truncate command instead of dd:
truncate --size=1M abc.bin
If you want to be sure the file is only extended, never truncated:
truncate --size=\>1M abc.bin
I'm assuming you actually mean to allocate 1M of zeroes on the disk, not just have a file whose reported length is 1MiB and reads as zeroes.
dd if=/dev/zero count=2047 bs=512 >> abc.bin
This method also works:
Create a 1M file with 0(0x00)s - dd if=/dev/zero of=helloos.bin bs=512 count=2048
Write the abc on the created file - dd of=helloos.bin conv=notrunc if=abc.bin
Without the conv=notrunc option, I have only 512 byte file. I also can use seek=N to control the start position by skipping N blocks.
I believe my rsync is transferring the entire file each time instead of using its algorithm and only transferring changes. Why is this?
I have a text file called rsynctest. Even if I delete only a single character from the text file on the server end, it appears to be transferring the entire file. The rsync stats show: Total transferred file size is 2.55G and the file size is 2.4G so I believe it transferred the entire file.
Here is the output
/usr/bin/rsync -avrh --progress --compress --stats rsynctest x.x.x.x:/rsynctest
sending incremental file list
test
2.55G 100% 27.56MB/s 0:01:28 (xfer#1, to-check=0/1)
Number of files: 1
Number of files transferred: 1
Total file size: 2.55G bytes
Total transferred file size: 2.55G bytes
Literal data: 50.53K bytes
Matched data: 2.55G bytes
File list size: 39
File list generation time: 0.001 seconds
File list transfer time: 0.000 seconds
Total bytes sent: 693
Total bytes received: 404.38K
sent 693 bytes received 404.38K bytes 2.54K bytes/sec
total size is 2.55G speedup is 6305.64
It's not actually transferring the whole file. Look at the "Total bytes sent" and "Total bytes received" lines. It's only transferring the checksums of each block of N bytes (where N can vary), and when a given block's checksums turn out identical, that block isn't transferred. But since the file size has changed, it has to check the whole file for differences. And that's what you're seeing in the progress bar: rsync checking the whole file for differences. (Note also the speed of 27.56MB/s -- I doubt your Internet connection could actually maintain a quarter of a hundred megabytes per second transfer speed. Though if it can, more power to you.)