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Duplicate of: Is there an upper limit on .txt file size?
What is the limit to how much you can write to a text file? Any help would be appreciated.
There is no limit, other than the size of your disk, and your file system limitations on a file.
For example, file size limits:
NTFS: 16 TiB - 64 KiB
Ext4: 16 TBs
FAT32: 4GB - 1
On disk, there is no difference between a text file and any other type of file. They all just store bytes of data.
The only conceptual difference when writing to a binary file and a text file is that when a write operation is performed on a text file, a \n character may be replaced with a \r\n character, or some other line ending character(s).
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Reading the specs for BITMAPFILEHEADER structure says bfSize is the number of bytes in the file.
But when I look at a .bmp file here on my drive it's actually 2 bytes smaller than the file size? Is that just a mistake or does it not count the bfType ? I've seen other examples where it matches the size?
Running the following command in lldb debugger in Xcode
memory read pArr --outfile ~/pArr.dump --count 5081160 --force
produces a file of size around 25MB, instead of the expected 5MB. And it's not exactly 5 times larger than the requested size, just close to it.
Am I doing something wrong, or may it be a problem with lldb?
A typical memory read, not dumping to file, writes a hex dump. That is, it's not writing the raw bytes from memory, it's formatting them to a human-readable representation. Have you looked at your file? I suspect that's what you'll find, in which case it's obvious why it's much larger than the number of bytes dumped. Each byte of memory is represented by several characters (bytes) in the output representation.
There's a -b/--binary option to memory read that may do what you are apparently expecting.
When viewing details of a file using Finder, different values are shown for how much space the file occupies. For example, a file takes up 28.8KB of RAM but, 33KB of the disk. Anyone know the explanation?
Disk space is allocated in blocks. Meaning, in multiples of a "block size".
For example, on my system a 1 byte file is 4096 bytes on disk.
That's 1 byte of content & 4095 bytes of unused space.
what happens when i open a 100 MB file, and insert 1 byte somewhere near the beginning, then save it? does the Linux kernel literally shift everything back 1 byte (thus altering every page), & then re-saves every byte after the insertion? that seems highly inefficient!
or i suppose the kernel could insert a 1-byte page just to hold this insertion, but i've never heard of that happening. i thought all pages had to be a standard size (e.g., 4 KB or 4 MB but not 1 byte)
i have checked in numerous linux/OS bks (bovet/cesati, kerrisk, tanenbaum), & have played around with the kernel code a bit, and can't seem to figure this out.
The answer is that OSes don't typically allow you to insert an arbitrary number of bytes at an arbitrary position within a file. Your analysis shows why - it just isn't an efficient operation on the typical implementation of a file.
Normally you can only add or remove bytes at the end of a file.
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I am in a doubt whether this is a right place for this question..
I want to know if windows 7 or xp has any limit on no. of files within particular folder?
There's no practical limit on the combined sizes of all the files in a folder, though there may be limits on the number of files in a folder. More importantly, there are limits on individual file size that depend on what filesystem you're using on your hard disk. (The "filesystem" is nothing more than the specification of exactly how files are store on disk.)
Let's break this down by file system:
FAT aka FAT16
FAT, for File Allocation Table, is the successor to the original FAT12 filesystem that shipped with MS-DOS many, many years ago.
Maximum disk size: 4 gigabytes
Maximum file size: 4 gigabytes
Maximum number of files on disk: 65,517
Maximum number of files in a single folder: 512 (if I recall correctly, the root folder "/" had a lower limit of 128).
FAT32
"There's no practical limit on the combined sizes of all the files in a folder, though there may be limits on the number of files in a folder."FAT32 was introduced to overcome some of the limitations of FAT16.
Maximum disk size: 2 terabytes
Maximum file size: 4 gigabytes
Maximum number of files on disk: 268,435,437
Maximum number of files in a single folder: 65,534
NTFS
NTFS, or "New Technology File System" introduced with Windows NT, is a completely redesigned file system.
Maximum disk size: 256 terabytes
Maximum file size: 256 terabytes
Maximum number of files on disk: 4,294,967,295
Maximum number of files in a single folder: 4,294,967,295
Note that when I say "disk" above, I'm really talking about "logical" disks, not necessarily physical. No one makes a 256 terabyte disk drive, but using NTFS you can treat an array of disk drives as a single logical disk. Presumably if you have enough of them, you can build a huge logical drive.
Also note that the NTFS's 256 terabyte limitation may well simply be an implementation restriction - I've read that the NTFS format can support disks up to 16 exabytes (16 times 1,152,921,504,606,846,976 bytes).
Source: http://ask-leo.com/is_there_a_limit_to_what_a_single_folder_or_directory_can_hold.html
According to this source, there's not limit per folder. Well, the limit is the same number of files you can store in the volume (NTFS).
Edit: Microsoft link, as pointed in Serverfault.