5 ms·

Back in the day, one of the selling points of the RAR format was that it could partition large files into multiple archives, so you could upload it in chunks, o

Back in the day, one of the selling points of the RAR format was that it could partition large files into multiple archives, so you could upload it in chunks, or copy it to multiple flash drives or CDs. Have other archive formats caught up with this feature?

marcodiego 6y ago
I don't know, but I think such feature would be way less valuable today.
- sitzkrieg 6y ago
  true but its still used heavily on eg usenet binaries, and nzb tools run the 100s of unrar for you not unlike the gui
- tener 6y ago
  There are niche uses, mostly with some forms of file sharing with limited file size. For example email attachments, but not only this.
scaladev 6y ago
Caught up? tar has had this for a few billion years at least: $ tar cazf - file1 file2 | split -b 700m - out.tgz 7zip also natively supports splitting for as long as I can remember.
- progval 6y ago
  You didn't address this: > or copy it to multiple flash drives or CDs How would you use 'split' without either dumping the whole archive on disk or pluggin all drives at the same time?
  - epmos 6y ago
    tar was designed for tape, so you can specify a volume size for the output and it will break it's output into segments of that size. Using split isn't required. The options in gnu tar are -L and -M for specifying tape length (in KB) and creating multi-volume archives. The -L version is handy as it can prompt you to change the "tape". It has built-in tape handling as well, if you are using a real tape that can be controlled via mt. Apparently (just checked info) it supports an arbitrary command to execute at the end of each archive. That would be handy for burning CDs, though I don't remember that feature from when I used floppies or QIC-40 to move files from one machine to another. Around 1991-ish I would use these options to put archives onto stacks of floppy disks. The floppies didn't have a filesystem, just blocks of tar archive. In the days of 9600 bps modems, this was often the fastest way to move stuff to another machine. I had an often-reused stack of 3.5in HD floppies labeled with numbers for this purpose.
tener 6y ago
7zip for sure has. It actually supports it for more than just 7z format.
agurk 6y ago
I was about to reply a little snarkily that I was doing this with zip archives on floppy disks back in the 90s. I thought I might as well check my facts before posting, and it looks like that was a part of WinZip that was not part of the standard. In 2015 ISO published a standard pertaining to zip archives, and one of the specifications was (from Wikipedia): Archives may not span multiple volumes or be segmented. There are also multiple forum posts when you search for multipart zip archives of Linux users asking how to decompress them, suggesting that this is only WinZip behaviour and not common to the zip standard.
- diggernet 6y ago
  I had the same reaction, but checked a different set of facts than you did. PKZIP 2.04g (which at the time was the standard) supported split archives, in January 1993. WinZip added support in version 8.1, in 2001. Edit: I just found the page where you got your quote. Looks like ISO was deliberately defining a subset of ZIP.
- marcodiego 6y ago
  I remember people using arj exactly because of that feature. Compression with arj was worse than zip but people used it because you could divide an arj archive in floppies. At the time, rar could do it too, but it only got popular later.
fogihujy 6y ago
ARJ had that feature and it predates RAR by a few years.
ReactiveJelly 6y ago
Isn't that just the same as splitting any file into multiple chunks? Why does the archive format have to know about it? For non-solid compression? Otherwise, any file can be split up and re-combined at the other end, unless you don't have the hard drive space to recombine it. The only way I've seen RAR used in torrents is to package everything into one big file, and since they're usually video or audio that already has lossy compression, and since I may want to prioritize or skip certain files, it's both pointless and annoying.
eps 6y ago
Multiple floppies! Floppies... "flash drives"... pfft.

marcodiego 6y ago

I don't know, but I think such feature would be way less valuable today.

sitzkrieg 6y ago
true but its still used heavily on eg usenet binaries, and nzb tools run the 100s of unrar for you not unlike the gui
tener 6y ago
There are niche uses, mostly with some forms of file sharing with limited file size. For example email attachments, but not only this.

scaladev 6y ago

Caught up? tar has had this for a few billion years at least: $ tar cazf - file1 file2 | split -b 700m - out.tgz 7zip also natively supports splitting for as long as I can remember.

progval 6y ago
You didn't address this: > or copy it to multiple flash drives or CDs How would you use 'split' without either dumping the whole archive on disk or pluggin all drives at the same time?
- epmos 6y ago
  tar was designed for tape, so you can specify a volume size for the output and it will break it's output into segments of that size. Using split isn't required. The options in gnu tar are -L and -M for specifying tape length (in KB) and creating multi-volume archives. The -L version is handy as it can prompt you to change the "tape". It has built-in tape handling as well, if you are using a real tape that can be controlled via mt. Apparently (just checked info) it supports an arbitrary command to execute at the end of each archive. That would be handy for burning CDs, though I don't remember that feature from when I used floppies or QIC-40 to move files from one machine to another. Around 1991-ish I would use these options to put archives onto stacks of floppy disks. The floppies didn't have a filesystem, just blocks of tar archive. In the days of 9600 bps modems, this was often the fastest way to move stuff to another machine. I had an often-reused stack of 3.5in HD floppies labeled with numbers for this purpose.

tener 6y ago

7zip for sure has. It actually supports it for more than just 7z format.

agurk 6y ago

I was about to reply a little snarkily that I was doing this with zip archives on floppy disks back in the 90s. I thought I might as well check my facts before posting, and it looks like that was a part of WinZip that was not part of the standard. In 2015 ISO published a standard pertaining to zip archives, and one of the specifications was (from Wikipedia): Archives may not span multiple volumes or be segmented. There are also multiple forum posts when you search for multipart zip archives of Linux users asking how to decompress them, suggesting that this is only WinZip behaviour and not common to the zip standard.

diggernet 6y ago
I had the same reaction, but checked a different set of facts than you did. PKZIP 2.04g (which at the time was the standard) supported split archives, in January 1993. WinZip added support in version 8.1, in 2001. Edit: I just found the page where you got your quote. Looks like ISO was deliberately defining a subset of ZIP.
marcodiego 6y ago
I remember people using arj exactly because of that feature. Compression with arj was worse than zip but people used it because you could divide an arj archive in floppies. At the time, rar could do it too, but it only got popular later.

fogihujy 6y ago

ARJ had that feature and it predates RAR by a few years.

ReactiveJelly 6y ago

Isn't that just the same as splitting any file into multiple chunks? Why does the archive format have to know about it? For non-solid compression? Otherwise, any file can be split up and re-combined at the other end, unless you don't have the hard drive space to recombine it. The only way I've seen RAR used in torrents is to package everything into one big file, and since they're usually video or audio that already has lossy compression, and since I may want to prioritize or skip certain files, it's both pointless and annoying.

eps 6y ago

Multiple floppies! Floppies... "flash drives"... pfft.