From the manual...
[-d exdir]
An optional directory to which to extract files. By default, all files and subdirectories are recreated in the current directory; the -d option allows extraction in an arbitrary directory (always assuming one has permission to write to the directory). This option need not appear at the end of the command line; it is also accepted before the zipfile specification (with the normal options), immediately after the zipfile specification, or between the file(s) and the -x option. The option and directory may be concatenated without any white space between them,
but note that this may cause normal shell behavior to be suppressed. In particular, -d ~
(tilde) is expanded by Unix C shells into the name of the user's home directory, but -d~
is treated as a literal subdirectory ~
of the current directory.
So...
unzip -d new_dir zipfile.zip
This creates a directory, new_dir, and extracts the archive within it, which avoids the potential mess every time even without looking first. It is also very useful to look at man unzip
. More help for manual pages.
When searching for a single file in a large archive, it uses method 1, which you can see using strace
:
open("dataset.zip", O_RDONLY) = 3
ioctl(1, TIOCGWINSZ, 0x7fff9a895920) = -1 ENOTTY (Inappropriate ioctl for device)
write(1, "Archive: dataset.zip\n", 22Archive: dataset.zip
) = 22
lseek(3, 943718400, SEEK_SET) = 943718400
read(3, "\340P\356(s\342\306\205\201\27\360U[\250/2\207\346<\252+u\234\225\1[<\2310E\342\274"..., 4522) = 4522
lseek(3, 943722880, SEEK_SET) = 943722880
read(3, "\3\f\225P\\ux\v\0\1\4\350\3\0\0\4\350\3\0\0", 20) = 20
lseek(3, 943718400, SEEK_SET) = 943718400
read(3, "\340P\356(s\342\306\205\201\27\360U[\250/2\207\346<\252+u\234\225\1[<\2310E\342\274"..., 8192) = 4522
lseek(3, 849346560, SEEK_SET) = 849346560
read(3, "D\262nv\210\343\240C\24\227\344\367q\300\223\231\306\330\275\266\213\276M\7I'&35\2\234J"..., 8192) = 8192
stat("rand-28.txt", 0x559f43e0a550) = -1 ENOENT (No such file or directory)
lstat("rand-28.txt", 0x559f43e0a550) = -1 ENOENT (No such file or directory)
stat("rand-28.txt", 0x559f43e0a550) = -1 ENOENT (No such file or directory)
lstat("rand-28.txt", 0x559f43e0a550) = -1 ENOENT (No such file or directory)
open("rand-28.txt", O_RDWR|O_CREAT|O_TRUNC, 0666) = 4
ioctl(1, TIOCGWINSZ, 0x7fff9a895790) = -1 ENOTTY (Inappropriate ioctl for device)
write(1, " extracting: rand-28.txt "..., 37 extracting: rand-28.txt ) = 37
read(3, "\275\3279Y\206\223\217}\355W%:\220YNT\0\257\260z^\361T\242\2\370\21\336\372+\306\310"..., 8192) = 8192
unzip
opens dataset.zip
, seeks to the end, then seeks to the start of the requested file in the archive (rand-28.txt
, at offset 849346560) and reads from there.
The central directory is found by scanning the last 65557 bytes of the archive; see the code starting here:
/*---------------------------------------------------------------------------
Find and process the end-of-central-directory header. UnZip need only
check last 65557 bytes of zipfile: comment may be up to 65535, end-of-
central-directory record is 18 bytes, and signature itself is 4 bytes;
add some to allow for appended garbage. Since ZipInfo is often used as
a debugging tool, search the whole zipfile if zipinfo_mode is true.
---------------------------------------------------------------------------*/
Best Answer
My version of
unzip
has a-j
option to not create any directory.So
Will extract all the files into the current directory without restoring the directory structure stored in the
zip
file.If you want to only remove one level of directories from the archive, (extract
myarchive/dir/file
asdir/file
, notfile
), you could usebsdtar
(which does supportszip
files in addition totar
files) instead and its-s
option.