GNU Core Utilities are the GNU project's implementation of the core command-line tools of a POSIX system, including tools like ls, cp, mv, rm, etc.

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3
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2answers
61 views

Wrap and indent text using coreutils

Short version I would like to create a tabular display of multiline text, similar to the following: all Build all targets document Create documentation of source files in the subfolders ...
1
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1answer
33 views

What metadata of a file does cp preserve by default?

By default, what file metadata does cp preserve, and what file metadata not? For example, if I am correct, the mtime is changed, the access list is preserved, and I would to know about the other ...
1
vote
1answer
147 views

Seq performance hit when specifying a format string

Running seq (GNU coreutils 8.21) without specifying a format string runs extremely quickly compared with any possible format I tried: $ time seq 1e8 > /dev/null seq 1e8 > /dev/null 0.68s ...
0
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0answers
18 views

How to replace GNU core utilities with Busybox in a Linux system [duplicate]

Is it possible/safe to replace the GNU coreutils with Busybox in a GNU/Linux system? What else (binutils, bash) could be replaced? How much free disk space would I get with that? If possible, give ...
0
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1answer
14 views

custom sysconfdir for coreutils

I compiled coreutils with --sysconfdir=/test/etc instead of default /etc, moved /etc/group to /test/etc/group, and chgrp failed with chgrp: invalid group: $groupname. How can I fix that and ...
4
votes
4answers
532 views

Why can't mv deal with existence of same-name directory in destination?

mv can't move a directory to a destination with a same-name directory: $ mv fortran/ imperative_PLs/ mv: cannot move ‘fortran/’ to ‘imperative_PLs/fortran’: Directory not empty Why does mv not ...
22
votes
4answers
2k views

What is the use of the -f option for `touch`?

From man touch: -f (ignored) But I don't get what is meant by ignored. I've tried following: $ ls -l file -rw-rw-r-- 1 pandya pandya 0 Mar 20 16:17 file $ touch -f file $ ls -l file ...
3
votes
1answer
81 views

How does unexpand command really work?

I've already read some explananations about unexpand, but either I don't understand, or is not working as expected. Let's consider the following example: [root@hope log]# echo "A12345678B" | tr ...
0
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2answers
79 views

Is Chromium OS a GNU/Linux distro?

I want to ask, if Chromium OS is a GNU/Linux distribution or is it a non-GNU Linux-based operating system like Android, webOS or Syllable Server. Does Chromium OS use GNU C Library, GNU coreutils ...
1
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0answers
36 views

Conditional expressions in shell: What are the differences between [ vs [[ [duplicate]

I just wondered about some people writing if [[ <expr> ]]; then ... in answers here when I out of habit would use if [ <expr> ]; then ... Doing a quick research reveals that [[ ]] ...
4
votes
1answer
164 views

Debian wheezy updates broke tr command [closed]

After I updated the following packages yesterday in debian wheezy, tr command stop working. Start-Date: 2016-02-16 23:10:06 Commandline: apt-get dist-upgrade Upgrade: libkrb5-3:amd64 ...
41
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3answers
5k views

How does `yes` write to file so quickly?

Let me give an example: $ timeout 1 yes "GNU" > file1 $ wc -l file1 11504640 file1 $ for ((sec0=`date +%S`;sec<=$(($sec0+5));sec=`date +%S`)); do echo "GNU" >> file2; done $ wc -l ...
4
votes
2answers
97 views

How to find out if a file on btrfs is copy-on-write?

I know that cp has a --reflink option to control full copies vs. copy-on-write "copies". On btrfs, can I use ls (or some other command) to find out whether a file shares (in a copy-on-write senses) ...
0
votes
0answers
30 views

what's the use of yes (coreutils)? [duplicate]

I notice my shell has a util named "yes" It just output a infinite "y" string line by line What's the use of this "core util" of "yes" ? Usage: yes [STRING]... or: yes OPTION Repeatedly output a ...
3
votes
3answers
52 views

Symmetric Difference Pipe?

I have a command that produces a lists of strings followed by newlines, a, and a file containing a list of strings followed by newlines, b.txt. I need a command that calculates the symmetric ...
0
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2answers
42 views

Unix equivalent of `du -sb` to get summarized size in bytes

On Linux using GNU du to calculate the size of directory recursively in bytes I can run: du -sb /etc What is equivalent syntax for BSD du based on the fact that -b parameter is not available?
0
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0answers
76 views

LFS error - Coreutils (step 6.29)

As succinctly as I can put, I've gotten all the way to 6.29 in the book (Coreutils) and I seem to be receiving the following error when running the "make" command. Full output is as follows: ...
4
votes
1answer
76 views

Why does a '.' work in chown?

Why does GNU chown user.group work? The docs say nothing of the syntax being supported. Is there a juicy story behind it?
0
votes
1answer
67 views

Error in 'date -d' command

Hmmm... Right now (Sat Oct 24 00:36:56 CDT 2015) on my Arch Linux system there appears to be a problem with the date command: $ date -d "+8 days" "+%A %d %B %Y" Sunday 01 November 2015 $ date -d "+9 ...
4
votes
1answer
119 views

mv overwrites read-only file without prompting

The GNU Coreutils manual for mv says: If a destination file exists but is normally unwritable, standard input is a terminal, and the -f or --force option is not given, mv prompts the user for ...
4
votes
1answer
425 views

`set -e` and `grep` idiom for preventing premature exit from shell script when pattern not found

Help required - in the context of shell scripting on a GNU/LINUX bash: I always use set -e. Often, I would like to grep and do not always want the script to terminate execution if grep has an exit ...
5
votes
1answer
104 views

When is next Monday?

On my home computer (Xubuntu 14.04), I have zev@home:~$ date +%F 2015-10-05 zev@home:~$ date +%F -d "next Monday" 2015-10-12 whereas at work (Red Hat 5.11), I have zev@work:~$ date +%F ...
6
votes
1answer
152 views

How can I delete a file named “--append”? [duplicate]

By mistake I have created a file named : --append. How do I delete it? Simply entering the usual command, rm -f --append, doesn't work.
0
votes
1answer
60 views

Strange cut behavior

I'm using cut (GNU coreutils) 8.24. The command: echo "TEST=test" | cut -d"=" -f2- outputs Ttest. I don't think this is the intended behavior. Am I using it wrong or is there something wrong with my ...
25
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2answers
1k views

Why does ln -s accept a single argument

> cd /tmp > ln -s foo > ls -alhF /tmp lrwxrwxrwx 1 user user 3 Jul 29 14:00 foo -> foo Is this a bug in ln or is there a use case for symlinking a file to itself? This is with ...
5
votes
1answer
162 views

Is there a command line tool to manage unix signals?

Is there a command runner like env, nice, nohup, etc., that can run a program with modified signals? In my case, I need something to reset SIGINT to SIG_DFL. Why do I need this? Because ...
2
votes
1answer
286 views

sudo ls not showing hidden files on Linux

Today I discovered that sudo ls shows hidden files (that is, those that have names starting with .) on OS X. This surprised me so much that I asked a question about this behaviour, which I still find ...
6
votes
1answer
2k views

How does the “1 month ago” option in date command work?

I'm not sure if this gets the past date within the current day or if it only takes 30 or 31 days to it. e.g. If the current date is March 28th, 1 month ago must be February 28th, but what happen ...
4
votes
2answers
353 views

change file size format when using stat

The formatting character %s makes stat print the filesize in bytes # stat -c'%A %h %U %G %s %n' /bin/foo -rw-r--r-- 1 root root 45112 /bin/foo ls can be configured to print the byte size number ...
0
votes
1answer
202 views

cp options --no-clobber vs. --update

I want to copy a single file if (and only if) the destination does not exist. The source file changes rarely, maybe once a month. The destination almost never exists. Are there any differences ...
2
votes
1answer
871 views

what are practical uses of stdbuf or nohup?

I have to finish a writeup of a few coreutils commands for a course at the moment, and I can't think of a starting point for a small practical code example that demonstrates the potential uses of ...
0
votes
1answer
171 views

*ls* font differences between files and folders with “--color” option

I have recently switched to urxvt from xterm for better unicode support and it does much better as to the font fallback. However I find an interesting issue: names of files and folders are rendered ...
2
votes
1answer
193 views

How can I cross compile the dd linux tool for arm?

I need to cross-compile a full version of dd because my device only has a busybox one that doesn't support many options. Where do I get the source for it? I've been looking on the kernel repo online ...
2
votes
1answer
186 views

Installed coreutils on CentOS for sort --human-readable flag but it still doesn't work

I'm trying to do du -h | sort -h, but my CentOS 5.7 doesn't have -h flag for sort. So I installed coreutils Updated: coreutils.x86_64 0:5.97-34.el5_8.1 Complete! yet sort still doesn't have ...
2
votes
1answer
64 views

Difference between / and // [duplicate]

On the bash prompt one, three or more slashes (/,///,////, ...) are treated as a single slash, whereas two slashes (//) are left as is: 12:07 $ cd / 12:07 $ pwd / 12:07 $ cd // 12:07 $ pwd // 12:07 $ ...
20
votes
3answers
2k views

Why is coreutils sort slower than Python?

I wrote the following script to test the speed of Python's sort functionality: from sys import stdin, stdout lines = list(stdin) lines.sort() stdout.writelines(lines) I then compared this to the ...
0
votes
0answers
23 views

Set default editor for 'info coreutils' [duplicate]

I'm using Ubuntu 14.04 and have this in my .bash_profile: export EDITOR=/usr/bin/vim export VISUAL=/usr/bin/vim man respects this setting but info always opens in something else, nano or it's own ...
0
votes
1answer
201 views

Why can't my `date` deal with timezones? [duplicate]

I'm having some weird issues with GNU coreutils date v8.4 (CentOS) that aren't occurring in v8.21 (Ubuntu/Mint). On v8.4, I get the following output (I'm in PST): $ date --version | head -n 1 date ...
3
votes
1answer
1k views

Problem with install command to copy a whole directory

So I have a repo with some of my config files and I'm trying to create a makefile to install them in the homedir. The problem I have is that when I run the following command straight in bash install ...
0
votes
2answers
756 views

Permissions for installing coreutils with pkgsrc on NetBSD

I'm trying to install coreutils on NetBSD 6.1.5 using the pkgsrc system. This is on the default install of 6.1.5. The only change made has been to install zsh and set it as my default shell for users ...
2
votes
1answer
98 views

Where is using @ before a date string for seconds since the epoch documented?

GNU date and touch commands (and presumably others) use @date to define a date string as seconds since the epoch. For example: $ TZ=UTC date -d@10 Thu Jan 1 00:00:10 UTC 1970 I was answering a ...
2
votes
3answers
500 views

When was a file last opened?

How do I determine, when a file was last opened? I've looked at man ls (using GNU coreutils 8.22) and I don't see anything about this timestamp.
9
votes
2answers
1k views

sort by hex value

Using coreutils sort, how can I sort numerically by a hexadecimal value (field)? I was expecting something along the lines of sort -k3,3x file_to_sort however, such an x does not exist. Edit: ...
0
votes
2answers
91 views

Where can I view a changelog for the sort command

I need to find sort's version when the -V flag was introduced. But I am finding myself some hard time finding the changelog for this command. Where can I view it?
1
vote
2answers
173 views

numfmt invalid suffix input

I am using numfmt to convert a remote file's Content-Length from bytes to IEC format, i.e. 21M $ curl -sI http://jruby.org.s3.amazonaws.com/downloads/1.7.12/jruby-bin-1.7.12.tar.gz|grep Length|cut ...
1
vote
1answer
77 views

“install” command as script

I'm working on a heavily modified Linux based OS targeted for a really specific environment - easy-to-use NAS systems. It does not provide any GUI, apart from a web interface, but it at least has SSH. ...
8
votes
2answers
2k views

How is the order in which tar works on files determined?

$ touch dir/{{1..8},{a..p}} $ tar cJvf file.tar.xz dir/ dir/ dir/o dir/k dir/b dir/3 dir/1 dir/i dir/7 dir/4 dir/e dir/a dir/g dir/2 dir/d dir/5 dir/8 dir/c dir/n dir/f dir/h dir/6 dir/l dir/m dir/j ...
30
votes
3answers
2k views

What is the `[` program that resides in my system's /bin?

I was recently browsing my Fedora's /bin folder and noticed a binary named [. I did try to search the internet for more information on that, but I couldn't find anything useful. Running it through ...
4
votes
2answers
525 views

What does `du - hb` do?

With du -bh I think I get the apparent size in human readable format: # du -bh 295K ./test However, I would expect the same from du -hb, but I get something else: # du -hb 301926 ./test I ...
5
votes
2answers
6k views

Why is dd using direct slower writing to disk than to a file

I am trying to compare aggregate write rates when writing to a file in a GPFS file system, as compared to writing directly to a disk on a system with Red Hat Enterprise Linux Server release 6.4 ...