When you perform ls in a bash shell, sometimes there are colours to indicate different resource types, and you can enable/control this with the --color argument.
But neither the man page nor Google is providing an answer to the question:
What do these colours indicate by default, and how do I display what the current system uses?
UPDATE:
Thanks everyone for answers so far, however to make it easier to pick a winner, can anyone go a step further and provide a method to output descriptions in the colours they apply to.
Hmmm... my example doesn't work when posted (only when previewed), so if you preview this code it'll show what I mean...
<ul style="list-style:none; background:black; margin:0;padding:0.5em; width:10em">
<li style="color:blue">directory</li>
<li style="color:aqua">symbolic link</li>
<li style="color:#A00000;">*.tar files</li>
<li style="color:white">...</li>
</ul>
Thanks.
The colors are defined by the $LS_COLORS environment variable. Depending on your distro, it is generated automatically when the shell starts, using ~/.dircolors or /etc/DIR_COLORS.
Edit:
To list color meanings, use this script:
eval $(echo "no:global default;fi:normal file;di:directory;ln:symbolic link;pi:named pipe;so:socket;do:door;bd:block device;cd:character device;or:orphan symlink;mi:missing file;su:set uid;sg:set gid;tw:sticky other writable;ow:other writable;st:sticky;ex:executable;"|sed -e 's/:/="/g; s/\;/"\n/g')
{
IFS=:
for i in $LS_COLORS
do
echo -e "\e[${i#*=}m$( x=${i%=*}; [ "${!x}" ] && echo "${!x}" || echo "$x" )\e[m"
done
}
Running the command dircolors -p will print all default colour settings.
See http://linux.about.com/library/cmd/blcmdl1_dircolors.htm.
You should be able to see the list of mappings in /etc/DIR_COLORS. You can override that by creating .dir_colors in your home directory.
Try "man 5 dir_colors" to see how it's set on your system. Mine doesn't have /etc/DIR_COLORS so it must be set somewhere else.
Google for LS_COLORS for some useful links.
Edit: To list the colors, this simple bash script may give an idea:
IFS=:
set $LS_COLORS
for C in $*
do
IFS='='
set $C
echo -e "\033[$2m$1\033[00m"
done
Related
I have a global npm package that provided by a third party to generate a report and send it to server.
in_report generate -date 20221211
And I want to let a group of user to have the ability to check whether the report is generated or not, in order to prevent duplication. Therefore, I want to run a sh script before executing the in_report command.
sh check.sh && in_report generate -date 20221211
But the problem is I don't want to change the command how they generate the report. I can do a patch on their PC (able to change the env path or etc).
Is it possible to run sh check.sh && in_report generate -date 20221211 by running in_report generate -date 20221211?
If this "in_report" is only used for this exact purpose, you can create an alias by putting the following line at the end of the ".bashrc" or ".bash_aliases" file that is used by the people who will need to run in_report :
alias in_report='sh check.sh && in_report'
See https://doc.ubuntu-fr.org/alias for details.
If in_report is to be used in other ways too, this is not the solution. In that case, you may want to call it directly inside check.sh if a certain set of conditions on the parameters are matched. To do that :
alias in_report='sh check.sh'
The content of check.sh :
#!/bin/sh
if [[ $# -eq 3 && "$1" == "generate" && "$2" == "-date" && "$3" == "20"* ]] # Assuming that all you dates must be in the 21st century
then
if [[ some test to check that the report has not been generated yet ]]
then
/full/path/to/the/actual/in_report "$#" # WARNING : be sure that nobody will move the actual in_report to another path
else
echo "This report already exists"
fi
else
/full/path/to/the/actual/in_report "$#"
fi
This sure is not ideal but it should work. But by far the easiest and most reliable solution if applicable would be to ignore the aliasing thing and tell those who will use in_report to run your check.sh instead (with the same parameters as they would put to run in_report), and then you can directly call in_report instead of the /full/path/to/the/actual/in_report.
Sorry if this was not very clear. In that case, feel free to ask.
On most modern Linux distros the easiest would be to place a shell script that defines a function in /etc/profile.d, e.g. /etc/profile.d/my_report with a content of
function in_report() { sh check.sh && /path/to/in_report $*; }
That way it gets automatically placed in peoples environment when they log in.
The /path/to is important so the function doesn't call itself recursively.
A cursory glance through doco for the Mac suggests that you may want to edit /etc/bashrc or /etc/zshrc respectively.
Hello I am trying to translate my .bashrc to fish format almost done, mostly is clear on the documentation but this part is giving me a headache.. is so my gnupg works with my yubikey ssh etc etc..
The fish version is latest 3.0 under Arch GNU/Linux
original on BASH:
# Set SSH to use gpg-agent
unset SSH_AGENT_PID
if [ "${gnupg_SSH_AUTH_SOCK_by:-0}" -ne $$ ]; then
export SSH_AUTH_SOCK="/run/user/$UID/gnupg/S.gpg-agent.ssh"
fi
echo "UPDATESTARTUPTTY" | gpg-connect-agent > /dev/null 2&>1
Mine half converted into fish:
set -e SSH_AGENT_PID
if [ "${gnupg_SSH_AUTH_SOCK_by:-0}" -ne $$ ]
set -x SSH_AUTH_SOCK="/run/user/$UID/gnupg/S.gpg-agent.ssh"
end
echo "UPDATESTARTUPTTY" | gpg-connect-agent > /dev/null 2>&1
so as you see above I have so far converted the stdin and stderror pine and the unset variable with set -e the error I am having is a bit more obscure to me:
~/.config/fish/config.fish (line 33): ${ is not a valid variable in fish.
if [ "${gnupg_SSH_AUTH_SOCK_by:-0}" -ne $$ ]
^
from sourcing file ~/.config/fish/config.fish
called during startup
Any help will be much appreciated,
BTW will be nice a migrate too :) are there any out there?
[edit] ok got this working thanks to the response below, now all my bash environment, profile, bashrc etc is translated to fish and using it solely as my shell 100%
You should not change your login shell until you have a much better understanding of fish syntax and behavior. For example, in fish the equivalent of $$ is %self or $fish_pid depending on which fish version you are using. You should always specify the version of the program you are having problems with.
Assuming you're using fish 2.x that would be written as
if not set -q gnupg_SSH_AUTH_SOCK_by
or test $gnupg_SSH_AUTH_SOCK_by -ne %self
set -gx SSH_AUTH_SOCK "/run/user/$UID/gnupg/S.gpg-agent.ssh"
end
Also, notice that there is no equal-sign between the var name and value in the set -x.
Since ${var:-value} expands to value if $var is empty, you can always replace it by writing your code out the long way:
begin
if test -n "$gnupg_SSH_AUTH_SOCK_by"
set result "$gnupg_SSH_AUTH_SOCK_by"
else
set result 0
end
if [ "$result" -ne %self ]
set -x SSH_AUTH_SOCK "/run/user/$UID/gnupg/S.gpg-agent.ssh"
end
set -e result
end
Note that I don't use (a) endorse, (b) condone the use of, or (c) fail to hold unwarranted prejudices against users of, fish. Thus, my advice is very much suspect, and it's likely that there are considerably better ways to do this.
I had a similar question, related to XDG_* variables.
var1="${XDG_CACHE_HOME:-$HOME/.cache}"/foo
var2="${XDG_CONFIG_HOME:-$HOME/.config}"/foo
var3="${XDG_DATA_HOME:-$HOME/.local/share}"/foo
some-command "$var1" "$var2" ...
What I found as the best alternative is to simply set univeral variables once for the defaults--
set -U XDG_CACHE_HOME ~/.cache
set -U XDG_CONFIG_HOME ~/.config
set -U XDG_DATA_HOME ~/.local/share
Then in fish config file(s) or scripts, simply use "$XDG_CONFIG_HOME"/.... The value of an exported environment variable will override the universal variable if set, otherwise the universal variable is there as a default/fallback. If the universal variable is used, it is not exported to child processes, while an exported environment variable is, which provides the full equivalent to bash|zsh parameter expansion.
I'm working on a bash script that will add users in a batch process. This code goes as follows:
#!/bin/bash
# A script that creates users.
echo "This is a script to create new users on this system."
echo "How many users do you want to add?"
read am
echo " "
for i in {0..$am..1}
do
echo "Enter a username below:"
read usern
sudo useradd $usern
sudo passwd $usern
echo " "
echo "User $am '$usern' added."
done
In this case, I wanted to make 4 users. I went through and entered the username "callum3" and set the password as "1234" for ease of login. Once I input everything (correctly, may I add) the terminal window displays the following.
User 4 'callum3' added.
This shows that my for loop isn't actually working, when I can see nothing wrong with it. I have tried using a while loop with no luck there either.
Am I making a rookie mistake here or is there something deeper going on?
Although I suspected it, for a better understanding on what could be wrong with your script I pasted it in shellcheck.net. That the problem is in the line:
for i in {0..$am..1}
Bash doesn't support variables in brace range expansions. That is, you cannot use a variable in an expression like {..}.
Instead, use seq. With seq $var you get a sequence from 1 (default) to $var:
for i in $(seq "$am")
I feel like I'm missing something in that nobody has suggested an arithmetic for loop:
for ((i=0; i<am; i++)); do
…
done
This has the particular benefit in bash of being both readable and not requiring a subshell.
You can use:
for i in `seq 0 $((am-1))`
do
...
done
Sequence will start from 0 and end at $am-1
Is it possible to output text to a shell window, via bash script, that is user-editable? I essentially want to pre-fill certain information and give the user the ability to edit it if it's wrong.
For instance, if I were to write in a script:
echo -n "Enter your name: Anthony"
while read user_input
do
# do stuff with $user_input
done
How can I allow the user to inline edit the word Anthony only (aka, don't allow backspacing past the A in Anthony), and how can I store the value into a variable once the RETURN key is pressed?
EDIT
I'm looking for something similar to the -i option of read (see answer posted here), but this is only available on bash 4+. Is there an alternative for bash 3?
I needed similar setup recently so what I did was
$ cat a.sh
function input {
python -c '
import sys,readline
readline.set_startup_hook(lambda: readline.insert_text(sys.argv[2]))
sys.stderr.write(raw_input(sys.argv[1]))
' "$#" 3>&1 1>&2 2>&3
}
A=$( input 'question: ' default )
echo "A='$A'"
$ ./a.sh
question: default
A='default'
Well, it's not actually bash, but it made the job done.
If I run a bash script as
./myscript.sh zone=A build=release
Is there someway I can read the arguments based on the parameters instead of using $1, $2?
No. Unix shells are an ancient technology, hash maps were known at the time but not "en vogue." They needed more than 1 byte to implement so the professionals didn't want to use such a wasteful technology.
What else can you do? The usual solution is getopt(1).
An alternative is to write all options to a file and source that:
echo "$#" | tr ' ' '\n' > options
. ./options
echo "zone=${zone}"
Hope this is what you are asking for:
A="try"
try="something"
echo ${!A}
> something
This is close to what you want.
set -k
./myscript.sh zone=A build=release
will behave the same as
zone=A build=release ./myscript.sh
that is, myscript.sh will see zone and build with the given values in its environment.