Tagged Questions
5
votes
4answers
149 views
Hybrid code in shell scripts. Sharing variables
This answer discusses how to run a multi-line Python snippet from the command line in a terminal. I noticed that the answer works great within shell scripts, even with nested indentation, which is ...
4
votes
2answers
98 views
Wrap command in the prompt
Is it possible to insert a separator after the command in a prompt? This is an example:
~/Desktop: ls -al
-------------------------------------
total 80
drwx------+ 6 eddie staff 204B Apr 29 ...
-4
votes
1answer
113 views
zsh: Is it worth the switch from bash? Is it the time? [closed]
I have been a bash user for years now. However, I find that zsh is increasingly gaining momentum. I came up with the following questions:
Is zsh really becoming that popular? Will it compete with ...
0
votes
2answers
50 views
Command in a variable [duplicate]
I am trying to run a statement where the name of the command is in a variable. For example:
my_command='/path/to/some/command'
$my_command -f foo -b bar -s something else
But the above does not ...
2
votes
3answers
89 views
Treatment of backslashes across shells
How do echo and printf treat backslashes in zsh, bash and other shells?
Under zsh I get the following behavior:
$ echo "foo\bar\baz"
foaaz
$ echo "foo\\bar\\baz"
foaaz
$ echo 'foo\bar\baz'
foaaz
$ ...
5
votes
4answers
237 views
Is it recommended to use zsh instead of bash scripts?
Can I assume that enough people have zsh installed to run scripts with a
#!/usr/bin/env zsh
as shebang?
Or will this make my scripts un-runnable on too many systems?
Clarification: I’m interested ...
6
votes
2answers
102 views
When is double-quoting necessary?
The old advice used to be to double-quote any expression involving a $VARIABLE, at least if one wanted it to be interpreted by the shell as one single item, otherwise, any spaces in the content of ...
3
votes
3answers
100 views
Delete all but largest file of specific type
I am trying to organise the album art in my music collection so that only one image is assigned to each folder.
My directory structure currently looks like:
/path/to/music/Album Name/
...
2
votes
1answer
61 views
How to print apparently hidden environment variables?
Environment variables can be shown with env; but, some are not shown. For example...
echo $EUID might produce as result of 1000 yet
env | grep EUID produces no result.
What is this type of variable? ...
3
votes
4answers
98 views
Double and triple substitution in bash and zsh
Follow-up to the background part in this question.
In bash I can use {!FOO} for double substitution, in zsh ${(P)FOO}. In both, the old-school (hack-y) eval \$$FOO works.
So, the smartest and most ...
2
votes
2answers
57 views
${!FOO} and zsh
${!FOO} performs a double substitution in bash, meaning it takes the (string) value of FOO and uses it as a variable name.
zsh doesn’t support this feature.
Is there a way to make this work the same ...
5
votes
2answers
86 views
[ vs [[ : which one to use in bash scripts? [duplicate]
The zsh man page, in its section on test (aka [), explicitly advises against using it at all, and urges readers to use [[ whenever possible.
The relevant section states:
The command attempts to ...
1
vote
1answer
49 views
How to more easily specify tasks for batch, using command prefix tool?
The tool batch that comes with the atd daemon is pretty useful in principle, running commands only when the system utilisation falls below a certain level (by default, 1.5). However, using it (and ...
1
vote
2answers
111 views
OS X setting environment variables
I have OSX 10.8.2 with ZSH as my shell and iTerm as a terminal (don't know if the last thing is relevant). I have to mention that I'm relatively new to OSX.
I'm trying to set up some environment ...
0
votes
2answers
102 views
Comparison of shells? [closed]
Do shells have any actual advantages or disadvantages? They can all run any binary, they all support pipes and > (output to file). Why would one choose bash over sh, or sh over ksh, etc? Why does ...
4
votes
3answers
107 views
Can any shell do argument-level interactive search?
Sometimes I need to reuse certain long arguments like paths.
If I use history search (CTRL+R), I may find some command that contains the path, but I still need to delete anything else in the old ...
0
votes
2answers
128 views
Proper place to put shell prompt(PS1) when use sh/bash/zsh together
I'm using dash(sh) or bash or zsh. If possible, I would prefer to put in common place.
I want to put proper PS1 settings when I interactive with shell, so these situation should be considered
login ...
3
votes
4answers
111 views
Delete backward until met a char, like alt + bksp
Say my current line was:
/tmp/path/to/file:123
Now I'm at the end of this line, now I want to delete :123 by pressing some key combination, was that possible? (colon was merely mentioned as an ...
2
votes
1answer
95 views
Zsh style arrays with Bash
Does Bash have a way to access arrays similar to Zsh, something like
$ foo=(dog cat mouse)
$ echo $foo[1]
cat
instead of
$ echo ${foo[1]}
perhaps using some shopt setting?
2
votes
1answer
563 views
What happened to ~ when updating oh-my-zsh?
Not sure what changed the meaning of the home path ~ in my zsh.
So when I do cd ~ , I dont cd into my home but it gives me an error that /Users/carlos does not exist.
How can I reset ~ to refer to ...
3
votes
5answers
536 views
Output multiple files from a single grep?
I'm not very experienced in shell scripting, but I'm trying to understand how to grep for a pattern and for each file where there is a match write a file to disk that contains the matched line from ...
3
votes
3answers
472 views
What's the right way to sort a associated array in bash or zsh?
I'm wondering how should I sort the associated array in bash? I tried the manual, but seems nothing related to sort.
The current solution is echo everything out, and use external program i.e key ...
3
votes
4answers
120 views
Editing output of command as a new command
I have a script that outputs a string that I would like to edit and then run as a command.
For example, I am using
cat ... | xsel -p
And then I want to edit the output of `xsel -op´ and run the ...
3
votes
3answers
342 views
Using OR patterns in shell wildcards
Contents of my dir are
$ ls -lrt
total 0
-rw-r--r-- 1 user1 admin 19 Oct 8 12:31 night.txt
-rw-r--r-- 1 user1 admin 19 Oct 8 12:31 noon.txt
-rw-r--r-- 1 user1 admin 38 Oct 8 12:31 day.txt
I ...
2
votes
3answers
907 views
Bash Auto-Completion feature for SSHing into Different Hosts
I have big list of servers which I normally ssh to all the time. Is there any way using bash or zsh so that I can keep the list of hostname and bash auto-completion goes through the file and gives me ...
4
votes
2answers
165 views
Inhibit Variable Expansion in Paths
How do I prevent Zshell (and Bash I assume) from expanding environment variables in paths be completed as shown in the following example:
$PREFIX/alt/li
should expand to
$PREFIX/alt/lib
and not ...
0
votes
0answers
67 views
/long/path/to/{multiple, files} syntax? [duplicate]
Possible Duplicate:
Quick way to include a directory path when calling mv?
Is there any way in bash to type a path once, and then reference several files at once?
Here's what I do now:
...
4
votes
3answers
499 views
How to set bash to run *.exe with mono?
Without any DE or even X, I want to use ./my.exe to run mono my.exe, like it works with python scripts.
3
votes
3answers
225 views
Fastest way to open all files in a directory with multiple file extensions on commandline
If I want to open all mp4 files in a directory, I can simply do something like totem *.mp4. But how can I open all mp4 and all flv files in that directory with one command. I.e. I want to do something ...
11
votes
2answers
216 views
Can I make `rm` interactive only when using globbing? (in either bash or zsh or both)
Whenever I rm multiple items at once with shell globbing and there's even the slightest possibility that the pattern expands to more than I expect it to, I always try to remember to add -i, but (of ...
1
vote
1answer
369 views
Do shells support recursion?
I'm trying to write recursive functions in my shell scripts.
Consider the following code:
function printA {
if [[ "$1" = 0 ]]; then
return
else
echo "a$(printA $(("$1" - 1)))"
...
1
vote
1answer
107 views
How to find/correct error in a path
It's often that a long path is mistyped or you get a log file entry that a path does not exist. Is there a command or shell function that navigates the path hierarchy until it finds a matching path?
...
7
votes
2answers
332 views
Shell Script for going through a dir recursively and chmodding based on conditions of file type
Can anyone point me to either code or a tutorial for writing a shell script that can recursively go through an entire directory structure (starting at the current working directory, or given an ...
6
votes
3answers
931 views
Switching to `zsh`: Are all bash scripts compatible with `zsh`?
I'm looking to switch from bash to zsh but concerned about compatibility of bash scripts.
Are all bash scripts/functions compatible with zsh? Therefore, if that is true is zsh just an enhancement to ...
2
votes
1answer
109 views
When is using ~+ useful?
As I understand it, ~+ means the same thing as "the current working directory".
So echo ~+ should print the same as pwd.
What is the purpose of this tilde expansion ~+ ?
2
votes
3answers
6k views
Change font in echo command
Is it possible to change the font attributes of the output of echo in either zsh or bash?
What I would like is something akin to:
echo -n "This is the font: normal "
echo -n $font=italic "italic,"
...
2
votes
2answers
209 views
Shell Prompt Customization?
I have used oh_my_zsh (and tinkered with bash_it) on multiple systems and have generally been happy with it, though I hate it's auto-correction feature and generally turn it off.
My usual shell is ...
3
votes
3answers
246 views
Converting a history to a script?
Often times I've typed in a bunch of commands when I realize that I am going to keep typing them in and that I would really like a script.
Now I understand that no matter how I save my history, I am ...
5
votes
1answer
80 views
What is Bash's string{ending1,ending2} construct called and what is the equivalent in zsh?
I've been trying to switch to zsh. Something I've missed so far is this:
#!/bin/bash
mv /very/long/path/to/file1.conf{,.old}
#bash expandes that to:
mv /very/long/path/to/file1.conf ...
7
votes
3answers
348 views
What is the main problem someone migrating from bash to zsh should face?
A few times I have had problems in bash that other using zsh didn't have and they were gloating about how smart they are.
Also I have seen zsh users among people that I admire, and I have tried a ...
4
votes
2answers
1k views
Screen status bar to display current directory for zsh/bash shell
I use GNU screen a lot with zsh as my shell. It would be a nice feature (I think) to be able to display the current directory name (not the full path) as the tab title. I can do that with CTRL+A ...
1
vote
1answer
738 views
Errors after installing oh-my-zsh
I just tried to install oh-my-zsh. I get the following error when I try to run rvm:
zsh: command not found: rvm
I also get the following error when I try to open a new tab:
...
6
votes
3answers
3k views
How do I reverse a for loop?
How do I properly do a for loop in reverse order?
for f in /var/logs/foo*.log; do
bar "$f"
done
I need a solution that doesn't break for funky characters in the file names.
5
votes
2answers
758 views
Pasting from clipboard to vi-enabled zsh or bash shell
I'd like to be able to paste from the system clipboard (or text selection) into my "vi-like" shell prompt using the keyboard. I normally use zsh and sometimes bash. In both cases, I have the shell set ...
4
votes
2answers
73 views
If ^a^b replaces “a” once in the last command, what do I use to replace all occurrences of “a”?
In bash, if I run this command:
echo aaaaaaa
I get aaaaaaa (duh)
But then if I type in
^a^b
I end up with baaaaaa
What would I type to end up with bbbbbbb ?
3
votes
3answers
372 views
What does : ${param:=value} mean?
I read the following in A User's Guide to the Z-Shell:
A synonym for ‘true’ is ‘:’; it’s often used in this form to give
arguments which have side effects but which shouldn’t be used —
...
6
votes
2answers
408 views
Difference between alias in zsh and alias in bash
I have searched around but could not find anything conclusive. Is there a difference between the alias command in zsh and the alias command in bash? If not, does it mean I can share a set of aliases ...
22
votes
1answer
623 views
Avoiding “BASH-isms” in shell scripts
Does there exist a tool similar to Perl::Critic that will inspect your shell scripts and point out flaws, portability issues, uses of non-standard programs without fallbacks, depreciated program uses, ...
13
votes
1answer
6k views
For loops in zsh and bash
I have noticed there are two alternative ways of building loops in zsh:
for x (1 2 3); do echo $x; done
for x in 1 2 3; do echo $x; done
They both print:
1
2
3
My question is, why the two ...
2
votes
2answers
1k views
Spaces as line breaks from inline for loop command
Someone care to enlighten me as to why the spaces in the first command seem to be interpreted as line breaks? Also occurs substituting print for echo.
$for l in $( find *.txt -exec head -1 {} \; ); ...
