remove a file called -l from command line (Centos) - unix

Someone accidentally created a file name '-l' and I cannot remove it, because rm -l interprets the filename as a flag. I've tried quotes, escaping and nothing is working.

In virtually all Unix commandline utilities you can use a double-dash -- to separate options from arguments. Under the hood, getopt will stop attempting to parse arguments as options when it first encounters a --. From the docs:
getopt has three ways to deal with options that follow non-options argv elements. The special argument ‘--’ forces in all cases the end of option scanning.
In your specific case with rm, use:
$ rm -- -l

Related

Zsh completions with multiple repeated options

I am attempting to bend zsh, my shell of choice, to my will, and am completely at a loss on the syntax and operation of completions.
My use case is this: I wish to have completions for 'ansible-playbook' under the '-e' option support three variations:
Normal file completion: ansible-playbook -e vars/file_name.yml
Prepended file completion: ansible-playbook -e #vars/file_name.yml
Arbitrary strings: ansible-playbook -e key=value
I started out with https://github.com/zsh-users/zsh-completions/blob/master/src/_ansible-playbook which worked decently, but required modifications to support the prefixed file pathing. To achieve this I altered the following lines (the -e line):
...
"(-D --diff)"{-D,--diff}"[when changing (small files and templates, show the diff in those. Works great with --check)]"\
"(-e --extra-vars)"{-e,--extra-vars}"[EXTRA_VARS set additional variables as key=value or YAML/JSON]:extra vars:(EXTRA_VARS)"\
'--flush-cache[clear the fact cache]'\
to this:
...
"(-D --diff)"{-D,--diff}"[when changing (small files and templates, show the diff in those. Works great with --check)]"\
"(-e --extra-vars)"{-e,--extra-vars}"[EXTRA_VARS set additional variables as key=value or YAML/JSON]:extra vars:__at_files"\
'--flush-cache[clear the fact cache]'\
and added the '__at_files' function:
__at_files () {
compset -P #; _files
}
This may be very noobish, but for someone that has never encountered this before, I was pleased that this solved my problem, or so I thought.
This fails me if I have multiple '-e' parameters, which is totally a supported model (similar to how docker allows multiple -v or -p arguments). What this means is that the first '-e' parameter will have my prefixed completion work, but any '-e' parameters after that point become 'dumb' and only allow for normal '_files' completion from what I can tell. So the following will not complete properly:
ansible-playbook -e key=value -e #vars/file
but this would complete for the file itself:
ansible-playbook -e key=value -e vars/file
Did I mess up? I see the same type of behavior for this particular completion plugin's '-M' option (it also becomes 'dumb' and does basic file completion). I may have simply not searched for the correct terminology or combination of terms, or perhaps in the rather complicated documentation missed what covers this, but again, with only a few days experience digging into this, I'm lost.
If multiple -e options are valid, the _arguments specification should start with * so instead of:
"(-e --extra-vars)"{-e,--extra-vars}"[EXTR ....
use:
\*{-e,--extra-vars}"[EXTR ...
The (-e --extra-vars) part indicates a list of options that can not follow the one being specified. So that isn't needed anymore because it is presumably valid to do, e.g.:
ansible-playbook -e key-value --extra-vars #vars/file

Globbing not working as expected

I would like to list all plain files that are not python scripts in zsh.
Why does the following "code" not work and what is the proper solution?
ls -l *(.)~*.py
UPDATE:
I have setopt extended_glob in my .zshrc.
And
ls -ld *~*.py``
works as expected.
(I added the -d in the command to prevent directories from getting expanded).
The problem is that ~ is a glob operator (that also requires EXTENDED_GLOB be set), while (.) is a glob qualifier, which means it must be added to the end of the entire pattern, not used in the middle. Use
ls *~*.py(.)
instead. That is, *~*.py is your pattern (all files not ending in .py), and (.) is applied to the results. (Perhaps yet another way to put it is to say that glob operators can only work on unqualified patterns.)

How can I implement the command 'ls' with wildcard, '*'?

EDIT #1 : I'm under the limit that all arguments are enclosed in two quotes, so that shell do not expand any argument with * to the corresponding path.
EDIT #2 : In order to retrieve directories such as */*, ../*, and dirA/*/file.out, How should I use iteration loop or recursive call?
I have just learned about the function fnmatch(). But I don't know start place.
There are many possible cases. I'm confused dealing with these all cases.
For example, Let me assume that executable program is a.out.
$./a.out -l */*
$./a.out -l ../*
$./a.out -l [file_name] [directory_name]
/* Since I also have to implement ls command with no wildcard. */
What should I do? Any advice would be awesome.
Thank you in advance.
Your problem is : shell replaces wildcard caracter * with all of the filenames matching the pattern.
Solution:
If you do not want to use this feature of bash, just put quotation marks around your command line arguments.
Calling your program that way will have the original arguments, containing wildcards.
After this, you can list all the filenames with their paths. For example using some recursive algorithm. Then you can apply some matching to these path string. (when visiting it)
If you want to be a good unix citizen, the rule is Don't do filename globbing unless you are writing a shell.
You want to write an ls-like program? Don't do any wildcard expansion. Don't treat "*" specially. Just treat your argv as a list of filenames. If your program handles these cases:
./a.out file1
./a.out file1 file2 file3
Then it will also handle
./a.out file*
correctly because the shell will do the expansion and your program won't need to know about it. And besides that, it will handle this:
zsh% ./a.out **/file<40-185>~file<90-100>(.mm-30OL[1,2])
which in zsh expanded glob syntax means: expand file40 through file185, except for file90 through file100, include only the ones that have been modified in the last 30 minutes, and use only the largest 2 files in the resulting set.
fnmatch is never going to do anything like that. But these fancy globs can be used with any command that just takes a filename list and doesn't care where it came from.
When you're in a situation where you can't take a list of filenames from the command line, then consider using fnmatch. ls isn't one of those situations.

case insensitive glob listing in zsh

I have the following code:
$ print -l backgrounds/**/*.((#i)jpg|jpeg|gif|webp|png|svg|xcf|cur|ppm|pcd)
the intention was to list some image file indifernet of the case of file termination.
But my code seems to not be functional because won't list files whit uppercase endings.
Can someone explain my error in the above code example?
Thanks in advance.
You need the #i to apply to everything, not just jpg. You can use:
$ print -l backgrounds/**/*.(#i)(jpg|jpeg|gif|webp|png|svg|xcf|cur|ppm|pcd)
Make sure you have also done:
set -o extended_glob
Note that using #i requires that EXTENDED_GLOB be set in your script/shell:
setopt EXTENDED_GLOB
See the docs, section 1.8.4 Globbing Flags, or type man zshexpn.
And you want: *.(#i)(jpg|gif|etc)

how does unix handle full path name with space and arguments?

How does unix handle full path name with space and arguments ?
In windows we quote the path and add the command-line arguments after, how is it in unix?
"c:\foo folder with space\foo.exe" -help
update:
I meant how do I recognize a path from the command line arguments.
You can either quote it like your Windows example above, or escape the spaces with backslashes:
"/foo folder with space/foo" --help
/foo\ folder\ with\ space/foo --help
You can quote if you like, or you can escape the spaces with a preceding \, but most UNIX paths (Mac OS X aside) don't have spaces in them.
/Applications/Image\ Capture.app/Contents/MacOS/Image\ Capture
"/Applications/Image Capture.app/Contents/MacOS/Image Capture"
/Applications/"Image Capture.app"/Contents/MacOS/"Image Capture"
All refer to the same executable under Mac OS X.
I'm not sure what you mean about recognizing a path - if any of the above paths are passed as a parameter to a program the shell will put the entire string in one variable - you don't have to parse multiple arguments to get the entire path.
Since spaces are used to separate command line arguments, they have to be escaped from the shell. This can be done with either a backslash () or quotes:
"/path/with/spaces in it/to/a/file"
somecommand -spaced\ option
somecommand "-spaced option"
somecommand '-spaced option'
This is assuming you're running from a shell. If you're writing code, you can usually pass the arguments directly, avoiding the problem:
Example in perl. Instead of doing:
print("code sample");system("somecommand -spaced option");
you can do
print("code sample");system("somecommand", "-spaced option");
Since when you pass the system() call a list, it doesn't break arguments on spaces like it does with a single argument call.
Also be careful with double-quotes -- on the Unix shell this expands variables. Some are obvious (like $foo and \t) but some are not (like !foo).
For safety, use single-quotes!
You can quote the entire path as in windows or you can escape the spaces like in:
/foo\ folder\ with\ space/foo.sh -help
Both ways will work!
I would also like to point out that in case you are using command line arguments as part of a shell script (.sh file), then within the script, you would need to enclose the argument in quotes. So if your command looks like
>scriptName.sh arg1 arg2
And arg1 is your path that has spaces, then within the shell script, you would need to refer to it as "$arg1" instead of $arg1
Here are the details
If the normal ways don't work, trying substituting spaces with %20.
This worked for me when dealing with SSH and other domain-style commands like auto_smb.

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