How can I get a slice of $@ in Bash without first having to copy all positional parameters to another array like this? argv=( "$@" ) echo "${argv[@]:2}";

I want to list all the directories in present directory and pass those directories as a argument to another find command The below example will explain it correctly.

$ find . -maxdepth 1 -type d
.
./dir1
./dir2
./dir3
./dir4

$ echo -e "\n" ; find (above directories as argument) -exec md5sum {} +

So that I get checksum values for every files in a folder separately, separated by space. I think the above example explains the problem correctly Sorry for my bad English and I have very little knowledge on Linux command please forgive me Thank you in advance.

GNU has long pushed for a combination of short options (-h) and long options (--help), which goes a long way to clearing up the syntactical mess of commands like tar and dd, with their legacy syntax going back to the stone age. But I recently learned that GNU's parted has a _third_ kind of option, where an 'undocumented feature' can be accessed with ---pretend-input-tty. It looks like it was introduced in this commit in 2007. It's the first time I've seen that, and I'm intrigued. Is this some kind of wider convention, or just a one-off?

Both files are being used to pass parameters to the kernel. so what exacly is the difference between the two? What is the purpose of each file?

I want to run several jobs in parallel using the a script that does serial calls to a parameterized script and submits it as a background job on each call. It's for a brute force script which on each call will run 1k of 10k total combinations. The following is my first hack at it. #!/bin/bash for i in $(seq 10) do ./tmp/tmpsky/bd25Par.sh (i*1000-1000) (i*1000) & done I want $1 to evaluate as 0,1000,2000 etc...and $2 to evaluate to 1000,2000,3000 etc. The & is to submit the script as a background job. The called module will pass $1 and $2 to be used with seq as follows #/bin/bash/ for n in $(seq $1 1 $2) do ...` The first script fails with unexpected token 'i*1000-1000' What have I done wrong?

In the official documentation of [Samba](https://www.samba.org/) , the [smb.conf(5)](https://www.samba.org/samba/docs/current/man-html/smb.conf.5.html) page has an "Explanation Of Each Parameter" section. For some parameters, two possible values (either (G) or (S)) are shown at the end of the name, but nothing for others. What do (G) and (S) mean in samba's parameter configuration? (and _empty/nothing_?)

In particular I want to allow the following command without password:

sudo cfgutil --ecid "${Device_ECID}" install-application "${in_File_Name}"

With Device_ECID and in_File_Name changing from one call to the next. I found several examples but most about about the opposite: prohibition variable parameters entirely or allowing any parameters. ----- **Update:** Shortly after posting I found out about wildcards. The following works for me:

%_developer ALL=(root) NOPASSWD: /usr/local/bin/cfgutil list-devices
%_developer ALL=(root) NOPASSWD: /usr/local/bin/cfgutil --ecid * install-application *

However, from @marcus-müller answer I take it that this is only the case because there are no actual spaces in the filename. So I wonder is there is something else I'm still missing.

I'm using parameter substitution with an error message, such as

${var1:?'some message'}

. I've incorporated a multi-line error message. Presently, it only functions properly when enclosed within single quotes, with line breaks inserted using the Enter key. Is there a clever way to allow acceptance of multiple lines, saved separately? I'm just curious about exploring this. Please avoid suggesting alternative syntax involving if statements unless it's directly relevant. **Cases:** works: single quote

needed=${1:?'first error line
second error line
third error line'}

not working: call another string variable

usage_message='Please use this script by providing the following arguments:
1: 
2: 
3: '

username=${1:?$usage_message}
run_script_path=${2:?$usage_message}
where_to_save=${3:?$usage_message}

not working: call a function

function get_message {
       echo -e "first line \nsecond line\nthird line"
       # or
       # printf "first line \nsecond line\nthird line"
}

needed=${1:? $(get_message)}

Other discussion about parameter substitution: https://stackoverflow.com/a/77772942/13413319

I have two aliases watchExpand and l. I know that you can make bash expansion work with aliases by placing a trailing space like so: alias watchExpand='watch ' l is aliased to ls -larthiF --context. So when I type the command watchExpand l it works like a charm. However if I supply a parameter to watchExpand command, e.g. watchExpand -n 1 l My l alias no longer works. How can I get bash expansion after arguments?

I have read that positional parameters start at $1 (for example: $1, $2, $3 and so on are positional parameters). But $0 is not a positional parameter. But why $0 is not a positional parameter? I think this could be a reason, but not sure: Positional parameters only take their values when a script is executed. For example: if we do ./myScript Hello, then $1 will have the value Hello. But $0 can take its value on two occasions: when a script is executed (it would have the value of the script name), and when bash itself is executed without a script (it would have the value bash or -bash).

I'm looking to replace the group separator control character, which is printed by the terminal as "^]" and has got octal code of: 035, with a space. This can simply be done using tr, like so: echo $line | tr '\035' ' '. However, I don't (can't) use an external command in my bash script, so am instead looking to use parameter expansion to replace the control characters with spaces. What is the correct syntax to match the control character, the below options don't work:

${line//'\035'/' '}
${line//'\0035'/' '}
${line//\035/' '}
${line//$'\035'/' '}

Or is there another way to replace the character without using external commands such as tr and sed?

- I want to create 12 directories named after the months. So I tried using locale to get the month names, piping to tr to separate them with commas, then put braces around and passed to mkdir. But the whole is treated as one string. Is there a way to avoid this?

16:07: temp ⧲ mkdir {$(locale mon | tr \; ,)}

16:18: temp ⧲ ls -lh
total 4.0K
drwxr-xr-x. 2 john john 4.0K Dec 11 16:18 {January,February,March,April,May,June,July,August,September,October,November,December}

16:18: temp ⧲

One of my Flatpak application stopped working properly, probably after a silent upgrade. I found a fix online that tells me to add a parameter. That fix works. Nonetheless, I like running that app from the GUI as it's much less time consuming than typing its full name in the console. For a concrete example, my program is VSCodium, installed with Flatpak. The fix is to run it with GPU disabled. Currently, the GUI runs the command flatpak run com.vscodium.codium with probably a few more parameters, I would like it to run flatpak run com.vscodium.codium --disable-gpu, keeping those extra parameters. If it were an app installed through the native package manager, I'd modify the .desktop shortcut, but I can't find the ones created by flatpak, if any. How do I achieve that? (Where are the .desktop files or is there a better way?)

I've got four files:

./
./myscript.sh
./arguments.txt
./test.sh

Inside myscript.sh, I have to run the file test.sh, passing to it the arguments contained inside arguments.txt. myscript.sh is:

-bash
arguments=$(cat arguments.txt)
source test.sh $arguments

This works well *if arguments.txt contains at most one* argument:

firstargument

The substitution is:

-shellsession
++ source test.sh 'firstargument'

But the problem is with two or more arguments. It does this:

-shellsession
++ source test.sh 'firstargument secondargument'

Also, I don't know in advance the number of arguments inside arguments.txt. There can be zero or more.

For bash script, I can use "$@" to access arguments. What's the equivalent when I use an alias?

I am trying to make a flames game in shell script. I take 2 names and sort names. My code like this:

-bash
var=$(j=1;for((i=0;i]/{printf $2}') #checking for differernt characters using diff and folding using fold to newline after every 1 character (fold -w1)

Now the actual problem I am facing is in the flames part. I am running a loop to check for the length of the different sting and at that position or iteration whatever character is there to remove it from this:

-bash
flames()
{
    echo "$word ${#word}"
    size=echo ${#var2}
    
    for((i=0;i<${#word};i++))
    do
        echo  " ${word:$i:1}"

        if [[ $i == $size ]]
        then
            cha=echo ${word:$i:1}
            word1=echo ${word//$cha/}
        fi
    done
    
    word=echo $word1
    echo "$word ${#word}"
}

What its doing is its working till the value of size is equal to the i value . After that I am unable to understand how to check for and remove till there is just one character left?

-bash
while [ ${#word} -ne 1 ]
do
    flames
done

The above portion is running infinitely . Also is there any other way to doing it better than actually doing the parameter expansion?

I've defined a short helper function in a bash script. For legibility, I'd like to replace the boilerplate headers with a variable declared outside the function. I've tried quoting the declaration many different ways, but nothing's working. I want to replace this put() { local response=$(curl -H 'Content-Type: application/json' -H 'Accept: application/vnd.urbanairship+json; version=3;' ...) echo $response } with something like this headers=??? put() { local response=$(curl $headers ...) echo $response } i.e. $headers should expand to -H 'Content-Type: application/json' -H 'Accept: application/vnd.urbanairship+json; version=3;' $headers needs to expand to separate words to get passed properly as arguments, so I've even tried using an array. Note: I've pretty much given up. It's not worth fighting with for such a simple use. At this point the question is for edification.

Hello I have this in my ~/.bash_profile export GOPATH="$HOME/go_projects" export GOBIN="$GOPATH/bin" program(){ $GOBIN/program $1 } so I'm able to do program "-p hello_world -tSu". Is there any way to run the program and custom flags without using the quotation marks? if I do just program -p hello_world -tSu it'll only use the -p flag and everything after the space will be ignored.

I've found some special parameters in Bash that start with $ (the dollar sign). For example, when I wanted to know the exit status, I used $?. For getting the process ID, there's [$$](https://askubuntu.com/q/496054) . What are the special Bash (shell) parameters and their usage?

Given a directory containing: * note 1.txt, last modified yesterday * note 2.txt, last modified the day before yesterday * note 3.txt, last modified today What is the best way to fetch the array note 3 note 1 note 2? To define "best," I'm more concerned about robustness (in the context of Zsh in macOS) than I am about efficiency and portability. The intended use case is a directory of hundreds or thousands of plain text files, but—at the risk of muddling the question—this is a specific case of a more general question I have, of what best practices are in performing string manipulations on filepaths printed by commands like ls, find, and mdfind. --- I've been using a macro which invokes this command to achieve the above:

ls -t | sed -e 's/.[^.]*$//'

It's never failed, but: * [Greg's Wiki](http://mywiki.wooledge.org/EnglishFrontPage) strongly recommends against parsing the output of ls. ([Parsing ls](http://mywiki.wooledge.org/ParsingLs) ; [Practices](http://mywiki.wooledge.org/BashGuide/Practices) , under "5. Don't Ever Do These"). * Is invoking sed inefficient where parameter expansion would do? Using find (safely delimiting filepaths with NUL characters rather than newlines), and parameter expansion to extract the basenames, this produces an unsorted list:

find . -type f -print0 | while IFS= read -d '' -r l ; do print "${${l%.*}##*/}" ; done

But sorting by modification date would seem to require invoking stat and sort, because macOS's find lacks the -printf flag which [might otherwise serve well](https://superuser.com/a/546900) . Finally, using Zsh's [glob qualifiers](http://zsh.sourceforge.net/Doc/Release/Expansion.html#Glob-Qualifiers) :

for f in *(om) ; do print "${f%.*}" ; done

Though not portable, this last method seems most robust and efficient to me. Is this correct, and is there any reason I shouldn't use a modified version of the find command above when I'm actually performing a search rather than simply listing files in a directory?