An argument is usually defined as the actual value passed to a function, procedure, or command line program.

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5
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3answers
25k views

How do I echo just 1 column of output from ls command?

Lets say when I do ls command the output is: file1 file2 file3 file4 Is it possible to display only a certain column of output, in this case file2? I have tried the following with no success: echo ...
23
votes
2answers
2k views

When do I need to specify add_efi_memmap as kernel argument in UEFI/EFI boot?

I am reading some tutorials how to EFI stub (efistub) load the Linux kernel. These instructions often use kernel boot parameter add_efi_memmap. The intended hardware is Intel x64 having 8GB of RAM. My ...
5
votes
5answers
370 views

BASH: how to pass a default argument if no arguments after the first were passed

I have a bash script with a case statement in it: case "$1" in bash) docker exec -it $(docker-compose ps -q web) /bin/bash ;; shell) docker exec -it $(docker-compose ...
2
votes
2answers
6k views

What's the difference between STDIN and arguments passed to command?

I could use the either form to execute the cat method: cat file_name cat < file_name The result is the same Then I want to execute man in the format of stdin man < file_name While ...
4
votes
1answer
56 views

How to remove a positional parameter from $@

Basically, I want to "pluck out" the first occurrence of -inf from the parameter list. (The remaining parameters will be passed along to a different command.) The script I have has the following ...
1
vote
1answer
54 views

get first CLI argument after the options in shell scipt

I have a script I class like so gitploy up -t 2.0.0 test_repo. I pull out the "action" up right away, then I need to be able to get the test_repo before I process the options. I don't want to lose ...
1
vote
0answers
51 views

How do C programs pass whitespace arguments to the libc system(3) calls? [migrated]

When a C program calls system() to run a Unix command, I know it's possible to pass arguments to the command, and according to a StackOverflow answer (from a very high-rep user), the system() call ...
0
votes
1answer
19 views

get command line agrument by variable in shell script

I want to get the arg of a command from a var that has the index in it of the arg that I want. Something like this # command in terminal, `foo -r -f value_wanted` index="3" var=$"$index" echo $var ...
1
vote
1answer
42 views

How to prevent bash from transforming arguments?

I am trying to use an argument of the script to find other files. The problem is that when i give the script the argument x.* in the command line, it is transformed into x.sh. Any ideas how i can get ...
10
votes
4answers
822 views

Why doesn't echo called as /bin/sh -c echo foo output anything?

For example, while this works: $ echo foo foo This doesn't: $ /bin/sh -c echo foo Whereas this does: $ /bin/sh -c 'echo foo; echo bar' foo bar Is there an explanation?
0
votes
0answers
21 views

Match all arguments (like $@) except last? [duplicate]

I was only able to find solutions for matching all but $1. Like shift for example. Like: command argument1 argument2 argument3 argument4 I would match argument1, argument2 and argument3 but not ...
0
votes
4answers
10k views

How to write a Java Program / Shell Script combination such that you can call the Java program as a remote command and yet supply a local file?

This is related to How to execute a remote command on a local file? I wrote a simple Java program that prints the first line of a file - import java.io.BufferedReader; import ...
3
votes
2answers
91 views

Passing paths with spaces as arguments

I am having difficulty in passing some string variables having spaces in them as arguments to a program. For debugging and showing the arguments being passed, I created a demo Python script -: ...
6
votes
5answers
4k views

Bash script that reads filenames from a pipe or from command line args?

I want my script to read a bunch of filenames (which may have spaces) given either as a glob or from STDIN and do stuff with them. I've been able to read either way separately, but not combine them. ...
1
vote
1answer
36 views

globbing and $# [closed]

Suppose my shell script gets 3 arguments: ./myscript dir1 material dir2 I need $# to report the count of items globbed with dir1/* and not the count of my script's original 3 arguments. Do you ...
24
votes
5answers
24k views

Solving “mv: Argument list too long”?

I have a folder with more than a million files that needs sorting, but I cant really do anything because mv outputs this message all the time -bash: /bin/mv: Argument list too long I'm using this ...
2
votes
2answers
75 views

How to specify multiple input arguments stored in a file to a command?

I would like to convert several webpages into a pdf file, by: wkhtmltopdf http://think-like-a-git.net/sections/about-this-site.html ...
3
votes
2answers
70 views

Content of /proc/<PID>/cmdline file depends on script shebang?

I have a bash script named test.sh which I start with startproc. In case I use #!/usr/bin/env bash shebang in test.sh, the /proc/<PID>/cmdline file looks following: SERVER:~ # cat ...
0
votes
2answers
77 views

In a folder with many files how to do rm on lots of them [duplicate]

I just experimented a bit in linux and ended up getting very many files in one and the same folder. Now when I try to do rm -f folder/*.png I get -bash: /bin/rm: Argument list too long ...
0
votes
0answers
17 views

Difference between “$@” and “$*” when passing arguments to bash function [duplicate]

I'm having hard time understanding difference between $@ and $* when passing them to functions. Here is example: function a { echo "-$1-" "-$2-" "-$3-"; } function b { a "$@" } function c ...
1
vote
2answers
88 views

How does 'find -exec' pass file names with spaces?

If I have a directory containing some files whose names have spaces, e.g. $ ls -1 dir1 file 1 file 2 file 3 I can successfully copy all of them to another directory like this: $ find dir1 ...
0
votes
1answer
36 views

picocom -b 115200 - Why do you need to specify the baudrate?

I have an intel galileo board and if I try to connect to it from my laptop with: picocom /dev/ttyUSB0 I get just akward characters like: Terminal ready � ...
3
votes
1answer
114 views

How to determine program success when running a sequence of similar tasks?

I am writing a series of CLI tools that share the same parent command, similar to programs like git. program verb OPTIONS One of the action verbs, install, is designed to git clone as many ...
0
votes
2answers
84 views

While loop for bash scripting to read either stdin or arguments

I'm playing around with the accepted answer from this thread: Bash script that reads filenames from a pipe or from command line args? When I use the below script, efetch ...
2
votes
5answers
40 views

What determines how program arguments needs to be separated?

I noticed that kill utility is able to accept arguments separated both by a space character and a newline: $ sleep 120 & sleep 240 & [1] 75341 [2] 75342 $ /bin/kill $(echo "75341 75342") [1]- ...
1
vote
1answer
24 views

Alias gedit to accept an argument

This alias works in UNIX and in Redhat. It does not work in Fedora alias te 'gedit "\!*" &' Usage: te myfile.cpp It opens gedit with myfile.cpp in the edit window and runs in the ...
1
vote
2answers
36 views

pipe as arguments

I'm trying to use the output of a command as arguments: The command: /home/alexandre/dropbox.py exclude add ls | grep -v photos I have to add a list of files, for example: ...
1
vote
2answers
131 views

Call one shell script with another

If I have a program that multiplies the user-supplied value with 10, how do I write another bash script that has arguments passed to it and takes these arguments and collects the output of the other ...
1
vote
2answers
8k views

How to pass argument with spaces to a shell script function? [duplicate]

I'm trying to pass multiple argument to a function, but one of them is consist of two words and I want shell function to deal with it as one arg: args=("$@") function(){ echo ${args[0]} echo ...
5
votes
3answers
3k views

How to prevent command injection through command options?

I have an wrapper application where I need to let the user specify custom options to pass to a simulator. However, I want to make sure the user doesn't inject other commands through the user options. ...
1
vote
2answers
34 views

What does the `set — $args` line do here, and why does it behave differently between Zsh and Bash?

In the manpage for the version of getopt that comes with Mac OSX, an example is given that uses the construction args=$(getopt optstring $*); set -- $args. What does set -- $args do here? ...
0
votes
2answers
57 views

Passing contents of a file on the command line [duplicate]

I'm trying to figure out how I can send arguments (which are contents in a file) on the command line as parameters to a cpp function. I am NOT trying to send it through stdin. I have a function named ...
1
vote
1answer
50 views

Indirectly expand variables in shell

I need to indirectly reference a variable in the bash shell. I basically want to what you can do in make by writing $($(var)). I have tried using ${$var} which would be the most straight forward ...
3
votes
1answer
40 views

functions arguments

I am having trouble with what should be a simple bash script. I have a bash script that works perfectly: function convert_to () x_max=2038 y_max=1146 x_marg=100 y_marg=30 x_grid=150 y_grid=150 if ...
0
votes
1answer
49 views

Expand parameter in quotes in zsh

(Not sure the title is adequate, at least I tried my best…) I want to pass function arguments to zsh’s emulate to evaluate a command in bash emulation: $ .bash() { emulate bash -c "$*" } $ .bash ...
3
votes
2answers
165 views

What's the `name` argument to `sh` for/do?

Taken from FreeBSD's man page on sh (because its the most convenient online, target platform is Debian if it matters): SH(1) FreeBSD General Commands Manual SH(1) NAME sh -- ...
41
votes
7answers
3k views

Is `-` used only with cd?

cd - can switch between current dir and previous dir. It seems that I have seen - used as arguments to other commands before, though I don't remember if - means the same as with cd. I found that - ...
-1
votes
1answer
69 views

script with no arguments should echo a message, but it doesn't [closed]

I'm questioning why my script still does not run the condition when no argument is provided. I think it might be the ordering of my if statements but I'm not sure. Any advice? It doesn't seem to be a ...
15
votes
4answers
1k views

How can the standard input of one program be passed as an arg to another?

Let's say a program exists, which takes two arguments; input file and output file. What if I don't wish to save this output file to disk, but rather pass it straight to stdin of another program. Is ...
1
vote
2answers
49 views

Jump to specific flag in help/man file

Let's say I'm curious about what a specific flag -T means for a command ls? Is there a way to jump straight to that using man ls...? or, and this is a slightly different question because it's not ...
1
vote
2answers
43 views

Else not Executing

In my script, I transform data to a more readable format. But I am having an issue. If no arguments are typed, just the script, I want it to come back "Please enter a filename" which I have done. But ...
1
vote
0answers
45 views

Can't get bare-bone simple bash function to work [closed]

I have some tmux scripts in a directory, and I'm trying to make a script to make it easier to call them. Function is below tms() { ~/linux/scripts/tmux-scripts/$1 } This is in my bashrc, I then ...
1
vote
1answer
87 views

sh - Using Arguments in .profile functions

I want to use an argument in the function I created in my .profile file. I want to ask for input if no argument is given, otherwise set a variable to $1. When I check $1 to see if it is empty, I ...
0
votes
1answer
190 views

Bash if statement not working properly [closed]

I have a bash statement to test a command line argument. If the argument passed to the script is "clean", then the script removes all .o files. Otherwise, it builds a program. However, not matter what ...
3
votes
4answers
189 views

Provide strings stored in a file as a list of arguments to a command?

I install a list of URLs in a text file named myurls: http://www.examples.com/1 http://www.examples.com/2 http://www.examples.com/3 How shall I pass these URLs to wkhtmltopdf as inputs? The direct ...
0
votes
1answer
286 views

How many files can rm delete at once? [duplicate]

One of my friends wanted to have more logs in the /var/log/ directory, and after some time of using the system, he tried to access the folder and list it, but instead he got the following error: ...
3
votes
4answers
123 views

How do I get the value of a named option of an already running process in Linux?

I run the following command. ps -e -o args | grep destiny | grep UNIX I receive the following output. /path/to/destiny -r -m UNIX -t TCP -p 1501 What command can I use the get the value of the ...
26
votes
5answers
35k views

Passing named arguments to shell scripts

Is there any easy way to pass (receive) named parameters to a shell script? For example, my_script -p_out '/some/path' -arg_1 '5' And inside my_script.sh receive them as: # I believe this ...
0
votes
1answer
34 views

How does “command < filename.txt” look when passing filename into a command

I've got a scenario where I have command < filename.txt so I can pass the contents of filename.txt and use it in command. But say I want to take the contents out of the file and just use them in ...
13
votes
3answers
3k views

Why do some commands not read from their standard input?

I wonder what when we should use pipeline and when we shouldn't. Say for instance, to kill certain process which handling pdf files, the following will not work by using pipeline: ps aux | grep pdf ...