Questions tagged [arguments]

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

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1answer
544 views

How can I use a loop inside a command?

I'm writing a shell script that contains a command that takes multiple directories as space-separated input arguments (like ls). I would like to fill in those arguments from a variable but don't know ...
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1answer
5k views

How to pass arguments to 'source' command?

My source command in the CShell goes like this : source /directory/of/script/script.csh The script.csh executes and in between, waits for my password to confirm the identity. I am tired of typing ...
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1answer
831 views

Bash: show prompts if arguments weren't provided

What is the best way of supporting in the script prompts and arguments at the same time? I want to show prompts if arguments weren't provided. Is there something better/shorter than this? ⇩ ...
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2answers
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CP: max source files number arguments for copy utility

Consider that there are countless number of files under /src/ cp /src/* /dst/ How many files cp will successfully process?
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2answers
458 views

Command substitution interpreting spaces within quotes as argument separators

I'd like an alias that additionally appends itself to ~/.bashrc, e.g. function tailias { $(echo "alias $1='${*:2}'" | tee -a ~/.bashrc) } I'm using tee to split the command to ~/.bashrc while ...
138
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7answers
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Pass the output of previous command to next as an argument

I've a command that outputs data to stdout (command1 -p=aaa -v=bbb -i=4). The output line can have the following value: rate (10%) - name: value - 10Kbps I want to grep that output in order to store ...
2
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0answers
769 views

Mounting root filesystem while booting through network

I have two systems, let say one is the server and the other is the client. I want to load kernel image from the server to the client through the network. I used dhcp (isc-dhcp-server) and tftp (...
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1answer
1k views

Using sed output in another script or command

How can I use the output of sed in another script? For example (this doesn't work): sed -n "$COUNTER",1p /domains.csv | wget or sed -n "$COUNTER",1p /domains.csv > /myScript.sh As far as I ...
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1answer
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How to get variables from the command line while makefile is runing?

Such as in bash script: read -p "Only UI(y/n)" Temp_Answer. Is it possible to do this while Makefile is runing? Because I want to do different base on the $Temp_Answer (Y or N) in Makefile.
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1answer
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How to use command line arguments in a shell script [duplicate]

I have a shell script and when invoking it ./test it asks for an input.I 've seen a quicker way just by writing at once ./test myInput ,how is that achievable?
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3answers
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Correctly parse arguments in script behaving like a shell called through SSH

I have a server with a very limited used whom I want to be able to run two very specific (and custom) instructions through SSH. In order to do that, I have set the shell for that limited user to be a ...
8
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2answers
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Bash globbing and argument passing

I have the following simplified bash script #!/bin/bash files=("$@") if [ "X$files" = "X" ]; then files=$HOME/print/*.pdf; fi for file in "${files[@]}"; do ls "$file"; done If I pass ...
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9answers
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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 ...
17
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2answers
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How can I stream data to a program that expects to read data from a file that is given as a argument?

I have a huge gzipped file and I want a program (4s-import in this case) to read it. It takes a lot of time to first unzip the file and then call the program with the path to the file as an argument. ...
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2answers
286 views

Meaning of the following linux commands

cat "$1" > /tmp/file.$$ 2>/tmp/file0.$$ grep "*" /tmp/file.$$ >/tmp/file0.$$ I understood that in the cat command, if an error occurs, the error will be shown in file0.$$ and if it ...
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2answers
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Making md5sum understand file names with spaces

I need to use md5sum in Python by using pipe to calculate checksum for a bunch of .mp3 files... is there a command which ignore whitespaces in filenames on the command line of md5sum program? For ...
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3answers
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What is a “non-option argument”?

I am trying to understand info who but completly fail at the term »non-option argument«. Can someone please explain this term to me in simple words or an example? UPDATE: from ' info who' ...
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5answers
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How to use filename arguments or default to stdin, stdout (brief)

I want to handle filenames as arguments in a bash script in a cleaner, more flexible way, taking 0, 1, or 2 arguments for input and output filenames. when args = 0, read from stdin, write to stdout ...
1
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1answer
417 views

devilspie detect if application was started with a flag

How can I set devilspie to detect if an application was started with the flag --hello-world from terminal? For example window_name detects the window title. How can transform in devilspie the ...
3
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3answers
2k views

Convert newline-delimited list with spaces into arguments [duplicate]

I'm trying to write a script that I can run from the context menu in Caja (a clone of Nautilus). Its purpose is to pass the files that are selected in the file manager to a given program (for example, ...
1
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1answer
2k views

--no-desktop and %U what for?

I want to know why is this argument so important when lauching nautilus or pcmanfm. What happens if i don't? Also, i want to know what is the meaning of %U for: Exec=pcmanfm %U
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2answers
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How does ps know to hide passwords?

Witness: $ ps f PID TTY STAT TIME COMMAND 31509 pts/3 Ss 0:01 -bash 27266 pts/3 S+ 0:00 \_ mysql -uroot -p 25210 pts/10 Ss+ 0:00 /bin/bash 24444 pts/4 Ss 0:00 -...
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4answers
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How can I print “-n” with `echo`?

I can't figure how to print the string "-n" with the over 30 years-old command echo. I tried these: Michaels:Scripts$ echo -n Michaels:Scripts$ echo "-n" Michaels:Scripts$ echo -e "-n" Michaels:...
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2answers
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Why do I need the double dash before argument passed to sh by xargs -I for it to work properly?

Here is the command in question find . -name "*.txt" | xargs -Ifile sh -c 'echo $(basename $1) ' -- file So without the double dash the file is not passed to sh and then get recognized as $1. Why ...
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5answers
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cp with a single argument containing wildcards [duplicate]

If I have the following 2 files and 1 folder: someuser@computer:~/Desktop/test$ ls -l total 340 -rw-r--r-- 1 someuser someuser 45082 ago 5 09:56 file1.pdf -rw-r--r-- 1 someuser someuser 291836 ago ...
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3answers
12k views

Is there an easy way to log all commands executed, including command line arguments?

I am trying to find how to log a specific instantiation of rrdtool to see whether the path it is receiving is incorrect. I know I could wrap the executable in a shell script that would log the ...
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2answers
174 views

Is it possible to create a “file” that can be used by any process without actually saving the file on disk?

Suppose I do a grep that gives me a lot of results. I want to use the output of grep and pass it to a command that takes a filename as it's first argument. For example - myCommand filename.txt I ...
22
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4answers
29k views

find + xargs: argument line too long

I have a line like the following: find /foo/bar -name '*.mp4' -print0 | xargs -i {} -0 mv -t /some/path {} but I got the following error: xargs: argument line too long I am confused. Isn't the use ...
13
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3answers
13k 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. ...
16
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2answers
33k views

how to loop through arguments in a bash script

I would like to write a bash script with unknown amount of arguments. How can I walk through these arguments and do something with them? A wrong attempt would look like this: #!/bin/bash for i in $...
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2answers
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UNIX-, BSD-, GNU-options in Linux's ps command. Where are they from?

In the manual for the ps command on Ubuntu there is this text: This version of ps accepts several kinds of options: 1 UNIX options, which may be grouped and must be preceded by a dash. ...
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2answers
16k views

Pass arguments to function exactly as-is

I have the following function: bar() { echo $1:$2; } I am calling this function from another function, foo. foo itself is called as follows: foo "This is" a test I want to get the following output:...
4
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2answers
4k views

shell script options pass through to sub-command

I'm writing a wrapper script for that uses getopts to set various options for mysqldump. It's working well so far. However one thing I would like to do is be able to add another option in my shell ...
25
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4answers
30k views

Is there a way to refer to multiple files in a directory without retyping the whole path? [duplicate]

In a bash shell, when I have to remove multiple files in the same directory, I currently need to do something like this: rm /some/path/file1 /some/path/file2 Is there a shorter way to write this so ...
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1answer
3k views

Delimiters of program arguments?

What is the syntax to delimit the arguments of a C program. For example, if I type : ./myprogram 1 2 3 | grep result The | grep result will be interpreted as arguments (and passed as argv). So how ...
9
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4answers
9k views

Passing multiple directories to the -prune option in find

I am using find to locate and delete backup files but wish to exclude certain directories from the search. The backup filenames could terminate in .bck, bak, ~, or backup. The Minimal Working Example ...
7
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3answers
1k views

Bash : command line with optional arguments

I'm running this kind of code: #!/usr/bin/env bash set -u exclude1='--exclude=/path/*' exclude2='--exclude=/path with spaces/*' exclude3='' # any 'exclude' can be empty tar -czf backup.tgz "$...
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2answers
206 views

Key letters? Option letters? What are these things?

Some GNU and GNU-like tools seem to accept options in a combined manner, e.g. foo -hgcf instead of foo -h -g -c -f. An example is tar, as in tar cXbf keepout 20 archive.shar *.txt instead of tar -c -...
1
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1answer
120 views

Why is $* not working as expected?

I'm trying to use $* in a function to expand to all commandline arguments in a function, but it's giving me bizarre behavior: $ function repeat() { echo "$*" } $ repeat puts hello # this gives me ...
3
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1answer
144 views

How to put an argument vector with an argument containing spaces in a bash variable

How can I store an argument vector with an argument containing spaces in a bash variable? For example, I want 2.sh to print b c 1.sh #!/bin/bash ARGV='a "b c"' ./2.sh $ARGV 2.sh #!/bin/bash ...
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2answers
5k views

Pattern matching from the input arguments

We're trying to enhance one of our scripts. Users will pass some arguments and part of the arguments will have 5.0.3. For an example, the input argument would be like Jboss5.0.3GA. Since it ( Jboss5....
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5answers
7k 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. ...
5
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2answers
9k views

How do I pass the contents of a file as a command line parameter

I am storing a file path in a file and need to pass the contents of that file as an argument to a shell script, specifically Maven, something like so: mvn -Dvar_name=(contents of file) Would this ...
4
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2answers
2k views

Bash: passing braces as arguments to bash function

I love using the following pattern for searching in files: grep --color=auto -iRnHr --include={*.js,*.html,} --exclude-dir={release,dev,} "span" . I'd like, however, to have this one wrapped into a ...
5
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3answers
3k views

How to pass arguments to bash shell script when executing that command with at?

I have a shell script that accepts an argument and uses that in the script. So to run the script I type /path/to/script argument The problem is when trying to setup that file to run using the at ...
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1answer
302 views

Why do many CLI apps take a single “--” argument? [duplicate]

Possible Duplicate: What does “--” (double-dash) mean? There are many command line tools that take a single "--" argument. For example: gem install mysql -- —–with-mysql-config=/usr/local/mysql/...
1
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1answer
114 views

Redirection doesn't show up as an argument to a sourced script

My problem is that I can't print to the screen when I write a bash script . myBashScript.sh < text.txt In myBashScript.sh I just print out echo $2 But instead of printing "text.txt", it show ...
17
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2answers
18k 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 file_name ...
9
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2answers
2k views

What is a canonical way to find the actual maximum argument list length?

Following ARG_MAX, maximum length of arguments for a new process it seems like ARG_MAX is wrongly (or at least ambiguously) defined on my Mac Mini 3,1 running Ubuntu 12.04: $ getconf ARG_MAX # ...
90
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8answers
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What is the difference between $* and $@?

Consider the following code: foo () { echo $* } bar () { echo $@ } foo 1 2 3 4 bar 1 2 3 4 It outputs: 1 2 3 4 1 2 3 4 I am using Ksh88, but I am interested in other common ...

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