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2
votes
1answer
2k views

Is it possible to use a parameter within an alias command [duplicate]

Possible Duplicate: How to pass parameters to an alias? As answered in Can less retain colored output? I want to use git diff --color=always filename | less -r to get a colored output of my ...
4
votes
2answers
580 views

Passing parsed output of sed to find (in this direction)

Well, I think you can find dozens of questions on this platform how to pipe find output to sed, but I haven't found anything for the reverse direction so far. What I want to do is modify my input, and ...
4
votes
3answers
1k views

How to tell of whether the kernel parameter [passed at command line] is a valid kernel parameter?

In the grub.conf configuration file I can specify command line parameters that the kernel will use, i.e.: kernel /boot/kernel-3-2-1-gentoo root=/dev/sda1 vga=791 plasticDuck After booting up a ...
16
votes
1answer
18k views

How to display kernel command line parameters?

In the grub.conf configuration file I can specify command line parameters that the kernel will use, i.e.: kernel /boot/kernel-3-2-1-gentoo root=/dev/sda1 vga=791 After booting a given kernel, is ...
1
vote
2answers
393 views

Transforming positional arguments of a shell script

I'm trying to write a shell script that will transform positional arguments that are passed to it as follows. The shell script passes these arguments to a binary executable (ffigen) which is derived ...
3
votes
2answers
340 views

how to make getopts just read the first character post `-`

I have a shell script testShell.sh which uses getopts as below: #!/bin/bash while getopts ":j:e:" option; do case "$option" in j) MYHOSTNAME=$OPTARG ;; e) SCRIPT_PATH=$OPTARG ;; ...
2
votes
5answers
1k views

Where are command line arguments (e.g. 'some.text') actually passed to?

From what I know, parameters you pass to a command, goes to it's STDIN stream. so this: cut -d. -f2 'some.text' should be perfectly identical to this: echo 'some.text' | cut -d. -f2 as we send ...
2
votes
2answers
928 views

what does Curl's stand-alone hyphen (-) mean?

what's the stand-alone hyphen (between the -C & -O) stand for in this command? curl -C - -O http://www.intersil.com/content/dam/Intersil/documents/fn67/fn6742.pdf FWIW- I'm following a ...
1
vote
1answer
1k views

Passing Command Line Arguments to java From JPackage Script

I installed Rachota -- a time tracking program written in Java -- from the Fedora repo, and yum installed the rachota.jar file to /usr/share/java, but it also created a script at /usr/bin/rachota. ...
3
votes
1answer
200 views

How can I pipe a path to pushd?

This seems like it should be easy enough to do, but I'm clearly not understanding something fundamental about piping output back and forth. I'm trying to do something like this: bundle show ...
4
votes
1answer
465 views

Writing command synopsis in standard man format

I am writing a script and in the usage() function I want to specify the usage. My script uses either option1 or option2 or both. One of them is mandatory. Is there a standard way to write it up?
17
votes
2answers
1k views

What does `:-` mean in a shell script

I saw this in the end of an awesome shell script but I can't understand the login here because I think it's being short-handed for a longer command. spark ${@:-`cat`} This apears at the end of this ...
3
votes
2answers
994 views

Getopts option processing, Is it possible to add a non hyphenated [FILE]?

I'm using getopts for all of my scripts that require advanced option parsing, and It's worked great with dash. I'm familiar with the standard basic getopts usage, consisting of [-x] and [-x OPTION]. ...
8
votes
3answers
5k views

Transform an array into arguments of a command?

I have an array of "options" of a command. my_array=(option1 option2 option3) I want to call this command in a bash script, using the values from array as options. So, command $(some magic here ...
21
votes
2answers
32k views

How to check if there are no parameters provided to a command?

How do you check if $* is empty? In other words, how to check if there were no arguments provided to a command?
5
votes
4answers
519 views

How can I create a empty file whose name begins with a dash? [duplicate]

How can we create a empty file with the unix name -stuff. It means the name start with -. I tried with touch -stuff but it didn't work.
17
votes
1answer
607 views

How do ${0##*/} and ${0%/*} work?

I'm quite confused about the following regular expressions I found in a shell script: ${0##*/} ${0%/*} How do they work?
2
votes
3answers
390 views

How to substitute awk argument?

I want simplify awk command for common usage so instead of writing awk '{print "rm -r"$4 }' each time I want to write myawk "rm -r"$4. I've tried to write such function myawk() { awk '{ print $1 }' ...
11
votes
7answers
6k views

Print shell arguments in reverse order

I am a bit stuck. My task is to print the arguments to my script in reverse order except the third and fourth. What I have is this code: #!/bin/bash i=$# for arg in "$@" do case $i in ...
3
votes
3answers
4k views

How to pass a string parameter on bash function?

I have this code that does work: get_parameter () { echo "$query" | sed -n 's/^.*name=\([^&]*\).*$/\1/p' | sed "s/%20/ /g" } But I want to replace the "name" with the parameter that I pass ...
3
votes
1answer
403 views

How to unset the positional parameters?

How do I do this: set foo bar baz unset # Something else here echo $# # Should ouput 0 By doing set "", $# will still be 1 and not 0.
13
votes
2answers
2k views

How to safely pass variables to root-enabled scripts?

This question is totally general and not only applicable to my situation, but... I have a small busybox appliance where I want a non-root user to be able to execute a particular script with root ...
4
votes
2answers
3k views

How to escape < or > in a parameter in shell?

I'd like to use grep with a PCRE expression that contains the < character. Bash thinks I want to redirect, but I don't want to. How can I escape <?
2
votes
2answers
510 views

Want a seperate file to store mysql username, password, and database name

I have as script that dumps a mysql database, and compresses the file. What I want to do is have another (edit) file which can change the username, password and database name. Then somehow connecting ...
5
votes
2answers
840 views

Documentation of kernel parameters

Where can I find a technical description of the kernel parameters listed in /proc/sys (ob Linux)?
7
votes
5answers
2k views

Indexing and modifying Bash parameter array $@

Is it possible to refer to indexes in $@? I can't find any reference to use like the following anywhere in GrayCat's wiki, and the Advanced Scripting Guide and others assign this to a different ...
30
votes
3answers
9k views

How to pass parameters to an alias?

For bash script, I can use "$@" to access arguments. What's the equivalent when I use an alias?
9
votes
3answers
9k views

How do I split the $0 variable to find directory and relative paths in bash?

The $0 variable contains the path info of the script. How can I change the path info to absolute path? I mean how to process ~, ., .. or similar? How can I split the path info into directory and ...