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0
votes
2answers
37 views

Bash Script execute command as user

I'm just wondering if it's possible to execute a command inside a bash script as a specified user and supply the password in one string. At the moment I have COMMAND="${DIRECTORY}/script.sh" su -c ...
1
vote
2answers
33 views

How do I keep command options from breaking other scripts executed within my command?

I have a bash shell script(my_script.sh) which runs a script(their_script) during execution. My script (my_script.sh) looks like this : THISDIR=`dirname $(readlink -f $0)` main() { cd $THISDIR ...
1
vote
1answer
50 views

Can a bash array be used in place of eval set — “$params”?

I'm taking a look at the optparse library for bash option parsing, specifically this bit in the generated code: params="" while [ $# -ne 0 ]; do param="$1" shift case "$param" in ...
1
vote
1answer
33 views

Difference between “-” and “--” prefixed command line parameters? [duplicate]

Scripts on command line offer a wide range of parameters types. Often parameters can be passed to the script via "--[parameter]" or "-[parameter]". But what is the difference? Why do some parameters ...
8
votes
1answer
230 views

Bash alias with a space as a part of the command

I'm trying to create a bash alias, where the alias itself has a space in it. The idea is that the alias (i.e. con) stands for sudo openvpn --config /path/to/my/openvpn/configs/. Which results in a ...
6
votes
2answers
254 views

Count number of elements in bash array, where the name of the array is dynamic (i.e. stored in a variable)

Brief statement of the question: Is there built-in bash method to count number of elements in bash array, where the name of the array is dynamic (i.e. stored in a variable), without resorting to ...
1
vote
0answers
28 views

Nested parameter expansion [duplicate]

I know how to use ${parameter#word} Remove matching prefix pattern and ${parameter%word} Remove matching suffix pattern. but is there a way to nest them in a single call, such as ...
1
vote
0answers
36 views

How to combine many multitail parameters?

The .multitailrc file contains a color scheme called amir_log, which I load using multitail -cS amir_log ~/wildfly/wildfly-8.2.1.Final/standalone/log/server.log But there are ANSI color codes being ...
3
votes
5answers
123 views

bash iterate file list, except when empty

I thought this would be simple - but it is proving more complex than I expected. I want to iterate through all the files of a particular type in a directory, so I write this: #!/bin/bash for fname ...
14
votes
2answers
587 views

Does parameter order matter with tar? [duplicate]

I am learning Linux. I was surprised to see that the parameter order seems to matter when making a tarball. tar -cfvz casual.tar.gz snapback.txt bucket.txt gives the error: tar: casual.tar.gz: ...
4
votes
1answer
153 views

What does this line in bash do? Parameter-||scriptname

I've been reading through the bash man page, and reading through scripts on my system (CentOS 6.7), looking up things in the bash man page as I go. It's a great exercise; I learned, for instance, how ...
0
votes
1answer
48 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 ...
-1
votes
1answer
68 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 ...
1
vote
1answer
67 views

Which are (bash) shell special parameters?

I've found some special parameter with bash starting with $ sign. Example: When I was wandering for exit status I knew about $?, process ID by $$ etc. So, I am sharing this post to know Which are ...
2
votes
2answers
88 views

print empty line in sed output when passing multiple filenames

I'm doing some placeholder replacements in various files that I'm feeding to ldapadd, to add new entries to an LDAP directory: sed \ -e 's/%%FOO%%/whatever/g' \ -e 's/%%BAR%%/other thing/g \ ...
13
votes
2answers
748 views

Correct behavior of EXIT and ERR traps when using `set -eu`

I'm observing some weird behavior when using set -e (errexit), set -u (nounset) along with ERR and EXIT traps. They seem related, so putting them into one question seems reasonably. 1) set -u does ...
0
votes
2answers
43 views

Issue on awk input parameter in ksh

I am running this script: INPUTNAME=ABC.XYZ FILENAME="Sample.xml" awk -v inputName=$INPUTNAME ' /<machine.*name=/ { f=1 ; m=0 ; res="" } f { res = res $0 ORS } f && ...
1
vote
0answers
96 views

Disk configuration options, what can affect performance

I have 2 disks, the same model and vendor, first one , probably performs faster. We do write into multiple files. Can you compare 2 configurations and tell what can affect performance? 1. (faster) ...
1
vote
1answer
103 views

find with -exec eval of $0 [duplicate]

In the following command I would like to know why $0 was evaluated to the file found by find and not the echo command. $ find . -type f -perm -u=x -exec bash -c ' /bin/echo $0 is the name of the ...
0
votes
0answers
25 views

Automated function Logging tool

Is there a automated tool for logging function name , function entry and exit parameters per thread for complex multi threaded application.(C / C++)
0
votes
3answers
92 views

Bash: Access parameter passed to last command [duplicate]

This is a situation I often find myself in: mkdir /Some/really/long/path/to/a/directory/ cd /Some/really/long/path/to/a/directory/ I know that ideally you would cd /Some/...etc.../a/ and then mkdir ...
1
vote
0answers
222 views

isolcpus doesn't work on Ubuntu 14

I added isolcpus=0 to the end of the following line to the file /etc/default/grub GRUB_CMDLINE_LINUX_DEFAULT="quiet splash isolcpus=0" The idea, as I understand it, is to reserve core 0 from having ...
0
votes
2answers
244 views

What is the variable of $#?

I'm learning introductory Linux and came across something which I did not understand: "The following command has been executed: set 10 20 30 40 50 Enter the value of the variable $#: I understand ...
2
votes
2answers
173 views

An error of variable type?

I've an error that I don't understand, it seems that that the problem is that my parameters into the shell are not of the same type as what they are in my SQL Database. For a better understanding: ...
1
vote
2answers
292 views

How to put $@ in quotes?

My bash script looks like this: #!/bin/bash grep -r --color=always $@ . | nolong The file is saved in /usr/bin/findstr Everything's ok when I run this: findstr hello But when I run this: ...
0
votes
0answers
110 views

Gummiboot Kernel Parameters, Cannot find /boot/loader dir

I installed Gummi boot to my EUEFI partition which is sda1. when I do lsblk it show boot is mounted on sda2, which is also my root partition. when I ls '/boot' there is no loader dir. I need the ...
2
votes
1answer
210 views

Bash - Split quoted parameters

I have a script which gets called with two parameters: ./script.sh a b I'm currently reading them through $1 and $2 (such as cd $1). My problem is that the output needs to be the same for when the ...
0
votes
2answers
8k views

Convert input string to date in shell script

My shell script: #!/bin/bash echo "$1"; startd=$(date -d "$1" +"%Y%m%d"); echo "$startd"; My command: sudo ./test.sh "20151010" The output: 20151010 20150213 it printed todays date ...
2
votes
3answers
288 views

How can I pass on parameters 4..99 to another function

I'm calling a function and I want to pass up to 100 paramters onto another function. I do not want to pass on the first 3 params, I start with param4 being the first param for the other program. I ...
2
votes
3answers
1k views

How to pass an array to a function as an actual parameter rather than a global variable

Is there a way to pass an array to a function as one of its parameters? Currently I have #!/bin/bash highest_3 () { number_under_test=(${array[@]}) max_of_3=0 for ((i = 0; ...
1
vote
3answers
59 views

How to access the contents of a file that is used as an argument when running a bash script?

I am running a bash script with its parameters/arguments as files. From inside the script, how do I get the contents of those files? I run the script with this command line: sh script_name ...
2
votes
2answers
603 views

Print file name extension using -exec in find

I am playing around with -exec flag of find command. I am trying to use the flag to print the extension name of files, using a fairly new Linux distribution release. Starting simple, this works: ...
4
votes
3answers
1k views

How to pass the content of a file as multiple arguments in bash

I have a file that contains data that gets updated over time (mydata). The file looks like this: 1 2 3 With this file, I want to do this (basically handle each number as a separate parameter): ...
2
votes
1answer
153 views

how handle a path ($1)

I've: /home/wms/mp3/ and /home/wms/tmp/ Inside ~/tmp my script: #!/bin/bash br=64 for a in "$1"*.mp3 ; do ffmpeg -i "$a" -ar 44100 -ab $br "$br""_tmp/${a%.*} ["$br"].mp3" ; done I do: ...
1
vote
2answers
270 views

Bash script loop to grow parameters

I want to use whiptail to generate a checkbox list based on the output from another program. Only the first word on each line of the output from the first program is necessary, so I extract it using ...
14
votes
4answers
2k views

What does echo $-1 display?

What does the output of echo $-1, echo $-2, echo $-3.. mean? On one of my Linux boxes, it shows me: echo $-1 imsBEl1 echo $-2 imsBEl2 And on another Linux box, it shows: echo $-1 himBH1 echo $-2 ...
13
votes
2answers
660 views

When running a shell script, is it possible to pass specific positional parameters without having to enter them all in order?

For example, if I have script ./foo that takes 10 parameters, and I only want to pass the 8th parameter. The only way I know how to do this currently is: ./foo '' '' '' '' '' '' '' 'bar' Is there ...
1
vote
2answers
151 views

Shell syntax question with difficult parameter expansion

I am scratching my head to understand this script and can certainly use some expert advice. getopt_simple() { echo "getopt_simple()" echo "Parameters are '$*'" until [ -z "$1" ] do ...
2
votes
1answer
104 views

Parameter substitution and error messages: suppressing line numbers etc

Here is my example file: !/bin/bash # argument-one # Is first argument missing? # First method [[ "$1" == "" ]] && echo "Usage: $(basename $0) filename"; exit 1 # Second method # ...
8
votes
2answers
807 views

Is it possible to use shell parameter variables ($1, …, $@) directly in CLI?

Sometimes it is necessary to emulate and verify the above variables in small examples and then can be copied immediately to some script, etc. I tried to solve by using a simple example in the ...
0
votes
1answer
85 views

Special Parameter query - multiple used to obtain command name? [duplicate]

In a uni text provided us to cover bash scripting, the following variable assignment has got be stumped and I've yet to get an answer back from anyone, hence hopefully someone on here can help. ...
3
votes
1answer
76 views

Customize bash to always include a certain parameter

When using the "ls" command, bash prints in the following format: file1 file2 file3 file4 file5 file6 file7 file8 But when given the parameter "-1", it prints: file1 file2 file3 etc... Is there ...
2
votes
2answers
706 views

What is the bash syntax for extracting the values from multiple instances of the same argument?

I want to use multiple instances of command line paramater such as the -d option used by PHP for passing PHP options. I am currently using the getopts command in bash. With PHP invocation it would ...
1
vote
1answer
2k views

What's the right way to set Linux kernel runtime parameters?

What's the prescribed way to set Linux kernel runtime parameters? I've seen sometimes that people will set these in files such as /etc/rc.local. Is this really the right way to do this?
1
vote
1answer
3k views

Permanently set kernel parameters [isolcpus] without grub?

Is there any way to set kernel parameters in an Ubuntu-based system without relying on grub? (not available in the target environment) Specifically I want to set the isolcpus parameter to dedicate ...
5
votes
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 ...
0
votes
1answer
220 views

How can I pass in a parameter to sed?

To be more precise - how can I pass in a parameter to a program that then calls sed - how can I 'pass' that parameter along? I have a file 'source_code.sc'. I have a sed script "find_expect": #n ...
2
votes
1answer
158 views

How to manipulate all parameters of a shell script at once?

While for a finite amount of parameters one can explicitly do something like wrapped_function "${1#prefix}" "${2#prefix}" "${3#prefix}" # etc., isn't there a simpler way to manipulate all ...
12
votes
0answers
358 views

Should I use $* or $@? [duplicate]

Which one of $* or $@ is better to use (in array syntax,command line parameters, etc.) to avoid any bugs/problems in code? Or it does not make any difference?
2
votes
1answer
2k views

Execute command supplied by function parameters

I'm trying to create a function method in a bash script that executes a command which is supplied to the method by the paramters. Meaning somethings like this: special_execute() { # Some code ...