Questions about bash only, as opposed to other Bourne/POSIX shells. For all Bourne/POSIX-style shells, use the /shell tag instead.

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1
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2answers
65 views

Search for matching files with wildcards without using find in a bash script

For an assignment, I'm supposed to write a bash script that can act as a very basic find, but without actually using the find command. For example, if I put in this input: my_find ~/homedir/ -name ...
7
votes
4answers
189 views

Matching and pasting to line

So I have 2 very big text files, consisting of lines like so: First: Robert:Dillain:Other:Other:Other Julian:Brude:Other:Other:Other Megan:Flikk:Other:Other:Other Samantha:Minot:Other:Other:Other ...
0
votes
1answer
30 views

How can I multiply a column by a variable and write out? [duplicate]

I would like to multiply a single column in a .txt file by a variable and then write to another .txt file. What am I missing from the awk line? Appreciate any help in advance. !/bin/bash ...
2
votes
1answer
35 views

Can we use two brace expansions together?

For example, I want to rename a file abc to bd. Why doesn't two brace expansions work? How shall I make brace expansion work in my example? Thanks. $ touch abc $ mv {a,}b{c,d} mv: target `bd' is not ...
6
votes
7answers
2k views

Is there a unix command that gives the maximum of two numbers?

I was looking for a command to limit numbers read in from stdin. I wrote a little script for that purpose (critique is welcome), but I was wondering if there was not a standard command for this, ...
1
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0answers
33 views

How do you derive a decimal from a math operation involving a variable?

I'm trying to find derive SCALEFACTOR which is basically 10000/(sum of 4th column in a file). How do I get a decimal from the output? Appreciate any help in advance. #!/bin/bash ...
1
vote
1answer
36 views

Why scripts run as user but not as a cron?

I have a script that checks to see if port 4000 is open and listening, if it is return true, else start a service that also outputs a logfile. The script runs fine if I execute it as a user, but if I ...
1
vote
2answers
41 views

How do I find folders containing no recently modified files?

I have a directory that gets a lot of data dumped into it, and I want to find all directories whose contents haven't been modified recently (e.g., in the last 5 days). I'm trying to compose a call to ...
3
votes
3answers
54 views

Is there any way to keep track of all the processes exec'd by bash

I'd like to be able to keep statistics on which programs I run the most through bash. Is there any way to insert some sort of hook into bash so that it logs everything it execs? Note that looking ...
1
vote
2answers
93 views

for loop when matching both front and back of file name

I'm trying to set up a for loop to run a process on pairs of files. The names of the files look like this 36_002_CGATGT_L001_R1_005.fastq.gz 36_002_CGATGT_L001_R2_005.fastq.gz ...
1
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2answers
15 views

Linux copy range of folders

I found this link with an example of how i can actually copy range of files Copy a range of files in command line (ZSH/BASH), using this $cp P10802[75-83].JPG ~/Images/. Is there any way i can also ...
1
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3answers
68 views

How do you parse through a subdirectory where the path contains spaces? [duplicate]

I'm trying to parse through a set of files in a directory on a mapped drive. However, I can't seem to resolve an issue that seems to be because of spaces in the path to the subdirectory. Would ...
0
votes
1answer
23 views

how to change several piece of html code

I have several chunks of html code ,see below, in a html page that I need to change Assurez-vous de bien recevoir tous nos messages en ajoutant bebeco@concretisezvosprojets.com à votre carnet ...
0
votes
2answers
30 views

A batch that cout the number of occurrences

I've to extract the number of words using each letter of the alphabet from A to Z. The script that i've to create create take as parameter the name of the dictionary file to analyze and will be used ...
-3
votes
0answers
23 views

How to configure the Shell if no .bashrc exist ?

I have a problem with my Xfce Terminal, once I start it it does not respond for a minute. I was told here to change settings in the .bashrc configuration file. Unfortunately no such file exist. What ...
1
vote
1answer
25 views

How do I control output after executing a command?

.. Script Run Complete. You have new mail in /var/spool/mail/<user-name> -bash-3.2$ I have seen the above message most the times on my prompt, probably while it's idle or as soon as script ...
1
vote
2answers
70 views

Is there any way to make scripts dynamic? [closed]

I need my script to show the time till next run, continuously like a timer, is this possible?
-3
votes
0answers
20 views

How can I use multithreading in unix by considering its core's and cpu's? [closed]

I actually designed a unix script for automate the backup and i used multithreading concept to make multiple gtar command to run simultaneously by getting the thread value in run time. My script is ...
1
vote
3answers
51 views

how to express line feed in shell?

Im my debian7.8 bash shell. str="deb http://ftp.cn.debian.org/debian/ wheezy main contrib non-free \n deb-src http://ftp.cn.debian.org/debian/ wheezy main contrib non-free " echo $str > ...
2
votes
1answer
51 views

Bash script to detect uploaded files triggers many times for one file

I have a simple bash script setup that uses the built-in inotify daemon running CentOS 6.6. The script will simply echo the file that is upload to a specific directory. The script works but it echos ...
0
votes
0answers
17 views

Possible to pass env vars into chpst without envdir?

I use runit to daemonize my web application, and I'm trying to see if I can have my process managed by sv not have to have a corresponding envdir for its environment variables. I wonder if I can just ...
3
votes
1answer
125 views

Can the command completion for `cd` be modfiied to only show directories and ignore files?

When I am in a directory in bash, and I press cd Space Tab, it shows everything in the directory as a possibility. (Show all 1000 possibilities?) This is really cumbersome when I am in a directory ...
0
votes
0answers
51 views

Bash script not executing when called from another start with “at command”

First, I understand this is probably something better suited for cron. However, I don't have access to cron. (shop rule around here) So, I am using the next best scheduling option at my disposal. ...
1
vote
1answer
16 views

Tmux - Get number of panes in the current window in bash variable?

I'm scripting Tmux, and would like to know the number of panes in the current window from a bash script. Is there anyway to find out this information? in pseudo code, i'd like something like this: ...
0
votes
1answer
20 views

tail-ing a filename that is a date [duplicate]

I am creating a logfile from kermit named the current date (which is in the format of DD MMM YYYY - which can not be changed AFAIK), and using the file name as today's date. I then have a Bash script ...
0
votes
2answers
53 views

help with bash scripting tput getting errors [closed]

I am a beginner to bash scripting. I need help to figure out what is wrong with this tput menu. #!/bin/bash tput setb 3 tput clear function main_menu { option=0 until [ "$option" = "4" ]; do echo ...
0
votes
1answer
60 views

bash if, then and else statement

I am learning bash, I ran into a small problem when trying to write a small script #!/bin/bash clear read num if [ "$num" -eq 2 ] then [ -d "/etc/passwd" ] | sudo cp /etc/passwd /home echo ...
1
vote
1answer
27 views

how to list downloaded apt packages without dependecies

I'm trying to get the names of downloaded packages without dependencies.. I don't want to get all the files in /var/cache/apt/archives .. I only want to get the primary packages without dependencies I ...
2
votes
1answer
66 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 ...
3
votes
3answers
171 views

How to match * with hidden files inside a directory

How to match the hidden files inside the given directories for example If I give the below command it's not giving the result of the hidden files, du -b maybehere*/* how to achieve this ...
2
votes
2answers
112 views

Bash menu with multiple parameters in one row

I have searched a couple of days and still didn't found the answer. I hope that you can point me in right direction. I would like to know how to write a bash script with a options, that can be ...
1
vote
1answer
65 views

bash $(printf “%s\n”) does not create multiline

I created shell script, that logs into FTP server and renames some directories. I put FTP commands in multiline string like so # !/bin/sh ftp -inv $HOST << EOF user $USER $PASSWORD $COMMANDS ...
0
votes
0answers
23 views

how to run bash script from isolinux.cfg

I've been trying to add an entry to a bash script to my custom cd boot menu.. So I've tried to edit isolinux.cfg and load it instead of kernel but didn't work.. Any ideas??
3
votes
1answer
139 views

eval limitation with piped commands

We have a shell script that builds a long piped command chain in a variable and executes it with eval (the following code is simplified to the essential): cmd="cat /some/files | grep -v \"this\" | ...
8
votes
2answers
145 views

Why does bash ignore SIGTERM?

Sometimes when I want to logout quickly I do kill -15 -1. I've noticed that bash is ignoring SIGTERM. I wonder what's the rationale for such bash behavior? It's not very UNIX'y to ignore SIGTERM ...
1
vote
3answers
37 views

Find files based on modified date(specifying the exact hour) [duplicate]

My question is: How to find files that has been modified from a given date(specifying the exact hour) to another given date(specifying the exact hour) in a given directory, from / for example. I ...
1
vote
2answers
41 views

How to format decimal number to display the preciding zero but not the trailing ones?

I have the following script on Ubuntu 14.04.1 LTS 64-bit bash command prompt: S=0.030 F=0.150 N=10 reso=20 DIFF=`echo "scale=3; $F - $S" | bc -l` df=`echo "scale=3; $DIFF / $N" | bc -l` is=`echo ...
2
votes
2answers
50 views

menu script over ssh

I have a script that asks for input from the user. When I run this locally it does what I want however I'd really like to run it over ssh. I've tried the regular ways I'd run a script: ssh ...
0
votes
0answers
59 views

Creating an excel spreadsheet with CronTab

I would like to create a spreadsheet (I will acquire will be the timestamp, engine_hours_value, and power_cycle_value) in excel with datum acquired from the Unix terminal. This data will be put on to ...
6
votes
4answers
502 views

Why is it “while kill -0 $PID” and not “until kill -0 $PID”?

I may be being daft here, but if I want to do something while a process is running, why do I do: while kill -0 $PID do #... done instead of until kill -0 $PID do #... done ? kill -0 ...
2
votes
3answers
41 views

Controlling the environ passed to child process by bash

I am using x86_64 GNU/Linux with bash #include <stdio.h> #include <stdlib.h> int main(int argc, char **argv) { system("set > setc"); // A subset of `$ ...
1
vote
1answer
49 views

Bash script and yml file output

I'm trying to catch the stdout of a script to a file, and at the same time have it display its ongoing summary: ./RUN host-names ANSIBLE.yml 2>&1 | tee out.txt What this does is that it ...
1
vote
3answers
40 views

How to convert bash shell script to Markdown?

Imagine one has been working on a bunch of deploy scripts. These shells scripts are heavily documented with comments and links and are meant to be read by humans. Wouldn't it be handy to convert ...
14
votes
4answers
602 views

What is the difference between '$ . foo' and '$ ./foo'? [duplicate]

t is a simple script What is different between two case below : $ . t and $ ./t
1
vote
1answer
88 views

How to delete file called “-C” [duplicate]

I need to delete the following file which I managed to create with bunzip2: -rw-r--r-- 1 beginner group 67493376 Feb 17 17:30 -C The following don't work rm -rf '-C' rm -rf "-C" My OS is ...
0
votes
1answer
36 views

bash: getting integer expression expected

Here is the piece of code that gives the problem: if [ " ls -l ~/sysbackups | wc -l " -gt 5] What to do?
0
votes
1answer
51 views

Run a Vim command from a bash script

This is related to a question I asked earlier but I would like to keep it separate in case anyone else can find use in it. I have a command that I am running on a file called dummy.out from the ...
2
votes
2answers
47 views

Bash command: is it possible to pass an argument before a custom command (function) or it must be only after:

I am wondering if it is possible to pass an argument to a custom command before the command? Let say I have custom command ping and I would like to pass the IP address before command: instead ping ...
1
vote
1answer
44 views

I want to create a cron job that runs a command on a remote linux box using ssh but I want ssh to answer password [duplicate]

Thank you for the reply.This is not what I am after. The ssh from server 0 to (1,2,3) (no password) but a remote script on server (1,2 & 4 ) which starts a service/application needs a password for ...
0
votes
2answers
21 views

Ubuntu CentOS RHEL cross bash script su support

I know that title was a little ambiguous. Allow me to explain our issue. We designed an installer script on Ubuntu since Debian based systems are our primary core, however, some of our cloud based ...