Questions about shell scripts, executable files that are interpreted by a shell (bash, zsh, etc.).

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1answer
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Pattern matching

I am trying to follow Bash Cookbook to learn about Bash Scripting. I am on example 6.8 Testing with Regular Expression. I have the following script: #!/usr/bin/env bash # cookbook filename: ...
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0answers
8 views

bash scipt does not compare file names with [ and ] correctly

I have a bash script that deals with files. It finds all the files in one directory and searches for the name of each in another directory. For that it uses "${myfiletobesearched}" inside the ...
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2answers
14 views

Simple Bash server usign netcat and authorization required

Running a simple server in bash: echo -ne 'HTTP/1.0 200 OK\r\n\r\n'; cat page.sh | nc -l -p 8080 The script page.sh generates website. It works and meets my expectations. Is there a possibility of ...
0
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1answer
15 views

mv command with path wildcard containing random string

Im trying to move a file to a path which has a random string that I cannot know in advance ~/.config/foldername/45fhiu84.dev-edition/subfolder/ I have tried mv ~/Downloads/myfile.txt ...
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1answer
24 views

Can all of fork(), exec() and system() be wrong? [on hold]

I understand why it could be less than best practice if I write C code that executes shell commands by calling system() and that it's better to use exec and fork but then a very experienced C ...
2
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3answers
62 views

Replace values in file

I have a files: $cat file1.txt 1234|W 1345|S 8427|D 2132|C 3243|V and my sql file is : $cat select.sql SELECT * FROM CUSTOMERS WHERE ID IN (FLAG); and I have a shell with the next ...
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2answers
27 views

Can we install a package through a shell script? [duplicate]

I'm trying to write a shell script so that when I reinstall my Ubuntu again. I could just run script and retain all the packages. And I'm planning to pass password in form of argument. My question ...
0
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1answer
24 views

Script for connection with ssh then command once connected

I need to write a script that connects to a remote server, then once connected, connects from there to another server, then changes directory. The following of course does not work (it connects to ...
1
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1answer
48 views

Needed shell script modification to show IP and host DD-WRT

I am running DD-WRT v.3.0 on my Linksys EA6500 router and I have the following script running in order to give me access to the WiFi MAC address that are currently connected to the router: echo ...
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0answers
16 views

Bash terminal shows different outputs

#!/bin/bash ionic serve &> temp.txt this code inside a script always produces the same output, ie, same output written to temp.txt file. But if I run ionic serve &> temp.txt in a ...
4
votes
1answer
823 views

KSH styling text based menu using STDERR

Is it possible to format the STDERR in order to have a better looking menu using the select command? I have a simple select select oChoice in $(<tempMenu.menu) ; do case "$oChoice" in ...
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0answers
26 views

Insert the environment path to script file to read [on hold]

I have a text file which has user input i.e LD_LIBRARY_PATH. I want to add the that library path environment text into the script file (/etc/init.d/scriptfilename). Will it be possible?
2
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1answer
30 views

Create table with frequency of unique names retrieved from multiple .csv files

I have 32 CSV files containing fetched information from a database. I need to make a frequency table in TSV/CSV format, where the names of the rows are the name of each file, and the names of the ...
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votes
2answers
32 views

Linux Bash script fails with a syntax error

Trying to get this bash script to work: #!/bin/bash for result in $(cat ./fn7); for dip1 in $(cat ./fn4); for dip2 in $(cat ./fn5); for dip3 in $(cat ./fn6); for ip in $(seq 0 255); ifconfig > ...
2
votes
3answers
2k views

Update process name in shell, is it possible?

In C/C++ it is in general possible to do strcpy(argv[0], "new process name"). It's a hack used in malicous software to hide real process name. Is such operation possible via shell? What I want to do ...
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0answers
34 views

Run sh script at system startup - Red Hat 7.2

I searched the Internet but there are too much different opinions about this issue. I have two scripts to run. One to run at system startup (not at system reboot as I read in some posts) and another ...
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0answers
20 views

Bash Script problem with Variables from files [duplicate]

Trying to get this script to work how ever I get an error no matter how I try to set the varibles. After checking the varibles are not being set from the files that the information is in.
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3answers
20k views

How can I remove an element from an array completely?

unset array[0] removes the element but still if I do echo ${array[0]} I get a null value moreover there are other ways of doing this but if an element of an array contains spaces like below ...
2
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4answers
29 views

How to catch and handle nonzero exit status within a Bash function?

Say I have the following (pointless) Bash function: myfunc() { ls failfailfail uptime } I run it as follows: myfunc || echo "Something is wrong." What I want to happen is ls runs (as ...
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0answers
18 views

I'm able Start Service With init.d script, however doing service <service name> start does not work

I'm able to start a service with an init.d script, however doing service <service name> start does not work. For e.g. /etc/init.d/haskal start, the service is starting fine and service haskal ...
0
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1answer
48 views

Running .sh Script With Sudo Results In Different Output

I'm seeing some really strange behavior in a script I'm working on.What I have is an svn hook that gets run whenever a commit is made to an svn repo. It runs a sqsh command that generates another ...
0
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1answer
26 views

unzip without replacing original file and report to log

I want to write a bash script to decompress a file without overwriting the original one and redirect the operation result into a log file. I found an answer to the first part of my question at: How ...
0
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0answers
12 views

Delay in writing hexdump data to a file

I have a script which does hexdump along with pipeline commands and finally I am redirecting it to a file. Now I am logging data from the serial port of my Raspberry Pi. The data is received with a ...
0
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1answer
30 views

command /opt/bin/date --date '-15 minutes 2016-04-27T14:14:47' producing result many hours before stated time

I'm using the following command in an attempt to work out the time 15 minutes before the timestamp: /opt/bin/date --date "-15 minutes 2016-04-28T16:58:55" '+%Y-%m-%dT%H:%I:%S' The problem is the ...
2
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1answer
32 views

How do I check for the existence of a process without a failed exit code being returned?

I’m using Amazon Linux. I want to start a process provided one isn’t running already. This is a bash script I embed within a Jenkins Maven job. So I have pids=$(pidof /usr/bin/Xvfb) if [ ! -n ...
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1answer
23 views

cannot get screen command to execute code containing DISPLAY=:0

I am trying to ssh into a remote machine and run a shell script, which opens a GUI. I want the GUI to open on the remote machine and remain open (so I am using DISPLAY=:0 nohup). I tried: ssh -t ...
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1answer
8 views

Setting XDG_CACHE_HOME Breaks Firefox Installation

In my .bashrc I set my XDG_CACHE_HOME variable to "~/.cache/". This breaks my Firefox installation, telling me that it cannot load my profile. Without this line, Firefox loads properly. I have ...
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1answer
16 views

shellscript is having trouble finding a file [duplicate]

I have a shellscript that is having trouble finding a file. The text file exists so I don't understand what the issue is. #!/bin/ksh goodmain $1 | sed -e '1,/mmxxaa/d' $ ls -l total 1364 ...
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6answers
47k views

#!/bin/bash - no such file or directory

I've created a bash script but when I try to execute it, I get #!/bin/bash no such file or directory I need to run the command: bash script.sh for it to work. How can I fix this?
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2answers
17 views

How to fix vmware header error?

I'm trying to run vmware on my kali linux 2.0 box, because I want a lab to practice my skills on, but vmware won't launch it's giving my an error message saying "C header files matching your running ...
0
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1answer
32 views

If else statement involving two numbers in scientific notation [duplicate]

I have two numbers in scientific notation and I want to do some comparison between them in an if statement in bash. While doing so, I am getting error like bwlow: E.g: bash-4.2$ a=10e-12 bash-4.2$ ...
1
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1answer
38 views

Aligning Hexdump Data in a Specific format?

I am reading serial data from my Raspberry Pi and all I am doing is a Hexdump I have to find the header and then go to the 2nd byte of data from header for ex: ed 13 74, I have to take the value 4 , ...
1
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1answer
24 views

Escape strings to be posted via curl

I am trying to make a script that takes some atom feeds and posts them to slack through the Slack API via curl. What I have now works for simple texts, but some of them have double quotes or & ...
1
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2answers
29 views

loop create from file

I have a file(test) It contains two columns and two lines pippo mm pluto tt I would like to create directory,owner and create password I do some think like that while IFS= read a b; do mkdir ...
0
votes
1answer
23 views

Correct syntax for inputting date variable into date calculation code

In my script, the following code successfully produces a timestamp variable for $n in the format 2016-04-28T15:47:48 for n in $(perl parsetime.pl | sed "s/.....$//") do echo $n result is: ...
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3answers
39 views

how can we use multiple variables in single for loop in shell script?

I am implementing as below code using for loop but wrong output coming after running the script. for i in `awk -F"|" '{print $1}' $INPUTFILE`, j in `awk -F"|" '{print $2}' $INPUTFILE` do echo $i:$j ...
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votes
1answer
33 views

add multiple .csv files using bash command

I want to iterate over all randomly generated CSV files in a folder using using bash and add them line by line. Each CSV files has 3 rows, the 1st row indicates just the number of generated files and ...
1
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1answer
45 views

BASH Variable checker function

I am struggling to figure out a way to reduce code duplication. Specifically when checking if a variable is set. My code currently looks like this: # webadmin enabled if [ -f "${servercfgfullpath}" ...
0
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1answer
20 views

printf in my output now

The encryption on this problem just got more interesting. I started with this script: while read CTFlist; do #next we need to create ctfs padded with zeros as a variable ctfPadded=(printf ...
1
vote
4answers
4k views

Trouble with read line script in Cygwin

I'm on windows 7 using Cygwin. My script and text file are located in the same directory. #!/bin/bash while read name; do echo "Name read from file - $name" done < /home/Matt/servers.txt I get ...
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2answers
42 views

sed substitution

I have a string as follows: /test/test/ 12 /test/test My goal is to turn it into: /test/est/ 12 /test/test This is the command: echo "$x" | sed 's@\(/*/\).@\1@g'" I am using at the moment but ...
0
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1answer
18 views

Including milliseconds in a Script?

sudo hexdump -v -e '1/1 "%02x\n"' /dev/ttyUSB0 | awk '$1=="ed" { getline byte1 getline byte2 number = strtonum("0x" substr(byte2,2,1))+2 ...
0
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1answer
20 views

Dynamically write bash script from another?

I am trying to dynamically create and write to a file a bash script from from a current bash script. echo "## Get the IP of the system that was assigned #!/bin/bash ip=$( hostname -i | xargs ) echo ...
2
votes
3answers
450 views

command not found and syntax error near unexpected token

I have this script to divide a file over a 100000 or even more in 50000 lines. desc() { echo ...
2
votes
4answers
4k views

Error: ambiguous redirect while transferring output to command

Output to redirect in script: 511@ubuntu:~/Unix/test$ ls -ltr |awk '{print $9}' default.txt dfah.txt fruit.txt fruit_prices.txt dfh.txt header.txt testfile.txt topoutput.txt Script written on shell ...
1
vote
1answer
112 views

check if genisoimage is succesful

I use a script to convert all VIDEO_TS directories to .ISO. How can I check if genisoimage is actually converting it instead of it failling and converting the next folder? After conversion I have a ...
0
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0answers
128 views

Wifi configuration failed while using shell script

I am trying to configure wireless network in a Linux machine using a shell script. In this shell script, first I am scanning for all nearby available wifi networks with respective details. After that ...
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1answer
2k views

Syntax error in bash script: near unexpected token `else' [closed]

#!/bin/bash input="" echo "Does a wall needs to be sent?" read input if [ $input="yes" ]; then echo "Sending message to all users" echo "" else if [ $input="no"]; then exit fi fi echo ...
4
votes
2answers
226 views

Is there a way to have a function in my bash script auto run on any command error?

I'm writing a shell script that needs to do a bunch of commands and every command depends on every previous command. If any command fails the entire script should fail and I call an exit function. I ...
0
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1answer
68 views

A small script about wget

I want to download an image file called mch_aktuell_gross_20141229_79514688.gif (basically a forecast gif) from www.meteoradar.ch Here is my script: #!/bin/bash wget \ --recursive \ ...