2
votes
1answer
42 views

Forward SIGTERM to child in Bash

I have a Bash script, which looks similar to this: #!/bin/bash echo "Doing some initial work...."; /bin/start/main/server --nodaemon Now if the bash shell running the script receives a SIGTERM ...
16
votes
2answers
623 views

Does ~ always equal $HOME

I know this has probably been asked before, but I couldn't find it with Google. Given Linux Kernel No configurations that change $HOME bash Will ~ == $HOME be true?
4
votes
1answer
97 views

Proper way to distribute shell scripts

What is the most proper way to distribute shell scripts, if behaviours of shells can be modified by set and thus are unpredictable? For example, rm *.txt wouldn't be executed as expected on the ...
0
votes
0answers
54 views

Mirrored Linux Commands [on hold]

I've encountered two incidents where commands (or logic flow) is given forward and backwards In bash scripts: if ... fi (use to closed an if-statement) and in GNU/Linux command line: cat; tac (cat ...
1
vote
0answers
15 views

Mirrored Linux Commands [duplicate]

I've encountered two incidents where commands (or logic flow) is given forward and backwards In bash scripts: if ... fi (use to closed an if-statement) and in GNU/Linux command line: cat; tac (cat ...
2
votes
2answers
28 views

I seem to be “losing” this prompt. What is happening?

I ssh into an ubuntu 12.04 cloud server and start a web server like this (w/ bash): $ nohup python tserver.py & [2] 2122 $ nohup: ignoring input and appending output to `nohup.out' After I run ...
0
votes
1answer
35 views

Faillog - unsuccessful login count in Motd

I wish to include a count of failed login attempts whenever a user logs in. I've created: /usr/local/bin/dynmotd which contains #!/bin/bash FAILLOG=`faillog -u` echo -e " $FAILLOG " and ...
3
votes
1answer
62 views

Is there a way to pass a variable from an awk statement to a bash function as an argument? [closed]

I am trying to look a for some specific values from (such as 1 or 4 and 2 or 3) a text file using an awk statement in a bash script. If this value is found in the file (within the awk statement), then ...
1
vote
1answer
52 views

Verify the length of a variable

I've to verify the length of variable read (my script limit to five the characters inserted), I think about something like this: #!/bin/bash read string check=${#string} echo $check if [ $check -ge 5 ...
2
votes
3answers
43 views

Looking for a way turn multiples commands with same parameter into a one liner

I sometimes end up doing things like: Example: from ~/blah $ mkdir ~/test-tmp $ cp * ~/test-tmp $ cd ~/test-tmp using the destination dir 3 times in a row. Isn't there a way to turn these into a ...
4
votes
2answers
59 views

How to redirect stdout to a file and read from the same file simultaneously with another task?

I want to run a task (which takes quite a long time) remotely in Ubuntu Linux Bash via nohup and redirect stdout to a file, e.g.: nohup task > out.txt & From time to time I would like to ...
0
votes
2answers
23 views

concatenate .out files

Can I combined multiple .out files with the cat command in bash or csh? Additionally I want only the header of first file to be concatenated and I was thinking of using the tail function for that. ...
0
votes
1answer
60 views

Bash script question - skip enter key press [duplicate]

Here is a portion of my script: read main_menu case "$main_menu" in "0" ) exit ;; "1" ) cp /etc/bamt/cgminer.conf.X11 /etc/bamt/cgminer.conf; sudo mine restart; ...
3
votes
2answers
101 views

Add arguments to bash -c

Let say that I want to run a command through bash like this: /bin/bash -c "ls -l" According to bash man page, I could also run it like this: # don't process arguments after this one ...
3
votes
2answers
51 views

Getting the current path in .desktop EXEC command

Im trying to make a .desktop file run a .sh which is stored in the same directory as the .desktop. The whole directory needs to be portable and moved from machine to machine. my run script is run.sh ...
2
votes
2answers
109 views

How to force watch to run under bash

The problem is that when watch is executed it runs sh and I get this error: sh: 1: func1: not found here is the code: #!/bin/bash func1(){ echo $1 } export -f func1 watch func1
3
votes
1answer
57 views

find files without extension

Let say I have: foo.txt bar baz.ooo If I use ls -1 !(*.*) then I'll get only bar on the output. Great, now I wish to have same results with find - some find -regex that will do the job. NOTE: ...
1
vote
1answer
22 views

How to slice a text file into several files of 100 lines each? [duplicate]

My question might be quite unclear here. I have a giant text file with values that looks like this 0.00601233 0.000139403 0.000133679 0.000139497 0.000141683 0.000141888 0.000138646 0.000133465 ...
3
votes
1answer
30 views

Why does the read command not take interactive options when run by sh?

I want to download a provisioning script that reads some configuration parameters via read, and execute it: curl http://example.com/provisioning.sh | sh The problem is, that the read command in the ...
10
votes
3answers
591 views

Is there any major difference when comparing a variable as a string or as an int

Out of curiosity, when doing a bash variable comparison (its value being an integer) it's possible to test it against some predefined value either declared as an int or as a string. Sample script: ...
2
votes
0answers
19 views

Running Custom commands in a Terminal Application [duplicate]

I'm running a terminal application in /dev/pts/X terminal that has its own console as:         What I need is to run commands specific to this application but from ...
5
votes
1answer
163 views

Test -n gives unexpected result

I understand test -n <expression> to return false if the expression evaluates to a string length of greater than 0. Why then does the following happen? Macbook:~ echo ${#undeclared_variable} 0 ...
5
votes
3answers
134 views

Combining brace expansion and output redirection

Often, I use parameter expansion on the command-line, such as cp a.{ext1,ext2} which is expands to cp a.ext1 a.ext2 However, in many cases I do not use cp, but another tool, let's call it cat, ...
2
votes
2answers
90 views

Change directory based on a pipeline's output

I want to go to a directory with using filter For example there is a file named this-is-awsome ls | grep this-is-awsome | xargs cd How can I go to a directory with filter?
3
votes
3answers
104 views

Messed up bash.bashrc file, commands not working anymore

Trying installing Java, I tried to add it to the executable path with the line: export PATH=/usr/lib/jvm/jdk1.7.0_60/bin:$PATH in the system-wide /etc/bash.bashrc file. For some reason this ...
4
votes
1answer
89 views

How to make a variable from a subshell available in the parent shell

I've written a quick-and-dirty script to time some reports from a web service: BASE_URL='http://example.com/json/webservice/' FIRST=1 FINAL=10000 for report_code in $(seq 1 $FINAL); do (time -p ...
2
votes
1answer
132 views

What is the difference between filename=${1:-/etc/hosts} and filename=/etc/hosts? [duplicate]

What is the difference between filename=${1:-/etc/hosts} and filename=/etc/hosts? For example: filename=/etc/hosts if [ -r "$filename" ] && [ -s "$filename" ]; then md5sum $filename ...
2
votes
3answers
45 views

Get the last minute dated lines from list

If I have an input file with a list of users and their dates they were last signed in, how can I select with a sort | awk function the last minute lines? The dates are written in a +%H:%M:%S format. ...
0
votes
4answers
124 views

Bash if conditions of variables within intervals

I have some data spread over time intervals, and I want to take some of those data within the time intervals. For example, I have data at times within 1..9, 11..19, etc., and I want to take data ...
1
vote
5answers
87 views

How to copy a file from a remote network to the local desktop

So I used SSH to remotely login to another computer on a network. I have many files that I would like to copy over to my local desktop. I am trying to follow this How-to : However, I think one ...
2
votes
3answers
38 views

Reuse similar flags for multiple commands

Let's say I want to execute several commands with similar flags such as: du -sh / --exclude=/dir1 --exclude=/dir2 --exclude=/dir3/dir4 tar cvf archive / --exclude=dir1 --exclude=dir2 ...
8
votes
2answers
344 views

disable CTRL-D window close in terminator (terminal emulator)

I am often logged in through multiple SSH sessions. To logout from my sessions, I press CTRL+d, until I am back on my local machine. However, sometimes I press once too many, and my terminal exits. ...
7
votes
6answers
721 views

How to read first and last line from cat output?

I have text file. Task - get first and last line from file after $ cat file | grep -E "1|2|3|4" | commandtoprint $ cat file 1 2 3 4 5 Need this without cat output (only 1 and 5). ~$ cat file | ...
5
votes
2answers
170 views

if statement in .bashrc not working correctly

I set up .bashrc to show a long prompt if the terminal is at least 80 characters wide. Otherwise it shows a degraded, smaller prompt. I use an if statement to achieve this: dp_smaller_than=80 if [ ...
2
votes
4answers
119 views

How to initialize an array using awk and bash?

I am trying to store values of the first line of a text file into an array. Here is what I have so far: arr_values=() awk ' NR==1 { for (i=0; i<=NF; i++) ...
5
votes
3answers
315 views

Is there any harm in using variables that aren't set?

Say I have the following code: # Check if the color prompt is enabled and supported on this system if [ -n "$force_color_prompt" ] && [ -x /usr/bin/tput ] && tput setaf 1 ...
7
votes
2answers
221 views

Cannot sum numbers received from stdin using bc

I'm trying to calculate the average entropy of files contained in a folder using: { echo '('; find . -type f -exec entropy {} \; | grep -Eo '[0-9.]+$' | sed -r 's/$/+/g'; echo '0)/'; find . -type f | ...
5
votes
1answer
69 views

Why does `bash -c somecommand` sometimes not leave a bash process?

On an Ubuntu 12.04, with GNU bash, version 4.2.25(1)-release (x86_64-pc-linux-gnu), I tried the following command: $ bash -c 'pstree -s $$' init───sshd───sshd───sshd───bash───pstree $ bash -c 'pstree ...
0
votes
1answer
71 views

Bash Script : Passing a variable to a bash script that contains quotes, single quotes. etc [closed]

lets assume this is the string: 'a',"b" it contains both single and double quotes. how would you pass this to a bash script as a single string ? this is the bash script: #!/bin/bash echo $1 ...
0
votes
2answers
97 views

Running system bash command in PHP script - syntax error: unexpected T_LNUMBER

If anyone can shed some light on my issue that'd be great. Please don't down-vote me; I'm new to the language and the OS itself and I'm trying my best to research before asking questions, so any ...
3
votes
4answers
155 views

How to cut everthing until a specific word / after a find in a script

Hello I try to get the output of files from today wich contains ERROR. I use this to find the files I want: find /home/user/logfilesError/ -maxdepth 1 -type f -name "gandalf_*"\ -daystart -mtime ...
0
votes
2answers
21 views

Finding and replacing text inside awk block

I want to find and replace a value inside awk block. Here is a sample input file to my script P1 10,9:11/18013013582 ,10:1 ,167:0 ,487:5/E.164 11,9:15/310410532169026 ,10:60 ,167:0 ,487:4/IMSI ...
7
votes
3answers
166 views

Local, timestamped logging of all ssh commands?

How can I keep a local, timestamped record of all remote commands I use in ssh (command-line openssh client started through bash)? Requirements: Essential: 100% client-side without relying on ...
5
votes
1answer
71 views

What are the difference between those four commands (fifo, process substitution, redirection…)

My goal is to create a simple echo server using nc and a single fifo. I'm not looking for the best way to do it, I'm merely trying to understand the semantics of the following commands (when does fork ...
5
votes
5answers
209 views

Serialize shell variable in bash or zsh

Is there any way to serialize a shell variable? Suppose I have a variable $VAR, and I want to be able to save it to a file or whatever, and then read it back later to get the same value back? Is ...
2
votes
1answer
73 views

Why is my tar in a script behaving different than using tar manually

I'm writing a backup script for my email and cloud service. For simplicity, I only posted the mail-backup part here. Basically, I have a Host-Machine with some Virtual Boxes running in it. These ...
4
votes
5answers
112 views

bash script [ x$1 = x ]

I am reading bash script I do not understand what is going there. #!/bin/sh [ x$1 = x ] What is going on the second line and what [ x$1 = x ] mean?
0
votes
2answers
90 views

How can I grep for broken HTML tags?

I want to grep through all my HTML files and see if I have any bad tags there, example <br> , <hr> and so on, that is the I want to see what tags are not closed in the HTML file. for ...
2
votes
1answer
275 views

ctrl c vs. ctrl z with foreground job

Ctrl+Z stops the job whereas Ctrl+C kills the job. Why is that? Wouldn't the other way make more sense? z@z-lap:~$ sleep 100& [1] 4458 z@z-lap:~$ sleep 200& [2] 4459 z@z-lap:~$ jobs [1]- ...
0
votes
3answers
56 views

Why doesn't source work when I call bash -c

I want to run a command that sources a script to take on some env. variables before executing, without sourcing them in my current shell. test.env export test=1 None of these commands echo the ...