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

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4
votes
1answer
633 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 ...
1
vote
2answers
48 views

What's the most efficient way to log crontab shell script errors with error occurred time?

A common way to log crontab task errors looks like below: 1 */8 * * * sh /pseudo_path/test.sh 2>> my_err_log It's a concise command, but it can't record the error occurred time, and the path ...
0
votes
2answers
35 views

Variable expansion inside parenthesis and quotes

In the script below, I can't seem to make $var1 expand in the second statement. I've tried $var1, ${var1}, echo $var1 and '$var1'. It is inside a few sets of quotes and parenthesis which I guess is ...
0
votes
1answer
22 views

Reload network interfaces without rebooting

I'm doing a BASH script for Arch Linux in a Raspberry Pi 2. The thing is that in some point I'd like to reload the network interfaces without reboot and have my new named network interfaces (en0 and ...
1
vote
2answers
31 views

Best way to make variables local in a source'd bash script?

I have a bash script that generates a report on the progress of some long-running jobs on the machine. Basically, this parent script loops through a list of child scripts (calling them all with ...
1
vote
2answers
34 views

How to number a string in each line of a file

Given file.txt that looks like this: line_ some text line_ some text line_ some text How can I number the lines like this with Bash: line_1 some text line_2 some text line_3 some text Here is my ...
1
vote
2answers
11 views

How to pass an argument from a bash script to 'x-terminal-emulator -e bash -c'?

Let's say I've got this script : x-terminal-emulator -e bash -c 'echo hello > ~/text' I call it foo.sh and make it executable. If I execute this script I'll have a text file in my home folder ...
2
votes
2answers
49 views

Bash script function that changes the value of a variable

I'd like to make a function for a BASH script that changes the value of one of its arguments, that is a variable. The function that I did is: chck_rgx () { # Checks that the given name for a ...
4
votes
1answer
60 views

How do I find a file name that's exactly 8 levels deep?

I'm using the 'find' command to search for files in a backup system. I want to find all file names containing a certain string (e.g. 'XYZ') that are exactly 8 levels deep. Is there a find syntax that ...
3
votes
1answer
21 views

Bash script with conf file with unknown number of sets of variables

I am writing a bash script that has a configuration file. The configuration file will have sets of mode and mtu values. There can be zero or as many sets as the user defines. The bash script will ...
0
votes
1answer
40 views

Print the values from files

I have two files $TMP_RPT_FILE and $TMP_RPT_FILE1 . In $TMP_RPT_FILE - Meter readings come and $TMP_RPT_FILE1 - Meter Id come . I want if any data came in any of those files it should print . I tried ...
4
votes
6answers
170 views

Extracting lines based on conditions

Each line in a comma-separated file has 5 fields. a,b,c,d,e f,g,c,i, j,k,c,m,n o,p,c,r,s t,u,c,w, x,y,z,aa,bb How can I extract the lines which have c in the 3rd field and their 5th field is NOT ...
0
votes
0answers
31 views

Drawing a histogram from a bash command output

I have the following output from a miRNA Predictor: Read Sequence:hsa-miR-576-3p MIMAT0004796 (22 nt) Read Sequence:gi|182396|gb|M74088.1|HUMFAPAPC Human APC gene mRNA, complete cds (8972 nt) ...
5
votes
1answer
2k views

Provide two arguments to one option using getopts

In below code when I give option r then getopts requires one arguments: while getopts ":hr::l:" opt; do case $opt in r ) echo "Run Numbers - argument = $OPTARG " ;; l ) echo ...
0
votes
0answers
29 views

How to scan for wireless networks fast

I have written a script which scans for wifi networks with iw dev wlan0 scan and put the SSIDs in a file. Is there a similar tool wich works a bit faster?
2
votes
1answer
40 views

How to create gcov files for a project in a different dir?

I want to analyze code coverage datas. I want to create gcov files from OpenSSL (and from other projects), but I can only create them in the same directory of the project, and only for the files in ...
-3
votes
0answers
44 views

Automate Transferring Files from Windows to Unix through SCRIPT [on hold]

I have to make an AUTOMATED shell script which transfers files from Windows to Unix through FTP. I need to do this file transfer process by running a shell script on putty. Currently I am going ...
0
votes
1answer
10 views

Command Run Differently Depending on How Logged In?

Is there a way to have one command run differently, depending on the manner in which one is logged into the session launching it? Basically, we have a command that when run, launches vim to display ...
0
votes
0answers
25 views

Detect when sdcard removed

I'm working with a small Arm board (Emtrion) running Debian Linux. Emtrion has provided an sdcard image that can update the boards flash. I would like to extend the simple update script, so that when ...
3
votes
6answers
354 views

Grep the text which matches with a pattern

I was looking for a command which will print the selected portion of a line which matches the conditions. Eg, my text line is like this: p1=X||p2=Y||p3=X||p4=X||p5=X||p6=Y||p7=X I want to print ...
1
vote
4answers
102 views

How to use regex in sed?

I need to revoke the sudo access to the user using sed in scripts. I want to comment the user only if the line contains /bin/su - root Let us consider the file as below, in which I have to comment ...
2
votes
2answers
44 views

find closest matching folder

What is the best way to sort the results of $ find . -name scripts -type d by the occurrences of '/' and then choose the first result. I want to create a function that would cd down to a common ...
0
votes
0answers
15 views

Korn Shell script to check if a folder and file exists and print that to a csv file

i am new to unix. I want a Korn Shell script to check if a folder and file exists and print that to a csv file Regards gani
11
votes
2answers
14k views

show the year while listing files in the current directory

I am working on a red hat server I want to list the files in a way where the year when each was file created would appear in the Date how is that possible ?
2
votes
1answer
26 views

Dynamic Variable in KornShell Script

This KornShell Script (ksh): envir=Dev eval "${envir}foo=bar" echo "$Devfoo" Output: bar But I will not know what value is assigned to envir variable. So I want to do something like this where ...
-1
votes
1answer
59 views

Storing command output into a Variable in Bash

#!/bin/bash NEW_TEXT="if failed Send to Karn Kumarl" OLD_FILE="$(awk '{print $1}' RMANJOBS | while read JB;do autorep -j $JB -q;done | egrep "^/|^insert_job|^description" | sed '0~3 a\\')" ...
1
vote
2answers
297 views

Apt-get failing in bash script?

I have several machines (running Ubuntu LTS 12.4 64-bit) which need to be configured in the same way, so I created a shell script which will run automatically the first time the machine boots. It ...
1
vote
1answer
54 views

Convert multilines to single line with SED

I need additional help, based on similar question I have located here: Convert multilines to single line Current SED example (sed -e'y/)},={/(((((/' \ -e's/-\([^(I]*\)[^0-9]*\([0-9]*\)[( ]*/- \2 ...
4
votes
3answers
5k views

How to write a shell script that gets executed on login?

I am trying to write bash shell script in Ubuntu 11.10 Linux distro, that will get executed automatically on logging into the system. But I am not able to figure out that what to write in script that ...
1
vote
3answers
83 views

How to pass variables to awk command with conditions?

I have a while loop which reads data from a file with city names: city_name: COIMBATORE MADURAI PONDICHERRY SALEM TRIPUR TIRUCHI TIRUNELVELI TUTUCORIN VELLORE and using an awk command within the ...
3
votes
3answers
1k views

Bash Script To Find Debian Release Number from /etc/debian_version

The following is what I'm currently using for testing the version of Debian. Instead of doing it this way, can I make it more succinct? #!/bin/bash VERSION=NONE if [ $(cat /etc/debian_version) == ...
1
vote
2answers
247 views

What does [[ -t 1 ]] do?

To my understanding, the script below runs if the user is not root by comparing $EUID and 0. Then, it uses [[ -t 1 ]] to decide if the script is running in a terminal or not. If it is, it will use ...
3
votes
6answers
10k views

Bash script to convert all *flac to *.mp3 with FFmpeg?

I want to convert all *.flac to *.mp3 in the specific folder. This is what I've tried, but not works: # change to the home directory cd ~/music # convert all *.flac files ffmpeg -i *.flac -acodec ...
-2
votes
1answer
38 views

shell script for easing tasks of System Administrators [on hold]

I am planning to develop a Menu Driven script that would enable a system administrator to perform the daily duties with an ease . For eg. 1. Check and Troubleshoot NTP Issues 2. Check and ...
5
votes
1answer
52 views

Variables outside of while loop

I am trying to echo the variables $f1, $f2, etcetera, outside of the while loop shown below. From what I understand, the scope of the variable is not correct. Therefore I tried a few of the ...
2
votes
2answers
588 views

Using chown $USER:$USER inside bash script

In a small bash script I'm running I am attempting to chown a new directory that is created. I've added: sudo chown $USER:$USER /var/www/$sitename sudo chmod 775 /var/www/$sitename after the line ...
-6
votes
3answers
56 views
3
votes
1answer
51 views

How do you use variables with values containing spaces in a Z-shell (zsh) script command?

I have the following Z-shell script: compiler=clang++ standard=-std=c++11 warnings="-Wall -Wextra -Wpedantic" ${compiler} ${warnings} ${standard} -o ${1} ${1}.cpp This does not work as the ...
2
votes
4answers
112 views

Convert multilines to single line

I have multiline log file and I want to convert it to single line log. Multiline example: 6/13/2015 12:00:47 AM - { 562} START Web 6/13/2015 12:00:47 AM - Requested Web connection from ...
0
votes
1answer
638 views

Run a command under sudo over SSH

I am accessing remote machine in Linux using Bash scripting.My code is as follows #!/bin/bash ssh -i manu_bp.pem ubuntu@54.68.67.68 <<EOF sudo -s cat ...
-3
votes
4answers
74 views

Bash error: missing [: missing `]'

I an writing simple script in Bash, to check Linux file system disk usage on root file system and display a warning message if system is greater than 6%. The commands are running in a terminal, ...
26
votes
5answers
10k views

How can I detect if the shell is controlled from SSH?

I want to detect from a shell script (more specifically .zshrc) if it is controlled through SSH. I tried the HOST variable but it's always the name of the computer which is running the shell. Can I ...
14
votes
1answer
448 views

Why won't function return until background process ends?

Consider this script: #!/bin/bash function start { leafpad & echo $! } PID=$(start) echo "PID is $PID" The script does not continue past its closing brace until the leafpad process ends, ...
1
vote
1answer
24 views

Filesize in for loop

I am trying to get the filesize of each file in a folder by using stat in a for loop. I know why the following is going wrong, but I don't have enough knowledge yet on how to fix this. #!/bin/bash ...
2
votes
2answers
111 views

How to check if the parent shell is interactive from a script?

I know that one can use the $- contains i or not or check if $PS1 is empty to tell if a shell is interactive. However, those solutions only work for the current shell. I have a bash script trying to ...
-1
votes
0answers
16 views

how I will make a generic script which will read .sql files and store the data in some temp file [closed]

I have couple of .sql file placed in some different Location of server. I want to make a generic script which will read these files and store the output in some file.dynamically if it can create an ...
-2
votes
0answers
20 views

Shell Script to check the process id

Currently in the box two users are running Ex-sysddsf ,sysddsu using shell script i need to stop process based on the sysddsu ps aux | grep "Dprocess" | awk '{print $12}' Its showing sysddsf ...
0
votes
3answers
81 views

How to rename all files with special characters and spaces in a directory?

How can i rename all the files in a specific directory where the files contains blanks spaces and special characters ($ and @) in their names? I tried the rename command as follows to replace all the ...
0
votes
4answers
90 views

How to extract column name (header) from a CSV file which contains the max value in a row?

I am trying to extract the column name with the maximum value in each row using bash script i.e., the column header value or the value from the same column in the first row. I am using the following ...
1
vote
0answers
28 views

Shell not exiting (possible reason while loop?) [on hold]

In a project, I have two files makefile, script2.sh. I am only allowed to make changes to makefile. The scenario is like this: makefile calls out script2.sh with specific parameters On basis of ...