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

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-1
votes
1answer
113 views

Replace mutiple strings with different values in a file using unix [duplicate]

I have a file in which the data is like below, 01,0000000,xxxxxxx/ 02,xxxxxxxx,yyyyyy/ 03,test1,41203016,,/ 01,0000000,xxxxxxx/ ...
0
votes
2answers
523 views

recording total runtime in bash script

I have the following script. When it runs it prints the Start and end Times to the file 'result.txt'. However, I also want to record the total runtime (end-start), but where I am doing echo runtine ...
0
votes
3answers
8k views

Remove special characters in a text file

I have a text file which contains in each line a sql query. For each line, I need to remove some special characters. Expl: if I have: select * from Users; insert into Users values ('UR01','Kim','...
0
votes
1answer
84 views

How to accumulate data for the previous x number of days

Q: For the argument of the question, say today is 26/03/15. How can I 'accumulate' data for the last 5 days. But these dates are just an example. Ideally I would like to be able to accumulate data ...
4
votes
5answers
376 views

Script tries to create files even though it shouldn't have to?

I have a folder which contains some folders, these folder are moved very often so I made a script to see if they exist, and if not then create them. This is what I did to (which I though would) ...
7
votes
1answer
856 views

Why does `du -sh *` complain about invalid options?

I've searched my best through Google, but for the life of me I can't figure out what to use instead of * (asterisk) after a recent update (even Wikipedia seems to think du -sh * and du -sh * should ...
5
votes
3answers
6k views

KSH - if/then/else vs. double amps (&&) and double pipes (||)

I am wondering what are the best practices regarding if/then/else ; I tend to use the following form (because I find it easier to read) #!/usr/bin/ksh # [[ -f /path/to/target/file ]] && { ...
1
vote
1answer
253 views

read input from user in while loop having input and output redirection

This is my code: while IFS=',' read a b c; do read input echo $input done 3<&0 < input.csv > output.txt I took care of input redirection by redirecting through pipeline. But ...
0
votes
2answers
390 views

How can I filter ping results by time?

How do I filter out any pings that are under a certain ms, ie, only echo ping responses above 500ms to the text file? IP=$1 SECONDS_Between_Pings=$2 ping -i $2 $1 | while read pong; do echo $(date) $...
1
vote
3answers
338 views

UNIX KSH/BASH Call by Reference using Array (at GNU bash 4.2)

I am new to Unix shell scripting My code is as follows: i=0 for var in 'a' 'b' 'c' 'd' 'e' do content[i]=var ((i=`expr i+1`)) done a=10 b=50 c=40 d=90 e=100 Now I wanted to print the local ...
1
vote
2answers
142 views

Redirecting stdout and stderr of specific lines

I am reading a file and redirecting the entire output to a file. I would like to redirect stdout and stderr of certain expressions to screen as shown below (just an example): #!/bin/bash OLDIFS=$IFS ...
4
votes
4answers
208 views

Traverse, copy & transform file names

My issue: I need to copy log files, all with identical names, but stored 1-deep in subdirectories, and change their names. I'm copying from the a folder called Logfiles which contains a bunch of ...
0
votes
0answers
105 views

shell calling another shell program fails when run by crontab

I have scheduled to run the run.sh program like this: 16 09 07 * * root /opt/db_maintain/run.sh > /opt/db_maintain/temp-log and here is the run.sh: #/bin/bash #********* Saman ********* TM=$(...
2
votes
1answer
121 views

About executing shell script

Suppose I have a shell script file foo.sh. I can do chmod + x foo.sh and change it into an executable file. In Kernighan-Pike: Unix Programming Environment (UP) they show that after this typing ...
-1
votes
1answer
112 views

Generate a tarball or (.tar.gz) of the recently modified files in the directory

As the title says, I need help creating a linux script that generates a tarball or (.tar.gz) of all the files in the directory passed in as an argument to the script and have been modified in the past ...
4
votes
3answers
4k views

Tool to generate TCP traffic

I want to generate a TCP traffic starting from the port 0 to the port 65535. 1 tcp packet for each port with 1ms between 2 packets. The generator should not care if there is a TCP ACK or not. Are ...
1
vote
1answer
364 views

KSH/bash for File Creation Dynamically

I am new to ksh and unix and I am learning it: I wanted the following:I have a directory name tmp on that directory on basis of FileName Category I wanted to create 'n' number of files dynamically. ...
3
votes
4answers
532 views

How do I extract the first integer from text string in a column of a tab-delimited file?

I work in Medical Genetics and often have delimited text files where in one column (ex. column 5) there is a text string with a "mutation" in our jargon: c.2458C>T or c.45_46delAA or c....
1
vote
3answers
1k views

Check whether text contains non-ASCII characters in a shell script

I have a file, I want to determine if it contains only English ASCII characters. I thought this is a very common question, but when I googled it, there is no direct answer or related. According to ...
1
vote
1answer
82 views

How to change bash script output when the script is running?

I have the following loop which counts from 0 till 99: #!/bin/bash for ((i=0;i<100;i++)); do echo $i sleep 1 done Is there a way to change the result of the output from terminal while ...
18
votes
2answers
2k views

How did this '&' at the end of my command, make the script SO fast?

While solving some CTF challenges online, I came across a situation where I needed to bruteforce a server. This is the code I wrote: #!/bin/bash for i in {0..9}{0..9}{0..9}{0..9} do echo "...
3
votes
1answer
153 views

automate the process of fixing all broken links

There are lots of broken links in my system. I wrote a script to relink all broken links. But, after the scripts runs, find would again show me that the links still exists. This is my code: find /...
2
votes
2answers
3k views

how to check if both parameters are set in bash? [closed]

Say I have a executable bash file script.sh. I want to use it as ./script.sh p1 p2 p1 and p2 are two necessary parameters for this command. If either one of them is missing, the command should ...
2
votes
1answer
228 views

Using find and sed to copy 20th line of many files into one file

I have a folder called PKA1 Within this folder I have several folders named as: 1eV, 2eV .... 30eV Within each of these subfolders I have a file called PKA.dump I want to copy the 20th line of PKA....
0
votes
2answers
170 views

Recursively remove files with idx > 10,000

The problem In the current working directory I have several (very many) folders and some of them have lots (like 100,000+) of files inside. My goal is getting just the folder with 10,000+ files and ...
1
vote
2answers
2k views

Debian: umount /media/usb0: “Operation not permitted”

I recently moved from Ubuntu 14.10 to Debian Testing. Under Ubuntu I had a shell script for backing up my home folder to a USB stick. The last line of the script unmounts the USB stick. Adapting it to ...
4
votes
2answers
365 views

Increment a variable using a Bash script

I have a file that contains the following text. // // test_file.h // test project // // Created by Test User // #ifndef test_file_constants_h #define test_file_constants_h // Generic includes #...
2
votes
4answers
230 views

How can I find the program I'm hiding in bash

Say I have PATH="home/bob/bin:/usr/bin". I am writing a bash script /home/bob/bin/foo that will do some munging and then call /usr/bin/foo. Of course I want to be able to use this script on ...
1
vote
2answers
171 views

sed - doesn't append new line EOF and replaces letter not defined

I am experiencing a strange behavior using a sed command (got to be sed, no awk in this case) and got two questions for you, hoping someone got the skills to explain me what I am doing wrong. I want ...
1
vote
2answers
160 views

Splitting the working directory in a bash script

If a do: IFS="/" read -ra PARTS And type in a path manually, it creates the array "PARTS" as hoped, however: IFS="/" read -ra PARTS <<< $(pwd) creates an array with a single element, ...
3
votes
3answers
4k views

Variable not expanding inside another variable bash

I am reading a csv file in bash script as follows: resource='/data/bscs/' while IFS='|'read seqid fname fpath do echo "FILENO: $seqid" echo "FILENAME: $fname" echo "...
1
vote
1answer
553 views

Unix Shell : Array assignment not working [duplicate]

I am new to unix shell I am learning array by following code source_array_list[0]="a" source_array_list[1]="a" source_array_list[2]="a" source_array_list[3]="a" source_array_list[4]="a" ...
1
vote
1answer
453 views

Unable to track error

I am new to Unix shell scripting, While running my program I found the following errors today.ksh[36]: test: 0403-004 Specify a parameter with this command. sed: 0602-419 Cannot find or open file /...
0
votes
1answer
90 views

Error while passing variables for keyword match using sed

I am a beginner in scripting. I am writing a bash script for text processing where this command is giving me error: sed -e "/\<$7\>/ /\<$5\>/$6/" < "$2/$1" > "file.tmp" This is ...
1
vote
2answers
176 views

Script to do periodic printing

I have a networked inkjet printer (HP all-in-one photosmart 5510), and currently I have a simple script that reminds me periodically to send a small job for printer so that the ink doesn't dry up. I'm ...
4
votes
3answers
496 views

Bash : Native way to get rid of quotation around each array member

I read an array from another script. This array needs to put " " around all array members since some members are empty. in_file=./data vector=($(./readdata.sh 0 $in_file)) for index in ${!vector[@]} ...
2
votes
3answers
2k views

how to execute commands on remote server as different user

I am trying to connect to server B from server A using ssh and executing commands using some other user. However, when I try searching for a pattern in log file it says "cannot open log file" below is ...
1
vote
2answers
166 views

Bash script strange behavior with echo - printf in a file

I want to print part of the content of a .csv file in another file if there is a match with some condition: The csv content is like this abc test;ABCtest.it xyz test;XYZtest.com I read the content ...
1
vote
1answer
239 views

How can I skip empty files with sed?

I am using sed like this: sed -e 's/ *| */|/g' ${array_export_files[$loopcount]}>>$TEMPDIR/"export_file"_${testid}_${loopcount}_$$ under a while loop but problems come when the file is ...
0
votes
2answers
337 views

Expect Scripts - Reading from Files and Accepting User Input

How can I write an "Expect" script to: iterate over a list of IP addresses and log in to each to perform commands (like in a BASH for loop). Right now I just copy/pasted the few lines that are my ...
1
vote
1answer
111 views

Match closest equal or preceding timestamp

I have a series of timestamps representing events, e.g.: 20150401_1120 // event a 20150401_1211 // event b And a series of logfiles, each representing a fixed period of time and timestamped ...
0
votes
2answers
31 views

Dividing up columns and submitting the value as stdin into a seperate program within a script [closed]

I currently have two programs written in C named "remove" and "calculate". When I call ./remove it removes some data from stdin. When I call ./calculate which takes in an argument and also data from ...
2
votes
2answers
109 views

Is it possible to change the PS1 periodically by a script in the background?

I just came across the PS1 variable (so I am far from being an expert). It is possible to change the prompt by simply changing this variables value, for instance: PS1="\h" hostname as Prompt PS1="\j" ...
0
votes
1answer
86 views

Want material to teach Unix basics [closed]

HP-UX ** B.11.31 U ia64 ** unlimited-user license Hi, I have been working as a script (korn and bash)developer on Unix platforms for 3+ years. I have to train a team on Unix. And although I know a few ...
2
votes
1answer
819 views

cat to stderr while reading to end of file marker

Leaving aside the question of whether usage output should go to stderr or not, if you had to redirect the output of the cat command below to stderr, how would you do it? function usage { cat <&...
0
votes
1answer
52 views

How to set path in cronscript

I am running a cronscript like: */45 * * * * /path/to/php /path/to/file.php it creates a file and put on home directory; But I want to create this file in my desired path like: */45 * * * * /path/...
3
votes
2answers
354 views

Script to hang up Asterisk channels

I am trying to create a script for Asterisk. We use a lot of channspy. Sometimes the channspy stays opened and didn't hangup even if the softphone is hangup (I don't understand why). So I thought of ...
0
votes
1answer
238 views

Modify part of line if keyword is found using sed? [duplicate]

I want to modify a line if a specific keyword is found in a line. CS_CODE, SM_NUM, PORT_NUM, DEV_PORT_NUM, DIRNUM, MAIN_DIRNUM, BILL_NO, ADR_NAME In above line, if 'PORT_NUM' is present then '...
0
votes
1answer
77 views

List files with memory space older than 14 days

In shell scripting how to find 14 days older than files and directory in a account I need to list them with their memory space ex: 0 ./.vxz.tmp 658 ./.zshrc 6 ./dummy.txt 2.1K ./ss1s: 489K ./sss....
0
votes
1answer
428 views

Moving multiple files from one folder to another and rename them [closed]

I have a list of current file names and Original file names in a text file. The current name and the original name are seperated by a Tab or hypen. I want to move the file with the current file name ...