Programming :: Bash Scripting - Pointed In The Right Direction?
Jul 6, 2011
I've been using Ubuntu for about 6 months now, but haven't had a need to start scripting until just recently. I know programming basics, but that's about it.Anyway, I have a program that I would normally run in this manner (note that I didn't create a permanent alias because I've been moving the program around a lot):alias dx='python /path/to/dxProgram.py' dx A_input.dx B_input.dxSo, you see, program dx takes two input files, and 'A' must come before 'B'. I have a folder full of these types of files that I'd like to loop through with this program. They're named as follows:
Now in my bash script, I want to get the output /home/user instead of $HOME once read. So far, I have managed to get the $HOME variable but I can't get it to echo the variable. All I get is the output $HOME.
I need to find a way to download the attachment from a daily report e-mail to me. The kicker is it will need to be down with a cron tabbed bash script.For example, which linux based CLI client is best suited to be scripted?
I'm trying to put together a script that will quickly run through an archive directory of log files that are named by day of the month 01.gz, 02.gz, 03.gz.... 31.gz. The script uses gunzip -c | grep | wc to count up the total number of hourly occurrences of a filename and outputs the results to stdout.
The only snag I have left is the octal limit when it gets to 08 and 09. I've seen examples using perl and awk, but this script uses a number of nested for loops and if statements that I don't want to have to rewrite in a different syntax. I found that I can use num=10#08 to set that variable to a base 10 instead of a base 8, but then I lose the leading 0 again when it passes the number to the next filename variable.
You are probably using systemd (check it with ps --pid 1) and therefore /etc/init.d isn't considered for autostart. Here can you find some information about systemd and autostart [1]. As far as I know systemd isn't intended to start applications with systemd. I recommend you to use the autostart feature of your window manager or desktop environment or at least the .xinitrc.
looking to write a dependency map tree that creates a tree structure of object names . This tree will be written to a file and read back to create the tree structure of files . how to write this using bash ?
I have a file called list.txt with on word on each line that changes in length. I'd like to make a menu, each line being its own choice. I pieced together most of it the only thing missing is a failsafe for typing a number out of range
I need to write a bash script that will allow me to manage my "virtual network" (in reality just a bunch of directories and files). I need to obtain something like : I have my own command 'connect'. We can use it in two different modes: user and admin. If I type 'connect adashiu virtual_machine_name, computer will ask about password, if password is correct he will change a prompt to :
adashiu_at_virtual_machine_name >
after that user can start to use commands reserved only for user mode. Analogically with admin mode: prompt 'admin >' and administrator can only use bunch of commands reserved for him. changing prompt and separated commands for user and admin ?
I've got a situation. I'm having GNU bash version 3.00.16(1) on Solaris 10. I need to declare an array say arr1 which will be populated by an output of a command.
declare -a arr1 arr1=( $(/some/command) )
Supposing it will eventually (after executing the command) have element values as -
arr1[0]=1234 arr1[1]=5678 arr1[2]=7890
Now, I need to declare another set of arrays, one for each of the element values above - e.g.
declare -a arr1_1234 declare -a arr1_5678 declare -a arr1_7890
And I also need to populate elements of each of above 3 arrays with output of another command in a loop. So, these arrays will hold values something like -
I'm able to declare and populate arr1[*]. My question is how do I declare, populate and print the subsequent arrays and their elements?I am feeling rather thick to get this working.
I have wrote a 1 line command that parses a file, locates the IP Address in the file and then trims the output the way I want it, and then sorts numerically and by uniqueness and then >> appends to output.txt
I can get all the IP's into 1 file "output.txt", but what I am really looking for is some type of way to create a text file, for each IP it finds labeled xxx.xxx.xxx.xxx.txt and also put that ip address into that file..
I am trying to create a custom service to manage a minecraft server what runs in a screen session (this is to allow easy console access as opposed to running it as a nohup background process). I am hitting two main issues with this script so far and wondering if anybody is able to shed some light on it, considering I am far from the greatest BASH scripter on Earth.
The issues are related to start and stop. the first issue with start is there is a command run "screen -dmS minecraft java -Xms1024M -Xmx1024M -jar /minecraft/minecraft.jar nogui" what doesn't appear to work, however when run from console (copy and pasted) this command seems to run perfectly. I am uncertain as to why this is not working within the script. Also if run from a script in /minecraft it also appears to work but in the minecraftd script I have created at /etc/init.d it does not work. I think the issue might be related to the location but am not certain on it, nor how to resolve it.
the second issue with stop is that it works sometimes but at other times it does not, overall it seems to work about 30~50% of the time. When it works it passes a couple of disconnection messages to the screen session and then gives the stop command (the command to gracefully terminate the minecraft server). It seems to work more often when using screen that I attach to the minecraft session while it is running but really not sure if this is an issue with my scripting or an issue with how I am passing things to screen.
The full code in /etc/init.d/minecraftd is below
Code:
#!/bin/bash ## Script Information ## Script Author: Berwick East
I was wondering if there is way to hide passwords in bash scripts. For example: I have to write a script to export a full ldap structure, and I'm using the ldapsearch -y passwordfile, where password file is a plain text file that contains the password. Is there a way to hide the password from that file?
I was thinking to remove the r attribute from the file and before the script is lunched to put the attribute back, but is not a good solution, the same with immutable attribute.
At my wit's end I can't find anything that I understand well enough to use. This is for a Unix class, we are working with shell scripting. File1 has 5 in it and File2 has 100 in it.The teacher wants us to read the values then do the math. This is what I have so far:#!/bin/bashvar1='cat File1'var2='cat File2'var3=`echo "scale=4; $var1 / $var2" | bc`echo The final result is: $var3
Is there a way to process individual characters one-by-one from a text file in Bash, or is that hoping for a little too much from this lovable old clunker?
I have a system setup script for my Slackware installations that pulls all packages and source files from another machine and sets everything up to be identical between machines. The script works as expected but make it entirely unattended. How do I make the bash script deal with automatically selecting "Yes" for, for example "Install x(Yes/No): " when prompted by a make file?
i'm in the process of learing C++. currently i'm creating shell scripts to get things done. i'm just curious how, as a programmer using C++ you would get a similar job done.as an example i have a script that takes the contents of files, pipes it to some sed and awk commands, which is piped to create a new file. that file is then imported into a mysql database.if you were going to do this in C++, would you call the sed/awk programs to modify the file, or can it be done within the program itself? i'm probably jumping the gun here because i've just started learing about pointers so this is above my ability
the problem i have is that when i enter my username, the output (my real name) does not display in the output.txt. instead it displays in putty. so when i run my script in putty it shows the message to enter username and after i enter my username my real name appears below it. i want it to show in the output.txt
in bash scripting...say I want to take the input from a user via a question...I would do this:
Quote:
#!/bin/bash
echo "How large do you want this partition to be in GB (enter only the number)?" read PART_SIZE echo "You want your partition to be $PART_SIZE GB" But I don't want to echo it back to the screen, I want to add it to the content of /etc/fstab. I have been mucking around with sed to find the tmpfs partition in /etc/fstab and add the partition size attribute (this is to use the onboard RAM as a volatile partition)...but am not having any luck...
The portion of /etc/fstab that uses /dev/shm for the tmpfs partition is:
tmpfs /dev/shm tmpfs defaults 0 0
So, if a user says "24" GB to the answer (from above), how do I get it to automatically add that value to the tmpfs partition line in /etc/fstab? So it would look like:
tmpfs /dev/shm tmpfs size=24g,defaults 0 0
I understand that I would also have to come up with a way to put "size=XXg", which I could do with a copied over generic file before this action...then the script would have to find "XX" and replace it with the user's figure...
I'm creating a bash script to do some tasks for me. I would like the script to be run at a set time of everyday. My first question is if it is possible that if one of the commands in the script requires sudo, is there a way to get around it with out making sudo not require a password. Such as, is there a way to include the password in the script? If that is the case, I can always just set the file as read only by sudo. I've been looking for a way to do this, with no success. if I have a command that wants input, how do I give it to the program. For example, if I want to make a zip file that is encrypted, the command would go as:
Code:
zip -r example * -e
now how would I get the script to insert my wanted password.
I'm writing a script to execute bash commands in the PHP CLI. I would like to suppress errors from bash and write my own error message if an error occurs. So far I have this (assuming log.txt doesn't exist!):
Code:
tac log.txt 2>/dev/null
Which works as expected, tac kicks up an error but the error is suppressed, but when I use this:
Code:
tac < log.txt 2>/dev/null
I get:
Code:
bash: log.txt: No such file or directory
The tac error is suppressed but bash still gives me a dirty error.
What options should I use when I'm using the sort command to sort the top 5 CPU processes (ps -eo user,pid,ppid,%cpu,%mem,fname | sort ??? | head -5) showing max to min usage?
im trying to learn javascript. so i choose to start out making a image slideshow banner that auto scrolls on load no special buttons. so since i had no idea were to start i found code that was free to use commercial and non commercial and ill be able to change it. heres that code:
I work with modbus protocol(MODBUS/TCP to MODBUS/RTU gateway server) and write a program for work with mbusd. when working with usb to serial adapter and cable, my program works without any problem. but when working with serial cable does not work (without usb to serial adapter) ; when mbusd is runing and i run minicom program in part initializing modem my program works and when minicom lock the serial port my program stop. when close minicom "with no rest modem" (ctrl+a and press q) modbus program and my program works without any problems.
in builder site (mbus.sourceforge.net) posted : note that currently mbusd can't operate with RS-232/RS-485 converters with direction switching by RTS pin. Use converters with automatic data direction control (i.e. Moxa Transio series).
I'm trying to get the substring of a string in bash. Here is the code: Code: #! /bin/bash LOCAL_HOSTNAME=$(hostname) echo $LOCAL_HOSTNAME INDEX_OF=`expr index "$LOCAL_HOSTNAME" 1` echo $INDEX_OF SERVER_HOSTNAME=${LOCAL_HOSTNAME:0:INDEX_OF} echo $SERVER_HOSTNAME
It's supposed to get the current hostname, assign it to variable LOCAL_HOSTNAME, get the first occurrence of "1" from hostname and assign value to INDEX_OF, the get the substring from variable LOCAL_HOSTNAME (starting at index 0 through INDEX_OF) and asign it to SERVER_HOSTNAME. No matter how much I've tried it keeps throwing Bad substitution error at the substring. I've searched and it says it has to be bash... but it is bash, both the sh script and the running shell. The LOCAL_HOSTNAME and INDEX_OF variables are ok.
Here is the output: I've also tried to get the substring without the INDEX_OF but it gives the same error: SERVER_HOSTNAME=${LOCAL_HOSTNAME:0} Code: host1 5 test.sh: 7: Bad substitution
