We have a situation where we need to keep a ZIP archive of some data files available on our Ubuntu Linux server so that our satellite offices can grab the information through slower data lines. Problem is, the underlying files change 2-3 times a day. What's a quick, efficient way to only rebuild the ZIP archive file on our Linux system if a file's changed, but leave it as-is if everything's stayed the same?

I've been trying to figure out whether there's a way that I can automate digging through the "referrals" on my site so I can see what searches people did to end up on one of my Web site pages. I'm running a Linux server and have Apache installed, so I get a huge log file with tons of info. But what I'd love is a simple script that will let me get email once a week with a sorted list of what searches people did to get to me. Doable?

I'm trying to write a shell script that will accept a street address and output the latitude and longitude of that address, for geocache purposes. How can I do that?

As part of my work, I take tons of screen captures on our test Apple iPhone for documentation, but my boss wants me to use SEO friendly file names and it's a huge hassle to rename them one by one. Is there some sort of script I can use on my Mac to fix things?

I've got a bet with my husband and you need to help us settle it. I was reading Jane Austen's "Pride and Prejudice" and he said "I bet you $20 that "pride" shows up more than "prejudice" in that book." I think he's wrong, but have no idea how to figure it out. Can you help?

Hey I want a Perl script that reads a file and sends me the number of occurrences of the alphabets in that file... Could you please help me?

i am in big problem so please help on it. below i write the scripts, i don't know it is correct or not, but i want write the shell script for. In particular machine need to check all process are running or not, and we need result to display in the web page like server name = running, not only single server we have so many servers so, result like in the web page:

server1 = running
server2 = not running
server1 = running

like that so many server we have and one more thing is need show in web page with colors and fonts. please help on it!

I want to compare a line in a file with zero(0) and if its more than zero i want to print the prior two lines, can u please help me in solving out this... please

I want to know if there's some way to automate searching the craigslist site with a shell script or similar so that I can keep an eye on it and know when certain rare auction items show up for sale?

This is regarding script #62 (define a word): Looks like WordNet has changed their online version again and I tried the following replacement for the url=

http://wordnet.princeton.edu/perl/webwn?s=

But the script doesn't return anything but goes back to the prompt. I tried the url with a word in lynx and I got the source. Could you push me in a general direction?

Please, gimme a advice how to correctly use loop "for i in `seq 1 10`" for Mac OS X, echo $SHELL->/bin/bash, because when I write simple strip: for i in `seq 1 10`;do echo $i;done it outputs -bash: seq: command not found.

I'm becoming a big Twitter fan, but as a Linux user, I find it darn frustrating that most of the apps out there are for Mac and Windows users. I mean, I'm used to it, but is there at least some way to get to Twitter from the command line?

My boss had a great suggestion for our local business web site: create a stock index like the S&P 500 that's just comprised of companies in our area. He said we should add it to our site but I honestly have no idea how to do that. Help!

I'm studying Unix, and i need help writing a script. The script requires that it outputs the number of months and years from January 2007 to December 2017 inclusive that have a Friday the thirteenth.

In your book Wicked Cool Shell Scripts, on p. 115, Script #40 Reporting Disk Hogs, on the 8th line the second part of the line reads:

    awk -F: '$2 > 99 {print $1} ')

I am very new to shell scripting, so I am probably just not understanding how this line should be interpreted. In my Linux class, I have been learning that in the /etc/passwed file the 1st field is username, the 2nd field is password (x), and the third field is the UID, so wouldn't the $2 above really be $3 so that the script would be checking to see if the UID field, which is field 3 is greater that 99, not the password field,which is field 2? Please let me know, since this is confusing to me. Thanks for your help.

I've been experimenting with mencoder to convert my AVI movies into a format that I can download onto my cellphone and finally found a site where they explain the various parameters needed for the mencoder program to get it to work. Problem is, they're a pain to type in each time. How do I turn an ugly command line invocation into a nice shell script?

Hi i am trying to comapre numbers for the biggest among double type of numbers. For example: 0.254, 0.255, 0.564, 0.984, 0.556, 0.6566, and 0.5666.

I'm using the following script code:

if [ $max -lt $i ]
if [ "$max -lt "$i" ]

But they all give the error message "integer expression expected". Help!

I have a script that does an ftp from a SCO UNIX server to windows server to get files from the windows server. The script is set in the cron to run every xx minutes. Sometimes the script will hang and leave a process running. This can bog down the UNIX server. I want to be able to do two things. 1. I want to make sure that the script doesn't hang - so it should terminate after xx minutes (the files are very small that it is getting). And 2. I want the script to test to make sure that it is not already running, before starting again. THANKS

I've been looking at your script to count executable binaries in the book Wicked Cool Shell Scripts and I think that there's a problem in the script. Specifically, what happens if I have a directory in my PATH more than once?

I run a fairly busy Web site with a variety of different image directories. The problem is, Apache shows directories in a fairly rudimentary way which makes it quite difficult to find a specific image if I don't remember its name. Is there a better way with some sort of shell scripting?

Just picked up your book Wicked Cool Shell Scripts and already have one quick question: While working on the startup scripts, I would like to place log timers at certain portions of scripts. Is it possible to log point A at he beginning of a section, do the processing, log point B at the end of the section and then log B minus A so I know exactly how long a section took to process?

This might sound like some wild conspiracy theory, but I'm looking at my music collection and it sure seems like most of them have exactly 12 tracks, no more, no less. Is there some marketing reason this would be the case, or am I witness to some great conspiracy? :-)

I need to rename thousands of files in MacOS, buried in subdirectories, changing " " to "_". I've found a ton of scripts using Google that purport to do this, but none of them actually work right. Can you please send me a script that does this? I also tried Automator, but it doesn't recurse into subdirectories.

Filenames may have multiple spaces (eg "Holidays/Christmas/Gifts & Stockings (A - G)/stocking.png"). Directory names may have spaces, too.

I have a file containing lines of data that are amounts padded with leading zeros, similar to the snip below.

  0000000004
  0000000016
  0000000012
  0000000008

Using a shell script, how can I add up a column of numbers contained in lines when BASH interprets the numbers as octal when I do in-line math?

i am having difficulties writing a script to back up files which have need modified during the month specified in the option. The command is:
-b username yyyymm
so if i say 200504. i will have to back up all the files in that specific month to my home directory

I need help with a shell script! I want to prompt someone to enter an IP address the automatically increment it and output the sequence of that address and its following addresses, but I don't know how to do that: when I try to increment a value like "10.10.10.27" it fails because it's not a number.

I'm a bit baffled. I'm trying to compare string variables in a shell script to figure out if one value is lexically less (that is, would appear earlier in the dictionary) than another, but it doesn't seem to work at all? Help!

I need to run a Unix application if a different application is running, from within a shell script. How do I do this?

We have several different shell scripts that we run on a daily basis. Sometimes one of the computer operators will execute the shell script as the wrong user (Root for example). This screws up the permissions and owenership on all of the files that the script just touched!!AAAARRGGGGGGHHH!

I am looking for a way, when the script fires, to see who is running it.

I have a series of boxes (over 1,000), that have the same directory that has been used over time as a dumping ground for various 'stuff', and now I need to have them cleaned up, save one sub-directory. What I need to know, is there a way to create a script that will allow any user to delete everything (hidden, directories, links, etc.) from a particular directory, except one sub-directory.

I am trying to write a shell script for automated ssh. vairable user and passwd have initialized correctly, but when I use the following it still prompting me for the password.

ssh -l $user cisdevapp1
$passwd
uptime
exit

I have also tried the following

ssh -l $user cisdevapp1 < $passwd
uptime
exit
EOF

and no luck. Please help?

Dave, where can I find a bash script that can read data from a file; the information should be separated by tabs or commas for easy pickup, and can only be accesed by a row.

Within a Linux shell script to be used as a cron job, how do I calculate the current date, the current date - n days, and the current date + n days ?

This script is to be used to partition an oracle database, and automatically drop old partitions (n+1) and create a new partition (n+1).

How do you write a bash script for example, a user logins to the server's shell, then I want a bash script that will prompt him a password to verify he is a legit user not an intruder. The answer of the password will be located in a file (for example: /etc/verify). If the user not able to type the correct password 3 times the server will kill that connection and bans his IP address from the server.

I am working on a script where I would like to grab the usernames out of the passwd file and add a emaildomain then ftp it. For example I would like to pull the usernames for all users in /etc/passwd and add @domain.com the ftp it to ftp.domain.com . Can you help?

On Solaris I have cron job which creates some log files and it puts it under a directory, this directory name is created based on system date for example directory name are like 08162005, 08172005 so on..

What I need is I want to do a rotation for these log directories every 14 days since these are directories with system dates, I am having little trouble getting this done,

Is there any way you can solve this for me??

Regarding script #41 (calculating available disk space), out of your book Wicked Cool Shell Scripts, I am unclear how I can have this script calculate the free space on one specific drive, namely /Volumes/Documents HD in my case.

I'd also love to know how I can automatically email the results of this same script, say every 24 hours. If you could kindly point me in the right direction, I'm sure I could figure out the rest!

I am working on a script where I would like to grab the usernames out of the passwd file for a defined range of UIDs. For example I would like to pull the usernames for all users in /etc/passwd that are in the range of 5000-5999. Can you help?

Hi Dave. I'm trying to create a shell script in HP-UX Unix that looks like this:

while read usrname
 do
   lsh $usrname
 done < $file

I have several SCO Unix script that read a parameter from user input or otherwise I put the param within my script, such as ftp scripts and so on. How can I read those parameters from a file instead?

Example: I write an ftp script that will connect to a remote location and bring files, right now I write the same script as many times as I have a remote location, but I'd rather substitute the open xxxx from a file. Also if it is an interactive script and the user need to send to more than one location then I need to be able to collect all the location numbers then read then into my script.

Dave, I heard that your book Wicked Cool Shell Scripts won some sort of award or the other? Do tell, what's the story with that?

I need to rotate logs on an IBM AIX 5.1 Unix box, and tried using your script #55, rotatelogs for this but it didn't work, as -maxdepth is not supported in AIX's find command. So, I commented it out, and it worked, but also rotated everything in the subdirectories as well (no problem...backed up directory first, then restored). I am trying to get it to work using -prune which my search in Google found to be a good fix for the lack of maxdepth, but it's not doing what I want. Help!

I looked at a few of the Bourne shell scripts and they seem to use constructs like $( ... ) and $(( ... )) which are not standard Bourne shell (to my understanding). So I actually have three questions, rather than just one:

1. In what flavor of /bin/sh are those scripts written?
2. Can you suggest any references regarding writing portable (Bourne) shell scripts?
3. I would love to find an equivalent reference for what unix utilities *and options* to use for increasing script portability. Any suggestions?

"I've been reading your book Teach Yourself Unix in 24 Hours and learning a lot, but I'm stuck on a disk usage problem. Suppose there are 5 people (A, B, C, D, E) in our group and they share the same directory called "group." The total capacity of this directory is 100 GB. I'm looking for a program/command/script that can be run to generate the following space usage update:

 
    A    5         5%
    B   10        10%
    C   20        20%
    D   40        40%
    E    5         5%
 total  80        80%
  
   free space     20%

I've started to go through your shell script book Wicked Cool Shell Scripts but there is still something I'm unclear on. I'm showing my ignorance here, but how exactly do you save a shell script so you can use it later?"

I have your Wicked Cool book and love it. I am new at scripting and it is helping a ton. Question. I need a script to use the timestamp feature (ingenious by the way) of Script #83 but "get" the files from a remote server like Script #82. Do you have one modified in such a way?

Every *nix implementation is different. But I'm seeing some some shared behavior between HPUX and Solaris with script #52 Killing Processes by Name. The problem is that the script is trying to kill the "tty" name, instead of the pid.

Wish I understood the following line better so I could make it grab the right columns. :-\

pids=$(ps cu -U $user | awk "/ $1$/ { print \$2 }")

First, thanks for writing Wicked Cool Shell Scripts. I've found them quite useful and I've learned many things from those scripts. I just have a question and I was wondering if you could point me in the right direction.

I'm trying to write a shell script that will pull the top-level directories out of a list of file paths, example:

list of files:
/usr/local/test
/usr/bin/test
/opt/Tivoli/dat
/opt/lib/test
/tmp/files/test
/tmp/local/test

Output after script:
/usr
/opt
/tmp

I've just picked up your book Wicked Cool Shell Scripts, and there are a lot of nifty things in it. I too have accumulated a lot of things generally in small scripts or more frequently in bourne/bash functions. I was particularly tickled to see a lot of very similar code, one such that jumped out at me was your gmk function in one script (I called mine kmg).

Would you be interested in some constructive criticism?

In script #52 Killing Processes by Name, I think that instead of:
  awk "/ $1$/{ print \$2 }"
you might consider using
  awk "$NF=="$1" { print \$2 }"

That way, you're not dependent on whitespace.

"My question concerns backup.sh (script #56 in the book Wicked Cool Shell Scripts). I am a little confused how to set up my directory list file INITIALLY to use for the backup script to work. Do you have to do a -f (full backup) first, then I'm free to incrementally backup as desired? Even then I'm only interested in backing some key directories not my whole home space...."

" Hi, I'm a very beginner at shell scripting and unix/linux. I have your book (Wicked Cool Shell Scripts) and it is really great. So far I've done two or three, Inpath is the one i use most. I'm going make a user for an ftp account so my friends can upload/download songs and other files. I decided to use your adduser script for the job but when i run the script i get an erorr like - /etc/passwd : permission denied. How do i give the script permission to write to /etc/passwd? Sorry if this is an obvious question but i couldn't find an answer. I used chmod 755 and ran it as root. By the way, i really like the site and book cover, i wish all linux/programming manuals had really cool covers."

smallest="$(ls -l "$name" $Zout $gzout $bzout | \
awk '{print $5"="NR}' | sort -n | cut -d= -f2 | head -1)"

I'm finding that some number of people are hosting my Janet Jackson "movie" by simply linking it in from their sites, meaning *I* get to pay for the bandwidth. Is there some way to prevent this?