Trying to create a small script that will read user's input, test if user entered some input and if not display some message or display a text using user's input.
The script is the following but i get an error saying "[: 6: =: argument expected"
I wonder if there is anyway to make a user-defined bash shell function global, meaning the function can be use in any bash shell scripts, interactively or not. This is what I attempted:
Code:
$ tail -n 3 /etc/bashrc
echotm () {
echo "[`date`] $@"
}
[code]....
I want to have a choice or more preferable pass shell as command line argument when I ssh to an linux account.i.e. If John logs in to account "zzz" on server "abc", by default definition of account "zzz" n server "abc" he get csh.But Sally desires that when she logs in to account "zzz" on server "abc", she needs the login shell to be ksh,and Rick wants bash when he logs in to account "zzz" on server "abc".What is the most non-intrusive / easiest way to achieve this? Each user can set their preference on ssh command line or create a simple alias by each shell, but not sure how to do this.
View 6 Replies View RelatedCis 140 student.how to use the test command to evaluate whether the shell variable I create contains a referance to the bash shell? and use the echo command to determine the result.
View 1 Replies View RelatedI need to write a script that will take 1 command line argument. The argument will be a username. The script will determine if the user exists on the system and will print an error if it does not. If the user does exist it will determine if the user is currently logged in, if the user is not logged in it will determine the last time the user logged in and display the file in the users home directory that was most recently modified.
View 2 Replies View Relatedbash 3.1.17(2) I'm trying do write a shell script which must operate on each line of an ASCII text file. So, all the code must be inside a loop, and inside the loop, the first thing should be to read the next line from the file. I have the bash read command. But it reads from stdin. Any way to make read from a file?
View 6 Replies View RelatedI want to do this
read a files's specific line but return as argument only part of it ie
...
value # this is mass
value2 # this is force
so, how can I get / use the $value and $value2 as arguments for some other file and skip the rest of the line(s) ? of course, the values are different everytime, but the comment always the same, as well as the position of the lines in the file
How do i take a single line of input from the user in a shell script?
View 3 Replies View RelatedHere's a challenge I've been struggling for months with:
I have a bash script that reads URL addresses of our internal server and then executes some test commands on them. Something like this:
Code:
read -p "Enter URL: " url
sh execute-what-ever-to $url
After copy-pasting the URL the user taps the enter key and the script proceeds, but here comes the tricky part: I want this to work without the need to press the enter key after copy-pasting the URL.
"read -n" does not work in this case, as the URLs vary greatly in length. However, the URLs always end to the same string. They could be like "http://url1/END", "http://url2/END" and so on. So this ending string "END" could be theoretically used to recognize that the whole URL has been pasted.
If say, I want to read the input given by user at the command prompt and write a code to execute the cmd given then which commands do i use to implement this ( Im writing the code in C )?
View 8 Replies View RelatedDoes anyone know a method of being able to process the complete and literal command line passed to a shell script ? I want to have the command line parameters with ALL characters (including meta characters e.g. $ literally).
So as if there was no shell to substitute or expand parameters nor applying it quoting rules.
Bash 3.1.7
Suppose this bash script:
Code:
#!/bin/bash
ls foo
I would like the output to be
Code:
ls foo
foo
That is, the command is first echoed then executed. Is it possible to do this? Or is the only way to debug the script?
I have a command that outputs n lines of text, and I want to place each line into an array element, but I can't seem to get the syntax correct
So my command is this:
cat $configfile | sed -n '/cluster:'$clustername'/,/cluster/ p' | awk /host/
Which produces many lines depending on the value of $clustername. I'd like to get each line as elements of an array.
I'm writing a Bash script to take IPTC keywords from a text file and write them, via Exiv2, to several (first batch is 100) JPEG files in a single directory. The script has one while loop inside another while loop, both terminated, but I'm pretty sure that's not my problem. I think it's how I'm incrementing the "counter" variable, although it could also be the method of parsing the text lines from the file (using cut with delimiters that have worked fine in simpler scripts).
Here's the code as I've worked it up to this point.
Code:
And yes, "keywords" checks out in Crimson Editor, Emacs GUI and nano as an ASCII file with UNIX line endings. No issues on that score.
Feeding each line consecutively into a terminal (excepting the exiv2 command) works fine: each variable echoes with the part of the text line used as a variable value as it should, even when the b variable is incremented the quick&dirty way (up arrow three commands and hit enter).
Running the above script in eval mode (sh -x) stalls after setting the b variable to one and reading in the first line of text. I'd like to know why. I'd also like some advice on another reliable method of parsing the read-in lines.
basically i have to create a simple program with will continually read input from the user until they enter a blank linei know how to read in certain input but not sure how to get it continually in a loop
View 2 Replies View RelatedI am trying to fix a perl script, and I really suck at perl. But I think this problem will be easy for people who know it.
The problem is, I have an old setup script someone wrote many years ago. It fails if the standard shell is dash and not bash. The only way I've gotten it to work is to point /bin/sh to bash. I looked thru the script and it uses "system" many places, and I think that's the problem.
I searched for it and found this link:url
My plan is to include this function:
Code:
sub system_bash {
my @args = ( "bash", "-c", shift );
system(@args);
}
Then I could simply change all calls to system into system_bash and it should work?
The parameter to the system calls is usually some variable. What if the parameter is a list already? Do I need to test for it somehow, and if it's a list, prepend "bash" and "-c" to the list? How do I do that?
In the script there are lots of places like this:
my $error = system($cmd);
if ($error) {
die/warn "some error message";
}
Shouldn't there be a return in the system_bash function?
I have a output file look like this:
{"test1" : "test2", "test3" : "test4"},
How can I read word by word in each line?This is not working code:
a=0
while read word
do a=$(($a+1));
[code]...
Writing script to create backup of file by adding datetime to file name. Basically test for file presence if there, cp with datetime then rm original cp works fine from command line but get cannot stat `full path to file': No such file or directory
Code:
Here are the errors: cp: cannot stat `~/html/CVP_dadamail/.dada_files/.logs/errors.txt': No such file or directory rm: cannot remove `...': No such file or directory
The for statement is a placeholder as I have same file to backup out of several directories. using "bash -x scriptname" -OR- inserting echos, I can see I've constructed the strings properly. Believing it might be related to the hidden directories, I tried setting the shopt "glob" options to no avail.
Ultimately I'll add the other directories to the for loop and then run this from a cron job, so if you see potential pitfalls knowing I'm headed in that direction...believe construct would be
Code:
I call my script with ./script -e arg2. However, $@ only shows me arg2. Surprisingly, if I use ./script -s arg2, $@ shows me both arguments. What's going on?
View 4 Replies View RelatedFeel free to just link to another thread where this is (pre)solved; I can't search the forum for the word "for," because it's too short (or maybe the search engine dislikes prepositions).
Is there a way to give the 'for' command a range? Here's what I mean:
Code:
#for i in (1-5); do echo $i; done
Certainly, meat space user; I understand exactly what you're thinking.
1
2
3
4
5
True, I realize I could use
Code:
COUNT=1 ; while [ $COUNT -lt 6 ]...
...but if I can avoid the extra preparatory step I'd prefer to do so.
I need user to input a password through command line in Windows cmd prompt. Is there a way to encrypt the input (such as put it into ......) when user is typing ?
View 2 Replies View RelatedI'd like to pass the following arguments to a bash script in any order:
Code:
myscript -l <country> -r <file1> <file2> ... -o
I read the argument list in a switch shift loop. I figured out how to read the filelist but only if -f is the last option.
how to position the file list anywhere in the argument list?
Examples:
Code:
$ ./test.sh -a -c 2
operator is -gt
remcount is
^ value missing!
Code:
$ ./test.sh -b -c 2
operator is -lt
remcount is
^ value missing!
Yet when "-c" is the first argument, its value is present:
Code:
$ ./test.sh -c 2 -b
operator is -lt
remcount is 2
What could I do to ensure the value of "-c" is picked up regardless of the argument order?
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?
View 2 Replies View RelatedI was trying to write a script, but for some reason I can't test two variables using -gt:
a=`expr $currentSize + 0`
b=`expr $fileSize + 0`
[$a -gt $b]
this is what I get:
[22234534: not found
what is the problem? It seems like I can't check if a variable is greater than another but only if a variable is greater than a fixed number. Is that so? By the way the variables $fileSize and $currentSize exist and $a and $b have a value.
Write a program that requires the user to input the name of a file as an argument. If the user fails to include one argument it should make use of a thread that handles a signal. The signal handler should tells the user Incorrect number of arguments and then calls the terminate signal on the process.
If the numbers of arguments are correct then the program should allocate memory space to the file (5MB) and create a child process that requests the user for a character that it should send to the parent. The child should keep request for data until the user keys in the character O. During each request it should pause for 10 seconds, send the character to the parent and then requesting again for another character.
The parent should get the character from the child. Do not make the parent wait for the child to finish requesting for data. Make use of pipes to facilitate communication between the parent and the child. A second child should be created to read and display data from the file. Make use of any appropriate Inter Process Communication technique to ensure that the second child and the parent do not access the file simultaneously (Mutual exclusion).
I need to run a self-test on my external USB drive and don't want to use System -> Disk Utility.I've taken a look at the man page for udisks and curiously, there does not appear to be an option for self tests. Is there a way to run a self test using udisks directly from the command line?
View 9 Replies View RelatedI'm using a remote dedicated server running ubuntu server edition, and I have no idea what the upload/download speeds are.Is there a reliable method to test these speeds via the command line?
View 2 Replies View Relatedsimple bash code:
Code:
#!/bin/bash
trap "echo 'you got me'" SIGINT SIGTERM # to trap ctrl+c
echo "Press ctrl+c during 5 sec loop"
for ((i=0;i<5;i++)); do
[Code]...
How come code behaves normally and stops when ctrl+c signal is caught and resumes, but after I use at least one timeout read in the code it looks like, if signal is caught again it doesn't pause the execution but skips the loop. If you remove -t (timeout) option from the read, both loops look the same!
I have two txt files containing x and y coordinates: xcoord.txt & ycoord.txt. I need to open them; read them line by line to get each coordinate; then each time I need to update Xs and Ys parameters inside another file called "dc.in" with the grabbed values.
Finally each time I need to run two exe files ( dc_2002 and st_vac) and produce corresponding output for each Xs and Ys ( dc.in is an input file for this exe files)
I have written the following code but it does not work: