General :: Reading File Into Variable In Bash?
Mar 21, 2011I know that cat can output the file, but how do you store that output in a variable to process:
Code:
CONTENT=cat file.txt
This doesn't seem to work?
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General :: Why Is Reading A FILE Faster Than Reading A VARIABLE?
May 4, 2011I don't understand the results of a simple performance test I ran using two basic scripts (running on a high end server):
perfVar.zsh :
#!/bin/zsh -f
MYVAR=`cat $1`
for i in {1..10}
[code]...
Performance test result:
> time ./perfVar.zsh BigTextFile > /dev/null
./perfVar.zsh FE > /dev/null 6.86s user 0.32s system 100% cpu 7.177 total
> time ./perfCat.zsh BigTextFile > /dev/null
./perfCat.zsh FE > /dev/null 0.01s user 0.10s system 91% cpu 0.118 total
I would have thought that accessing a VARIABLE was way faster than reading a FILE on the file system... Why this result ?Is there a way to optimize the perfCat.zsh script by reducing the number of accesses to the file system ?
Programming :: Reading A Bash Variable In Bash Scripting ?
Nov 26, 2008I have a config file that contains:
my.config:
Code:
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 $HOME.
Here is my parse_cmd script:
Code:
General :: Bash: Reading File Into Array?
Dec 2, 2010I have a file named file.txt with the following contents
Code:
19 man
24 house
44 dyam
90 random
I want to read the file into array and store each line in each index. I've tried using the following code.
Code:
dataarray=($( < file.txt ))
It stores each word in each index rather than each line in each index.
Programming :: Bash - Read Content Of File To Variable And Use This Variable In For Loop ?
Aug 21, 2009I'm trying to read content of file to variable and use this variable in for loop. The problem is, when I have c++ comment style in file - /*. Spaces in line are also interpreted as separated lines.
For example:
Code:
Changing $files to "$files" eliminate these problems but causes that whole content of variable is treated as one string (one execution of loop).
General :: Bash + Reading Values (numbers) From A File And Storing Them Into An Array?
Nov 4, 2010I have to read a couple of numbers from a random.txt file. In this .txt file there are random numbers. They are separated by a space. Example if you opened test.txt:
test.txt :1 6 1 3 6 8 10 2 4
I would like to read those numbers using CAT and store them into an array:
numlen=${#num[*]} - (must be like this because it is a part of a larger program)
Software :: Get Variable From Text File Into Bash Variable?
Jun 10, 2009I have a text file i that has a mailTo: NAME in it. In a bash script i need to extract NAME and put it in a $variable to use. How do i do this?
View 2 Replies View RelatedGeneral :: Pull String From A File Into A Variable Using Bash
Aug 6, 2011I have a file (.tmpfile) and inside it is a string which i only know part of, the rest being a random group of characters... I would like to know how to pull the whole string out of the file and into a variable.
View 13 Replies View RelatedProgramming :: Zip A Variable With PERL Without Reading Or Writing A File?
Jun 20, 2010There is the Archive::Zip I think I can use with Perl 5.10 but I don't know how. I don't want to read or write any files, just zip something in memory, with best compression, like
$text = "this is a test";
$zippedtext = &Zip($text);
sub Zip {
[code]...
I guess it's only a few lines.
General :: Bash - HISTSIZE - Readonly Variable -bash - HISTFILESIZE - Readonly Variable
Dec 8, 2009On one of my servers I see this when I log in. What does this mean and how can I get it to go away? Everything seems to work fine, but none of my other machines give this error.
View 5 Replies View RelatedProgramming :: Reading From Text File In Bash?
Nov 8, 2010I need to Read a path of a file witch is written in Text file i used this
Code:
FILENAME=$1
while read line
do
echo $line
done < $FILENAME
it worked and showed me the Line witch was written in my file but now my problem is how am gonna use that line as a path i mean for example if am gonna execute a linux command on that file like dpkg -i /path/to/the/file how am gonna export it from The $Line variable and use it after the command.
Programming :: Reading File And Compare In Bash Scripts?
Dec 9, 2010how to program in bash, an i have a problem, i am trying compare values in between 2 values (from another file), so far my solution is to make a nested for loop, but that causes it to compare every value. Here is a visulization of what i want
file.a 2,3,4,5
file.b
3 5
[code]...
i want the values 2, 3, 4, 5 from file.a to be compared inbetween values 3 5, 6 9,1 2, 4 7 from file.b (var1 is the value im comparing, var2 is the less value, var 3 is the greater value)
for i in $var1
do
for k in $var2
do
[code]....
my problem with the above code is it compares EVERYINNG, not the values inbetween what i want (which is 3 5, 6 9 etc).
Programming :: Bash - Reading Csv Delimited File To Array And For Further Manipulation?
Jan 6, 2010I am trying to do this:
1. Read csv delimited file line1 and store all values in array
2. Use the values stored in the array and replace values in other text file with them
3. read line2 in the cvs file and repeat the process
4. Do above for all lines in the cvs file
for example:
file1.cvs content:
text1,text2,text3,"text 4"
a1,a2,3,"a 4"
file.txt content:
some text $array1$ some text
some text $array2$ some text
1. read line 1 - text1,text2,text3,"text 4" put each value in array X[] lines that contain spaces in cvs will have double quotes
2. read x[1] and replace value $array1$ (in file.txt) with x[1]read x[2] and replace value $array2$ (in file.txt) with x[2] and so on
Can above be accomplished in BASH and how?
Programming :: Reading File Permissions Into Bash Array For Processing
Dec 1, 2010I would like to read unix file permissions into a bash array for processing but tbh I have no idea how to do this. Then I will check for each individual access right l, d, x etc.
View 11 Replies View RelatedGeneral :: Bash Script: Use The Directory Of The Script File As Variable?
Jan 16, 2010i'm not actually using Linux but i figured this might be the right place nonetheless..o i've got this little script file to compile and run some Java code:
Code:
#!/bin/bash
cd /Users/acid/Desktop/javaTest
[code]...
Debian :: Sed With Bash Variable In Rules File
Jun 6, 2015How can we do a file replacing string on debian/rules file using sed and bash variable ? I don't seem to be able to do so. I have tried below under the install section with arch dependent amd64, as far as I know all the bash commands are allowed to be executed in debian/rules file.
I have tried this :
Code: Select all
debian/rules file
ipaddr=`<long command to find ipaddr>`
myVar=`hostname`
sed -i -e 's/somestring/'$myVar'/g' $(configs)*
sed -i -e "s/somestring/$myVar/g" $(configs)*
[Code]...
Nothing works. Sed works but the hostname replacement doesn't work.
Ubuntu :: Read A Variable From File (bash Script)?
Nov 8, 2010I googled and tried to find an easy step by step-by-step guide on how to use a bash script read a variable from a file. This is the way I did it (but it does not really work so something is wrong, but what?) (testfil2 contains one line that readsidnumber=1578
#!/bin/bash
value="/home/user1/Desktop/testfil2"
echo $value
kill $pidnumber
Programming :: Bash Scripting...read A Value From A File Then Assign To Variable?
Feb 27, 2011At 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
View 9 Replies View RelatedProgramming :: Parse Multiple Variable From Text File With Bash?
Jul 13, 2010I am trying to think of a logic where my file contains some data I had to read and do some processing. Issue is that file contains data multiple times. For example:
:::::::::::
var1=value1
var2=value2
[code].....
I have to read first paragraph of variables and do some processing and then move on until the end of file. Variable names are same in whole file but for each paragraph the value is different. I can't think of a logic to attain this task. How can I do it? It should be a simple bash script, but I am not able to work out.
General :: Get N-variable Parameters In Bash
Mar 21, 2011I've a script that it's invoked with n-variable parameters. Here's an examples:
Code:
./myprogram.sh inputdir FIELD1 FIELD2 ... FIELDN outputfile In the script I would like to get the FIELD names that were passed.
General :: Substitute Variable In Bash
Mar 21, 2011 Assume that i a having the following three lines in an executable file
#/bin/bash
a=Tue
Tue=1
When i give echo $a the value should be 1, how to do this.
General :: Bash: Input Password Into A Variable?
Aug 22, 2010I'm basically setting up two sshfs mounts and I have it set up so I run one command but type my password twice.Is there an easy to way to input a password using bash and pass that variable to another process asking for a password?
View 5 Replies View RelatedGeneral :: Bash Variable As Parameter To Script?
May 10, 2011I want to create a variable that when passed as a parameter to another bash script will keep its string quotes (so it stays as one parameter). What ways can I achieve this cleanly?
Code:
john@ubuntu:/usr/local/src$ cat foo.sh
#!/bin/bash
echo $0
[code]....
General :: Concatenate Variable Names In Bash?
Apr 7, 2011In my script, and I would like to concatenate 2 variables names, to give me the true variable.I've 3 variables X1, X2 and X3, and I invoked them inside a for loop.
Code:
#!/bin/bash
X1=HELLO
[code]....
General :: Bash Catching The Function Returning Value Into A Variable?
Mar 17, 2010i am dealing with this problemI have a function
function Une {
...
return $some_variable
[code]...
General :: Bash Script - Forget Global Variable's Value?
Apr 9, 2011I have a hard time with my bash script.
It forget global variable's value.
First look at my script.
Code:
Echo "PKGS is [$PKGS] in after loop"
And data file for it is below. Let's name as list.txt
Code:
As you see, PKGS variable in loop has correct value.
However, after loop I can not get proper value for it.
General :: Simple Bash Command Causing Bad Variable Name
Feb 18, 2010When I run this command from shell, it runs ok
export REVS=`svn info svn+ssh://svn.myone.ca/var/svn/story/trunk/lib |grep 'Last Changed Rev:'| awk -F: '{print $2}'`
However when I save it into a file called test.sh (of course, I chmod it with +x), I got error "export: 2: bad variable name"
Here is the file:
#!/bin/bash
export REVS=`svn info svn+ssh://svn.myone.ca/var/svn/story/trunk/lib |grep 'Last Changed Rev:'| awk -F: '{print $2}'`
I am using ubuntu.
General :: Bash Script Variable NULL Instead Of Value Of Expression?
Nov 17, 2010Quote:
#!/bin/sh
for i in {1..10}
do
for j in {1..50}
[code]....
The first echo generates something like: abc.de.fgh The second echo generates:
General :: Environmental Variable In Bash Command String?
Feb 9, 2011I do this:
Code:
a@b:~$ export A=hi
a@b:~$ echo $A
hi
a@b:~$ bash -c "export A=blah; echo $A"
hi
a@b:~$
Why doesn't the bash command print the new value of $A? Is there a way to make it do so?
General :: Bash: Substitute Parameter In A Quoted String - Stored In Another Variable
Jan 31, 2010(variable substitution?)
(parameter expansion?)
Code:
run_repeatedly()
{
NUM=0
while [ <irrelevant stuff here> ]
[Code]....
run_repeatedly "programX -o "./messy/path/output-$NUM.txt"" The echo inside the loop prints "...-$NUM.txt"; obviously I'm aiming to have bash substitute the iteration number so that I end up with many output files not 1.
