Programming :: Bash: Give A Variable The Value Of A Function?
Aug 8, 2010I was wondering if possible in bash for a variable to take the value of a function, I mean the function returns a value and a variable will take it. example:
[Code]....
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Programming :: Does Declaring Variable Inside A Function Give An Extra Overhead On An Application
May 14, 2011Does declaring variable inside a function give an extra overhead on an application? Would it be better to declare the variable globally and just reuse it? Example
Code:
#include <blah>
char mybuffer[2048];
int main()
[code]....
The only difference is the declaration of my variable. Since myfunction() will be called many times will it add an additional overhead if it will create mybuffer[2048] over and over?
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]...
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).
Programming :: C++ Using Private Variable In Public Function?
Feb 6, 2011I have a class in which a have declared a private variable "time". In one of the public functions, I am returning the value of "time" (either directly by using "return time;" or by something similar to "x=time; return x;" but I keep getting a compiling error saying that "time" is not declared in this scope.
View 3 Replies View RelatedProgramming :: Function Pointers With Variable Arguments
Jul 14, 2011I need to call functions that match an input string (if input str = "func1", call func1), so I have this:
Code:
#include <stdio.h>
#include <string.h>
void function_a(void) { printf("Function A
"); }
[Code].....
In the above example, the functions take no input arguments. Can they take a different number of arguments, for example, function_a(int), function_c(int, int), function_e(int, char, int)? How can I do that?
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:
Programming :: Bash Array Add Function Example Using Indirect Array Reference As Function Argument?
Jun 20, 2010I looked on the net for such function or example and didin't find anything, thus after having made one i guess it would be legitimate to drop it to see what others thinks of it.
#!/bin/bash
addelementtoarray()
{
local arrayname=$1
[code]....
Programming :: Bash Function Using If / Then And Else
May 2, 2011I am trying to build a function inside a script.
Code:
#!/bin/sh
#System commands and other configurable.
IPT=/sbin/iptables
IP6T=/sbin/ip6tables
IPST=/usr/sbin/ipset
MODP=/sbin/modprobe
GET=/usr/bin/wget
INT_NET=192.168.1.0/24 .....
I can find lots of tutorials in how to use if, then, else. However, how do I define a variable inside the function?
SEE>>
Code:
for c in $ISO
Also, am I using the 'test' command correctly( -/+ week as valid test)?
Programming :: Sed A Variable In Bash?
Mar 25, 2011I have beat this enough and don't get what should have been a very simple thing to do. I build a variable;
Code:
CLIST=java,lua,python,php,perl,ruby,tcl
CLIST will be used by another bash script but I need to replace the commas with a space. I
[code]...
Programming :: Getting $1 From A Bash Script That Uses A Function?
Jan 23, 2011I made a script that calls a function. However when I run the script I cannot get a value from the first parameter. Here is the function:
Code:
$cat function_library
_file_info()
{
if [ -e "$1" ]
then
[Code]....
Programming :: Variable Substitution In BASH?
Feb 17, 2011Just a simple BASH for loop to read the file path from a text file (clean.txt) echo the variable for debug purposes, and scp it to a server I have using port 50 for SSH.
I've already formatted the entries in clean.txt to handle spaces correctly, using sed replacement.
Example from the clean.txt file:
Code:
/MP3/NAS000000001/Barenaked Ladies/Barenaked Ladies - Barenaked For The Holidays/20 Auld Lang Syne.mp3
/MP3/NAS000000001/Barenaked Ladies/Barenaked Ladies - Barenaked For The Holidays/14 Deck the Stills.mp3
[Code]....
Programming :: How To Use Bash Variable In C Code?
Feb 16, 2011I want to write a c program with some shell scripts.Now For a simple C program. I am Setting a variable called val2 in bash, now I want to use bash variable val2 in C code. How do I do that?The above doesn't work (coz its spawning a different memory space and when shell script ends the variable dies with it as per my research but how do I keep them in same memory space)Also Is there any Good reference where they teach how to integrate C and Bash Together?
View 5 Replies View RelatedProgramming :: (BASH) Keep Variable In Scope?
Jul 15, 2011i've just started to learn about functions in Bash scripting. I'm able to set the functions and execute the commands correctly. However, if my_var is set in the first function and then later in the script in the script the 2nd function is called, it doesn't seem to remember my_var and quits (at least i suspect this is the problem).
Here's my code (it requires yad available via webupd8. org). My specific problem seems to lay in line #27 where if we view the changelog and then exit that window, it returns to the "main" function but any subsequent commands cause a crash. Is this because of the get command on line #29? It's presumably now out of scope after calling menu on line #25?
Programming :: Bash - Passing Variable To Ssh?
May 8, 2010I have a file with around 1000 IP addresses in it and I need to be able to ssh into each one of them, run a single command, and then exit. I already know the ssh command I want to run and it looks like this:
Code:
shpass -p [password] ssh -p 10022 -o StrictHostKeyChecking=no root@[ip variable] 'reboot'
(I know shpass is not good to use and keys are the correct way but I don't have any other options in this scenario.) if these ip addresses were in a .csv file, by themselves with no other information, how would I create a script to do the above command to each ip until the end of the file?
Programming :: Passing A Variable To Bc In Bash ?
Jan 14, 2009I cannot for the life of me get this little (simple) script I wrote to work. Here is the entire script:
Code:
#!/bin/bash
ASPECT=`mediainfo $1 |grep "Display aspect ratio" |cut -d : -f 2`
HEIGHT=`echo "320 / $ASPECT" |bc`
SIZE=`echo 320x$HEIGHT`
[code]......
An input filename ($1) is fed into mediainfo, which by the use of grep and cut spits out a single number which is the aspect ratio. This is then divided by bc into 320, which gives the desired height dimension for the file that I want ffmpeg to create for me. Finally, ffmpeg runs using the calculated dimensions... Basically, it's the passing of the $ASPECT variable to bc that seems to fail. It looks like bc won't read the output from the mediainfo line... It always crashes out with:
Code:
(standard_in) 1: illegal character: ^M I've tried doing something even simpler like this to debug by just trying it to display the calculation on the screen:
Code:
#!/bin/bash
ASPECT=`mediainfo $1 |grep "Display aspect ratio" |cut -d : -f 2`
HEIGHT=`echo "320 / $ASPECT" |bc`
echo $HEIGHT
and it does the same, so it's definitely bc that won't accept the output from mediainfo.
Programming :: Setting Variable In Bash With Sed?
Jun 18, 2011I am killing myself with this, please someone come to the rescue...
Code:
#!/bin/sh
IFILE=$@
[code]...
Programming :: Bash Function Check For Valid IP?
Apr 16, 2010I have been working on this way too long now...this *should* be simple. I must be missing something simple at this point.
Code:
function f_is_ip()
{
if [ "`echo "$1" | /bin/egrep "[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}"`" != "" ] ## Error on this line
[Code]....
When I echo $1 ## prints 192.168.1.22
Programming :: Bash Function For Searching Files ?
Jun 15, 2011I'm making a small script for searching and doing some operations with photos, but I'm kinda stuck on this little function:
Code:
function findallformat {
prefix=""
if [ $1 = -pre ] then
[code]....
That function should find for every file with a certain type; and you can specify a prefix using a "-pre" followed by the prefix that you want to search. The format should be "stackable", so you can use as many types that you want, without repeating the same function on the code.
Example: findallformat -pre IMG_ .JPG .CR2 #That should search files that start with "IMG_" and finishes with .JPG and .CR2. My problem it's that, when I try to use it on the script, it says "bash: syntax error near `token' unexpected `}'"
Programming :: Finesse Weather Function For Bash?
Feb 4, 2011I found a weather function for bash from searching google, and started to finesse it. This is what I have so far, any tips to finesse it even more?
Code:
# Based on code by Crouse at www.bashscripts.org
weather() {
declare -a WEATHERARRAY
WEATHERARRAY=('lynx -dump "[URL]?hl=en&lr=&client=firefox-a&rls=org.mozilla%3Aen-US%3Aofficial&q=weather+${1}&btnG=Search" | grep -A 18 -m 1 "Current:" | sed -e 's/^[ ]*//' | cut -d '|' -f 1-5 ')
echo Weather for the zipcode of $1:$'
' ${WEATHERARRAY[@] } }
Programming :: Bash Concatenating String To Variable ?
Jan 18, 2011I have a program that loops over each word in a sentence. I need to append a constant to the beginning and end of each word. It works up until the last word on the line.
Code:
Output:
Programming :: BASH - If Variable -eq String Not Working ?
Jan 24, 2010Here is the code:
Code:
How ever when I run this script I get the following error
Quote:
I just don't get it, I have racked my brain trying to figure out every combination of how I should write this if statement and I can't get it to work.
Programming :: Bash: Making A Variable Out Of Two Other Variables?
Mar 18, 2010I need to find the value of:
Code:
$Namenumber
My script asks for the name you want to look up and I want it to return the value of $Namenumber
I was thinking:
Code:
number=$"$name"number
but this returns
Code:
$Namenumber
but does not actually resolve what the variable $Namenumber is equal to.
Programming :: Bash - To Prepend Text To Variable
Feb 13, 2010The output of following code is not like it's intended ...
Code:
This is the output:
Code:
Test prepending ...apple is a nice word, hour is a nice word, But of course what I want to do in the first set of commands is to prepend the word "an" to the words "apple" and "hour" in the for-loop.
Programming :: Bash Redirection With Exec: Specify Fd With Variable?
Feb 21, 2010Within a bash script, I'm attempting to redirect file descriptors with exec, e.g. exec 3>&1 1>&2; however, I'd like to do something like exec $FD>&1 1>&2, which doesn't work because bash tries to execute the value of $FD. Various placements of eval fail, as well. Is there a way around this, or am I stuck hard-coding the descriptor?
View 3 Replies View RelatedProgramming :: Grep For Variable In A Bash Script?
Aug 19, 2010I've tried every combination of ' " that I have come across in similar threads on the forum but no luck.. I have 2 files
strings.txt: contains a list of numbers, 4 digits per line file.
txt: contains a lines that I want to grep for the strings.
for example:
>cat strings.txt
3214
8746
2411
[code]....
if I echo $i in the loop, I print out the contents of strings.txt If I put 3214 in place of grep "<$i>" file.txt I get "carls phone number is 3214"
Programming :: Make Bash Replace The Value Of A Variable?
Apr 18, 2009I have a program I am writing where I have a for loop and I want to make it substitute the variable twice like:
for ((i=0;i<5;i++)) do
echo $"$i"
done
[code]...
Programming :: Retain The Eol In Bash Variable Or Ssh Output?
Jan 17, 2011I have to save the result of ssh/grep into a file to keep the eol ("/n"):
ssh $SSH_OPTIONS $USER@$NODE "cd $LOG_DIR; grep -h '$pattern' log.*" > $file
So that when I grep on the local file again later, it can be printed out with original log lines. Otherwise, the log lines will be dropped and lines becomes concatenated into a single line, e.g., if I rewrite the script in this way, echoing the $result is not a good idea..
result=`ssh $SSH_OPTIONS $USER@$NODES "cd $LOG_DIR; grep -h '$pattern' log.*"`
is there some workaround that I can save it to a variable rather than file but still keep the eol? That will simplify my script and don't need to do all those I/Os!
Programming :: Java Output Into Bash Variable?
Feb 20, 2011I have a bash script that calls a java class method. The method returns a string to the linux console when run independently. how can I assign the value from the java method to a variable in a bash script?running the script: java -cp /opt/my_dir/class.method [parameter]
output: my_string if added in a bash script:
read parameter
java -cp /opt/my_dir/class.method [parameter] | read the_output
echo $the_output
the above doesnt work, I also tried unsuccessfully:
the_output=java -cp /opt/my_dir/class.method [parameter]
the_output=`java -cp /opt/my_dir/class.method [parameter]`
java -cp /opt/my_dir/class.method [parameter] 2>&1
How can i get the output stored into the_output variable?
Programming :: Keymapping Variable For Bash Script?
Jul 5, 2010Is there a variable which will tell you which keyboard mapping you are using? I want to write a bash script that will change my keymapping from Dvorak keyboard to US keyboard. I cannot seem to find a variable to read from. I was going to use the "if [ ] then; statement".
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