assign bash result to variable

You can also do way more complex commands, just to round out the examples above. So, say I want to get the number of processes running on the system and store it in the ${NUM_PROCS} variable.. All you have to so is generate the command pipeline and stuff it's output (the process count) into the variable.

A shell assignment is a single word, with no space after the equal sign. So what you wrote assigns an empty value to thefile; furthermore, since the assignment is grouped with a command, it makes thefile an environment variable and the assignment is local to that particular command, i.e. only the call to ls sees the assigned value.. You want to capture the output of a command, so you need to ...

To assign output of any shell command to variable in bash, use the following command substitution syntax: var =$ ( command-name-here) var =$ ( command-name-here arg1) var =$ (/ path / to /command) var =$ (/ path / to /command arg1 arg2) OR use backticks based syntax as follows to assign output of a Linux or Unix command to a variable: var ...

Let's now take a look at the simple example of setup a variable for a command to change the output color: #!/bin/bash. GREEN=$(tput setaf 2) echo "${GREEN}Please". ORANGE=$(tput setaf 9) echo "${ORANGE}Visit" echo "${GREEN}Paris". In the snippet, we've used the tput command and assigned the returned value of those commands to print colorful text.

When you execute a command, you can print the output on the terminal, or you can save the output to a variable in Bash Script. To store the command output in a variable, use the following syntax: var=$(COMMAND) var=$(COMMAND ARGUMENT1) Alternatively, you can use the backtick (`) to do the same task. Basic syntax using backtick is given below.

In Bash scripting, storing the output of a command is a fundamental task. The task includes command substitution and variable assigning techniques. One can substitute commands using dollar signs or backticks. Later, assign the output to a variable. After assigning the variable, one can reference and utilize it throughout the script as needed.

To store the output of a command in a variable, you can use the shell command substitution feature in the forms below: variable_name=$(command) variable_name=$(command [option ...] arg1 arg2 ...) OR. variable_name='command'. variable_name='command [option ...] arg1 arg2 ...'. Below are a few examples of using command substitution.

Here, we'll create five variables. The format is to type the name, the equals sign =, and the value. Note there isn't a space before or after the equals sign. Giving a variable a value is often referred to as assigning a value to the variable. We'll create four string variables and one numeric variable, my_name=Dave.

The first line #!/bin/bash specifies the interpreter to use (/bin/bash) for executing the script.Then, three variables x, y, and z are assigned values 1, 2, and 3, respectively.The echo statements are used to print the values of each variable.Following that, two variables var1 and var2 are assigned values "Hello" and "World", respectively.The semicolon (;) separates the assignment ...

I'm trying to assign the output of a grep command to a variable in a bash script and the variable comes up empty. When I run the following: The output is: If I run the grep command outside of the script (and substitute the variables for real values) I get the output I'm expecting. Here is a snippet of script. Use this script and add the values ...

Once this is done, I want to assign it to the variable comp then I can re-use it later on in the script. Here I am just trying to echo it to the stdout so I can see it worked. If I run the script and enter my name as Ronald McDonald the result I get returned is RonaldMcDonald} with that curly brace on the end of his name, or whatever I type in.

H ow do I assign printf command result to a shell variable under Unix like operating systems? The printf command syntax is as follows: printf "FORMAT" var. var =$ (printf "FORMAT" var1) var = "$(printf "FORMAT" var1)"

This is useful to direct output from a grep command to the shell variable and display on screen at the same time. Dealing with a command that produces large amount of outputs. If you need to save the results of a command that produces a large output, like "du command" or "df", you can store it in a shell variable. However, the output ...

echo "output${nl}${nl}" # 2 in the string + 1 by echo. # append a character to the total output. # and strip it with %% parameter expansion. prints (3 newlines kept): Use an output parameter: avoiding the subshell (and preserving newlines) If what the function tries to achieve is to "return" a string into a variable , with bash v4.3 and up, one ...

I have a bash script that produces a cat output when it takes an argument. I also have another bash script that executes the first bash script with an an argument that I want to produce cat outputs with. How do I store those cat outputs produced by the first bash script in variables?

Each time you use a pipe | the command on the right of the pipe is executed in a subshell, and it takes resources to open a new subshell (it's like opening a new instance of bash to execute that command). If you can avoid it, avoid it. Here, piping an echo to bc will run the command bc in a subshell and is, in some sense, retarded (no offence), since bash has the wonderful here-string ...

Mar 20, 2016 at 10:58. 1. No; if you want to keep some verbosity (but still only record the return value in the variable), you could use: var=$(function $@ >&2; echo $?) instead, which would redirect all output except the return value to stderr. - Geoff Nixon.

I would use a temporary file to store the complex function result, and then read the value from the temp file for processing. # Create a temp file for storage. tmppath=$(mktemp) # run the command and get the output to the temp file. complex_command > "${tmppath}" # read the file into variable. message=$(cat "${tmppath}") # use the variable.