Bash read from file into variable

Note that it is not necessary to quote the command substitution to preserve newlines. Improve this answer.

Zbyszek 1, 17 17 silver badges 23 23 bronze badges. Alan Gutierrez Alan Gutierrez Ok but it's bash, not sh; it may not fit all cases. Note that using cat as above is not always considered a useless use of cat. For new shell scripters like me, note the cat version uses back ticks, not single quotes! Hopefully this will save someone a half hour it took me to figure it out. Watch out for those spaces. Show 11 more comments. If you want to read the whole file into a variable:!

Otherwise, the shell will perform whitespace tokenization and wildcard expansion on the value. See below. Community Bot 1 1 1 silver badge. Thanks only this one worked for me because I needed newlines.

CiroSantilli : On lines? Are you sure there is no automated way? Show 3 more comments. This will swallow newline from multi-line text files — ucipass. With bash you may use read like this:! Reads stdin into a variable, accounting for trailing newlines.

Avoids needing a subshell or command substitution. Your code block also has an extra space at the end, not sure if that's intentional, but it'd indent every subsequent line with an extra whitespace. You can access 1 line at a time by for loop! The program would read that file, parse each line, and set the values into each variable.

Code: The entire template must be completed. All of the Bourne shell builtin commands are available in Bash, The rules for evaluation and quoting are taken from the POSIX specification for the 'standard' Unix shell.. So far i am up to the following but i'm stuck. Note that it is not necessary to quote the command substitution to preserve newlines. This will produce the result the OP is asking for, simply by rearranging some of the captures in the sed replacement expression, and will work fine without GNU sed: Spaces in line are also interpreted as separated lines.

Drop the following function into your bash script. Bash uses a much easier method for parsing and setting variables called sourcing. Sourcing an external file from an executable shell program is a simple method for including the content of that file into a shell program in its entirety. It has so many different aspects that can be explored for mastering oneself in Bash programming. For example: Code: Drop the following function into your bash script. The Solution. When reading a file line by line, you can also pass more than one variable to the read command, which will split the line into fields based on IFS.

The file contains 3 fields: OS, the company and a random value. You can read more about the IFS variable in my post on bash environment variables. In this topic, we will learn how to read the user input from the terminal and the script. We need to print the contents of a file after reading through it. It allows for word splitting that is tied to the special shell variable IFS. I'm using csh. Spaces in line are also interpreted as separated lines.

Alternative Method for file reading Using passing file name from a command. It is primarily used for catching user input but can be used to implement functions taking input from standard input. When writing a bash script, depends on the automation flow sometimes the script has to read the content from the file line by line. An example. I'm creating bash scripts to copy files search errors etc.

I tried the below script from posts but i am unable to fetch every value in a variable. Brief: This example will help you to read a file in a bash script. It works on Linux and OSX. Introduction to the Problem Open the file "file1. Shell Script to Read File. In the following exmaple we read the file numbers.

To see these special variables in action; take a look at the following variables. I intend to read the file line by line and store each line of data into a variable, so that i can used it later. It's very simple command which is use to send or get data from and to any server. Connect and share knowledge within a single location that is structured and easy to search. Would I use awk or grep? I have found ways to read lines into variables with grep but would I need to read the file for each individual item?

The end result is to use these variables to access a database via the command line. So I need to be able to read, store and use these values in other commands. If you want to use awk then. You could use a loop for your file perhaps, but this is probably the functionality you're looking for. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more.

Read multiple variables from file Ask Question. Asked 4 years, 6 months ago. Active 4 years, 6 months ago. Viewed 3k times. Improve this question.