How do I read a file from a while loop?
The following syntax is used for bash shell to read a file using while loop:
- while read -r line; do. echo “$line” ; done < input.file.
- while IFS= read -r line; do. echo $line; done < input.file.
- $ while read line; do. echo $line; done < OS.txt.
- #!/bin/bash. filename=’OS.txt’ n=1.
- #!/bin/bash. filename=$1. while read line; do.
What type of loop was used to iterate through the lines in a file?
Use a for-loop to iterate through the lines of a file Inside the with-statement, use a for-loop to iterate through the lines. Then, call str. strip() to strip the end-line break from each line.
How does the while Read loop in shell work?
Here, catreads each line from standard input and writes the line to standard output. It continues until the end-of-file condition is reached on file1, then it stops. In shell programming, we can read a line from standard input using the readcommand. The readcommand succeeds so long as a line can be read.
How to redirect a file to while loop?
You can also use other commands like head, tail, and pipe it to while loop. We can redirect the content of the file to while loop using the Input redirection operator (<). You can also store the file name to a variable and pass it through a redirection operator.
How to read each line of a file using shell script?
1. Use a for loop The read command in the While loop reads a line from standard input and saves the contents to the variable line. In this case, the -r option guarantees that the content read in is the original content, meaning that the backslash escape will not occur.
How to read from two input files using Bash?
Open the two files on different file descriptors. Redirect the input of the read built-in to the descriptor that the file you want is connected to. In bash/ksh/zsh, you can write read -u 3 instead of read <&3. while IFS= read -r lineA && IFS= read -r lineB <&3; do echo “$lineA”; echo “$lineB” done