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How to read line by line in Bash?
Maybe IFS is the key point as others said. You need to add only IFS= between while and read. and do not forget quotations of $data, else echo will trim the spaces. But as Joshua Davies mentioned, you would prefer to use the predefined variable $REPLY.
Why does Bash print arguments on separate lines?
Use “$@” to access them one by one. Although echo “$@” prints the arguments with spaces in between, that’s due to echo: it prints its arguments with spaces as separators. somecommand “$@” passes the file names as separate arguments to the command. If you want to print the arguments on separate lines, you can use
How to echo a string with multiple spaces in shell?
The default value of $IFS contains the TAB character, so in echo -e $MYCUSTOMTAB”blah blah”, $MYCUSTOMTAB is just split into nothing so it becomes the same as if you had written: (you probably don’t want -e here btw). Or if you want printf to do the same kind of , expansions that echo -e does, use %b instead of %s:
Is there a way to skip blank lines in Bash?
This version is very fast compared to solutions that invoke external commands like sed and grep. Also it skips lines that contain only spaces, the lines don’t need to be empty to be skipped. Thanks for contributing an answer to Stack Overflow! Please be sure to answer the question.
ProcessText1 needs to call ProcessLine at two places, which might be uncomfortable if you would like to place a block of code there which directly processes the line, instead of calling a function which processes the line; you would have to repeat the code which is error-prone.
How to read a file line by line?
If the above is saved to a script with filename readfile, it can be run as follows: If the file isn’t a standard POSIX text file (= not terminated by a newline character), the loop can be modified to handle trailing partial lines:
What’s the default input descriptor for Bash read?
Based on the accepted answer and on the bash-hackers redirection tutorial. Here, we open the file descriptor 3 for the file passed as the script argument and tell read to use this descriptor as input ( -u 3 ). Thus, we leave the default input descriptor (0) attached to a terminal or another input source, able to read user input.
How to Pip into a while Read loop in Bash?
piping into a while read loop in bash means the while loop is in a subshell, so variables aren’t global. while read;do ;done <<< “$var” makes the loop body not a subshell.