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Can a command be redirected to a variable in Bash?
You can’t redirect command output to a variable in bash; however you can assign the output of a command to a variable using command substitution Note that counting lines of output from find is not a robust way to evaluate the number of matching files.
How do I redirect output to a variable in shell?
The command outputs the modified content and would commonly be redirected into a file or piped to another command. (E.g. sed, awk, perl, etc.) Putting the read and the mystic_command into a “sub shell” via parenthesis is not necessary but makes it flow like a continuous pipe as if the 2 commands where in a separate script file.
Is it necessary to Parenthesis read and mystic in Bash?
Putting the read and the mystic_command into a “sub shell” via parenthesis is not necessary but makes it flow like a continuous pipe as if the 2 commands where in a separate script file. There is always an alternative, and in this case the alternative is ugly and unreadable compared to my example above. My way is entirely chronological and logical.
What causes a redirection to fail in Bash?
If host is a valid hostname or Internet address, and port is an integer port number or service name, Bash attempts to open the corresponding UDP socket. A failure to open or create a file causes the redirection to fail.
When does a redirection to a regular file fail?
The general format for redirecting output is: If the redirection operator is ‘ > ’, and the noclobber option to the set builtin has been enabled, the redirection will fail if the file whose name results from the expansion of word exists and is a regular file.
How does a redirection work in a shell?
This type of redirection instructs the shell to read input from the current source until a line containing only word (with no trailing blanks) is seen. All of the lines read up to that point are then used as the standard input (or file descriptor n if n is specified) for a command.
How does redirection work in a bash for loop?
You are using > redirection, which wipes out the existing contents of the file and replaces it with the command’s output, inside the loop. So this wipes out the previous contents 10 times, replacing it with one line each time. Without the >, or with >/dev/tty, it goes to your display, where > cannot wipe anything out so you see all ten copies.
How do you redirect a loop in Java?
Or, you can redirect the entire loop once: which runs the entire loop with output redirected, creating (or, with >>, opening for append) only once. You’re only redirecting the echo with “>”, so it overwrites. What you need is to append using “>>” operator.