Linux – way to make objdump read from STDIN instead of a file

bashlinuxstdin

In my specific case, I want to use it to dump what I echo.
I don't want to involve any file…
Is there a way to make objdump read from STDIN instead?

Best Answer

You can't. There is no way around that, you will have to use the temporary file.

Source file readelf.c has this unconditional check (in binutils 2.22-8 at least) before even attempting to open the file:

if (! S_ISREG (statbuf.st_mode))
    {
      error (_("'%s' is not an ordinary file\n"), file_name);
      return 1;
    }

So if the file is anything but regular file (like symlink, or char device as in case of /dev/stdin, /proc/self/fd/*, etc.) it won't work.

Alternatively, you could modify the source and use modified objdump, but there goes your portability.

Related Solutions

Linux – Writing to stdin of background process

You could try writing to it's /proc pid directory. Say your daemons' pid is 2000, try writing to /proc/2000/fd/0

Linux – How to run a command multiple times, using bash shell

I don't think a command or shell builtin for this exists, as it's a trivial subset of what the Bourne shell for loop is designed for and implementing a command like this yourself is therefore quite simple.

Per JimB's suggestion, use the Bash builtin for generating sequences:

for i in {1..10}; do command; done

For very old versions of bash, you can use the seq command:

for i in `seq 10`; do command; done

This iterates ten times executing command each time - it can be a pipe or a series of commands separated by ; or &&. You can use the $i variable to know which iteration you're in.

If you consider this one-liner a script and so for some unspecified (but perhaps valid) reason undesireable you can implement it as a command, perhaps something like this on your .bashrc (untested):

#function run
run() {
    number=$1
    shift
    for i in `seq $number`; do
      $@
    done
}

Usage:

run 10 command

Example:

run 5 echo 'Hello World!'

Best Answer

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