====== BASH - Files - Read a file - Read from a command instead of a regular file ======

<code bash>
some_command | while IFS= read -r line; do
  printf '%s\n' "$line"
done
</code>

----

===== With find =====

Process the output of find with a block of commands:

<code bash>
find . -type f -print0 | while IFS= read -r -d '' file; do
    mv "$file" "${file// /_}"
done
</code>

<WRAP info>
**NOTE:**  This reads one filename at a time from the find command and renames the file, replacing spaces with underscores.

  * **-print0**:  uses NUL bytes as filename delimiters.
  * **-d ''**:  Instructs it to read all text into the file variable until it finds a NUL byte.
    * By default, **find** and **read** delimit their input with newlines; however, since filenames can potentially contain newlines themselves, this default behavior will split up those filenames at the newlines and cause the loop body to fail.
    * **IFS= **:  Set to an empty string, because otherwise read would still strip leading and trailing whitespace.
  * **|**:  Pipe the output from the find command into the while loop.
    * This places the loop in a "sub shell", which means any state changes you make (changing variables, cd, opening and closing files, etc.) will be lost when the loop finishes.
    * To avoid that, use a **Process Substitution** - which makes the output of the command_list appear as a filename: <code bash>
    >(command_list)
    <(command_list)
</code>
    * Example: <code bash>
<(ls -al)
</code>


</WRAP>


----

===== Another approach =====

<code bash>
while IFS= read -r line; do
  printf '%s\n' "$line"
done < <(some command)
</code>


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