Linux command output as a parameter of another command
This is what you want:
find . -name myFile -exec cp /home/myuser/myFile {} ';'
A breakdown / explanation of this:
find
: invoking the find command.
: start search from current working directory.- Since no depth flags are specified, this will search recursively for all subfolders
-name myFile
: find files with the explicit namemyFile
-exec
: for the search results, perform additional commands with themcp /home/myuser/myFile {}
: copies/home/myuser/myFile
to overwrite each result returned byfind
to ; think of{}
as where each search result goes.';'
: used to separate different commands to be run afterfind
There are a couple of ways to solve this, depending on whether you need to worry about files with spaces or other special characters in their names.
If none of the filenames have spaces or special characters (they consist only of letters, numbers, dashes, and underscores), then the following is a simple solution that will work. You can use $(command)
to execute a command, and substitute the results into the arguments of another command. The shell will split the result on spaces, tabs, or newlines, and for
assign each value to $f
in turn, and run the command on each value.
for f in $(find . -name myFile)
do
cp something $f
done
If you do have spaces or tabs, you could use find's -exec
option. You pass -exec command args
, putting {}
where you want the filename to be substituted, and ending the arguments with a ;
. You need to quote the {}
and ;
so that the shell doesn't interpret them.
find . -name myFile -exec cp something "{}" \;
Sometimes -exec
is not sufficient. For example, in this question, they wanted to use Bash parameter expansion to compute the filename. In order to do that, you need to pass -exec bash -c 'your command'
, but then you will run into quoting problems with the {}
substitution. To solve this, you can use -print0
from find
to print the results delimited with null characters (which are invalid in filenames), and pipe it to a while read
loop that splits parameters on nulls:
find . -name myFile -print0 | (while read -d $'\0' f; do
cp something "$f"
done)
The pipe will send the output of one program to the input of another. cp
does not read from its input stream at the terminal, it merely uses the arguments on the command line.
You want to either use xargs
with the pipe or find
's exec
argument instead of pipes.
find . -name myFile 2>&1 | xargs -I {} cp /home/myuser/myFile {}
Note: option -I {}
defines {}
as the place holder you could alternatively use someother placeholder if it conflicts with command to be executed.