Unix - "xargs" - output "in the middle" (not at the end!)

To answer the original question asked in the title of how to use xargs with the input in the middle rather than the end:

$ echo a b c | xargs -I {} echo before {} afterbefore a b c after

This replaces {} in the command with the piped output. There are some subtle differences between BSD and GNU xargs described below:

BSD xargs (e.g. on MacOS/Darwin, freebsd)

Use -I REPLACE, which will replace the string REPLACE (or whatever you pass) in the command. For example:

$ echo a b c | xargs -I {} echo before {} afterbefore a b c after$ echo a b c | xargs -I REPLACE echo before REPLACE afterbefore a b c after$ echo 'a> b> c' | xargs -L1 -I {} echo before {} afterbefore a afterbefore b afterbefore c after

The man page describes the option:

 -I replstr     Execute utility for each input line, replacing one or more occur-     rences of replstr in up to replacements (or 5 if no -R flag is     specified) arguments to utility with the entire line of input.     The resulting arguments, after replacement is done, will not be     allowed to grow beyond replsize (or 255 if no -S flag is speci-     fied) bytes; this is implemented by concatenating as much of the     argument containing replstr as possible, to the constructed argu-     ments to utility, up to replsize bytes.  The size limit does not     apply to arguments to utility which do not contain replstr, and     furthermore, no replacement will be done on utility itself.     Implies -x.

GNU xargs (e.g. on Linux)

$ echo a b c | xargs -i echo before {} afterbefore a b c after$ echo a b c | xargs -I THING echo before THING afterbefore a b c after

Use either the -I REPLACE or the the -i argument, which the man page describes:

   -I replace-str          Replace occurrences of replace-str in the initial-arguments          with names read from standard input.  Also, unquoted blanks do          not terminate input items; instead the separator is the          newline character.  Implies -x and -L 1.   -i[replace-str], --replace[=replace-str]          This option is a synonym for -Ireplace-str if replace-str is          specified.  If the replace-str argument is missing, the effect          is the same as -I{}.  This option is deprecated; use -I          instead.

The -L 1 on -I means that it will execute each of the input in a separate command:

$ echo "a> b> c" | xargs -I THING echo before THING afterbefore a afterbefore b afterbefore c after

(-i does not have this effect, though is apparently deprecated.)

If your version of xargs doesn't include the -I feature, an alternative is to write a little shell script containing the command you want to execute:

#!/bin/shexec i586-mingw32msvc-g++ "$@" -o outputFile...

Then use xargs to run that:

find . -type f -name "*.cpp" -print | xargs my_gcc_script

You do not need xargs for this. Just use:

g++ `find . -type f -name '*.cpp'` -o outputFile