We have env(1) to modify the environment of the command we want to run (for example env MANPAGER=more man dtrace). Is there something similar but for modifying the directory that the command is going to be started in?

Ideally, I would like it to look like this:

theMagicCommand /new/cwd myProgram

This way it could be "chained" with other env(1)-like commands, e.g.,

daemon -p /tmp/pid env VAR=value theMagicCommand /new/cwd myProgram

So far I can think of the following solution, which unfortunately does not have the same interface as env(1):

cd /new/cwd && myProgram

Also, I can just create a simple shell script like this:

#! /bin/sh -

cd "${1:?Missing the new working directory}" || exit 1

shift

exec "${@:?Missing the command to run}"

but I am looking for something that already exists (at least on macOS and FreeBSD).

myProgram is not necessarily a desktop application (in which case I could just use the Path key in a .desktop file).

AFAIK, there is no such dedicated utility in the POSIX tool chest. But it's common to invoke sh to set up an environment (cwd, limits, stdout/in/err, umask...) before running a command as you do in your sh script.

But you don't have to write that script in a file, you can just inline it:

sh -c 'CDPATH= cd -P -- "$1" && shift && exec "$@"' sh /some/dir cmd args

(assuming the directory is not -). Adding CDPATH= (in case there's one in the environment) and -P for it to behave more like a straight chdir().

Alternatively, you could use perl whose chdir() does a straight chdir() out of the box.

perl -e 'chdir(shift@ARGV) or die "chdir: $!"; exec @ARGV or die "exec: $!"

         ' /some/dir cmd args

The toolsets used in the daemontools world, and elsewhere, have this and more besides; have had for many years; and are widely available.

• Wayne Marshall's perp has runtool:

  runtool -c /new/cwd myProgram

  
  


• Laurent Bercot's execline has cd:

  cd /new/cwd myProgram

  
  


• 
  my nosh toolset has chdir:

  chdir /new/cwd myProgram

  
  

All of these are chain-loading tools, designed to be used in exactly these sorts of chains. There is a wide selection of chain-loading tools in these toolkits for other purposes.

Further reading

• https://unix.stackexchange.com/a/353698/5132


• Laurent Bercot (2018-08-01). "Reference". execline. skarnet.org.


• Laurent Bercot (2018-11-08). "Reference". s6. skarnet.org.


• Jonathan de Boyne Pollard (2018). "Command and tool list". nosh Guide. Softwares.

There is such a popular program. It is called ... hold onto your chair... drumroll... env. The GNU version, since version 8.28, not POSIX, has the -C option which lets you set the directory just as you require:

    NAME

           env - run a program in a modified environment



    SYNOPSIS

           env [OPTION]... [-] [NAME=VALUE]... [COMMAND [ARG]...]



    DESCRIPTION

           Set each NAME to VALUE in the environment and run COMMAND.



           Mandatory arguments to long options are mandatory for short options too.



           -i, --ignore-environment

                  start with an empty environment



           -0, --null

                  end each output line with NUL, not newline



           -u, --unset=NAME

                  remove variable from the environment



           -C, --chdir=DIR

                  change working directory to DIR



           --help display this help and exit



           --version

                  output version information and exit



           A mere - implies -i.  If no COMMAND, print the resulting environment.

Certain programs have an option for this, like Git:

-C <path>

Run as if git was started in <path> instead of the current working
directory.

and Make:

-C dir, --directory=dir

Change to directory dir before reading the makefiles or doing anything else.

and Tar:

-C, --directory=DIR

Change to DIR before performing any operations. This option is
order-sensitive, i.e. it affects all options that follow.