Change directory in Makefile

TODO: collapasable, copyable, download, etc

In a Makefile, is this good enough to cd into a directory and back out? init-app-data: @echo "Initializing app data..." cd app-ui @$(NPX_BUILD_TOOL) prisma db push cd ..The code snippet you provided for a Makefile target attempts to change directories to app-ui, runs a command with $(NPX_BUILD_TOOL) prisma db push, and then attempts to change back to the original directory. However, this will not work as expected because each line in a Makefile recipe is executed in a separate subshell by default. This means that the cd to app-ui only affects the subshell for that specific line, and the directory change does not persist to the next line.

To correctly handle changing directories within a Makefile recipe, you can group the commands that should be executed in the same directory into a single shell command using && to chain them, or use a subshell. Here are two ways to do this:

1. Using command chaining with &&:

   init-app-data:
       @echo "Initializing app data..."
       cd app-ui && $(NPX_BUILD_TOOL) prisma db push
   

   Here, cd app-ui changes the directory, and $(NPX_BUILD_TOOL) prisma db push is only executed if the directory change was successful.

2. Using a subshell:

   init-app-data:
       @echo "Initializing app data..."
       @(cd app-ui && $(NPX_BUILD_TOOL) prisma db push)
   

   This encapsulates the cd and the command into a single subshell. The directory change and the command execution both happen in the subshell, so they are effectively in the same directory context.

Both methods ensure that the directory change affects the command execution and that you don't need to change back to the original directory, as each command's effects on the directory are scoped to their execution shell.

Change directory in Makefile created at Tue Jan 20 1970 20:23:33 GMT+0000 (Coordinated Universal Time)