assign file text to variable within makefile

[alex]

$ tree
├── makefile
├── snippet.txt
└── template.txt

$ cat makefile
test:
sh -c "input=$(cat snippet.txt) envsubst < template.txt > output2.txt"

$ cat snippet.txt
xxx
yyy
zzz

$ cat template.txt
START
$input
END

$ input=$(cat snippet.txt) envsubst < template.txt > output1.txt

$ make
sh -c "input= envsubst < template.txt > output2.txt"

I point out that after "input=" maybe something is missing

Anyway let's check the outputs

$ cat output1.txt
START
xxx
yyy
zzz
END

OK

$ cat output2.txt
START

END

As you can see it's missing
Why?

[Dan Purgert]

Post by alex
$ input=$(cat snippet.txt) envsubst < template.txt > output1.txt

(snip working as expected)

Post by alex
$ make
sh -c "input= envsubst < template.txt > output2.txt"
[...]
$ cat output2.txt
START
END
As you can see it's missing
Why?

Because you have "input= " (i.e. "input is NUL") coming out of the
makefile.

[alex]

Post by Dan Purgert
Because you have "input= " (i.e. "input is NUL") coming out of the
makefile.

and so a possible solution?

[Dan Purgert]

Post by alex

Post by Dan Purgert
Because you have "input= " (i.e. "input is NUL") coming out of the
makefile.

and so a possible solution?

Use makefile variables, rather than shell commands. Or maybe do that
stuff in a script rather than a makefile.

Not 100% sure, really, I don't use make for much other than triggering
compilation or uploading completed work to a microcontroller.

[alex]

Post by Dan Purgert
uploading completed work to a microcontroller.

Meaning what?

[Dan Purgert]

Post by alex

Post by Dan Purgert
uploading completed work to a microcontroller.

Meaning what?

Meaning exactly what I said. It invokes the necessary command(s) to
kick the compiled program(s) to a target device.

[alex]

Post by Dan Purgert

Post by alex

Post by Dan Purgert
uploading completed work to a microcontroller.

Meaning what?

Meaning exactly what I said. It invokes the necessary command(s) to
kick the compiled program(s) to a target device.

Sorry for the absence, i took a Christmas break.

Basically something like this

rsync -ai -delete SRC DEST

?

[alex]

Post by alex

Post by alex

Post by Dan Purgert
uploading completed work to a microcontroller.

Meaning what?

Meaning exactly what I said.  It invokes the necessary command(s) to
kick the compiled program(s) to a target device.

Sorry for the absence, i took a Christmas break.
Basically something like this
rsync -ai -delete SRC DEST
?

is there anyone?

[Dan Purgert]

Post by alex

Post by Dan Purgert

Post by alex

Post by Dan Purgert
uploading completed work to a microcontroller.

Meaning what?

Meaning exactly what I said. It invokes the necessary command(s) to
kick the compiled program(s) to a target device.

Sorry for the absence, i took a Christmas break.
Basically something like this
rsync -ai -delete SRC DEST

No, it launches whatever program is necessary for flashing the
microcontroller or EEPROM, etc. (usually something like minipro or
avrdude, or whatever nonsense the RP2040 needs)

[Lem Novantotto]

Post by alex
sh -c "input=$(cat snippet.txt) envsubst < template.txt > output2.txt"

sh -c 'input=`cat snippet.txt` envsubst < template.txt > output2.txt'

[alex]

Post by Lem Novantotto

Post by alex
sh -c "input=$(cat snippet.txt) envsubst < template.txt > output2.txt"

sh -c 'input=`cat snippet.txt` envsubst < template.txt > output2.txt'

$ cat snippet.txt
"autoload": {
"psr-4": {
"aaa\\bbb\\": "src"
}
},
"require": {
"ccc/ddd": "^1.0",
}

$ sh -c "autoload=`cat snippet.txt`"
sh: 1: autoload:: not found
sh: 2: psr-4:: not found
sh: 3: aaa\bbb\:: not found
sh: 4: Syntax error: "}" unexpected

How many stories for a trivial problem :(

[Lem Novantotto]

Post by alex
$ cat snippet.txt
"autoload": {
"psr-4": {
"aaa\\bbb\\": "src"
}
},
"require": {
"ccc/ddd": "^1.0",
}
$ sh -c "autoload=`cat snippet.txt`"

$ sh -c 'autoload=`cat snippet.txt` && echo "$autoload"'
"autoload": {
"psr-4": {
"aaa\bbb\": "src"
}
},
"require": {
"ccc/ddd": "^1.0",
}

[alex]

...

Sorry for the absence, i took a Christmas break.

In summary, you have to use single quotes.
So, the substitution
(https://en.wikipedia.org/wiki/Command_substitution) is done by the sub
shell, and not by the shell

sh -c "..." # ERROR
sh -c '...' # OK

$ sh -c "echo `cat snippet.txt`"
autoload: {
sh: 2: psr-4:: not found
sh: 3: aaa\bbb\:: not found
sh: 4: Syntax error: "}" unexpected

$ sh -c 'echo "`cat snippet.txt`"'
"autoload": {
"psr-4": {
"aaa\bbb\": "src"
}
},
"require": {
"ccc/ddd": "^1.0",
}