Running a command line command with PHP

Question

So my problem is the following: I have an R markdown file on my Ubuntu 18.04.3 server that I want to be knitted via command line (this works fine with Rscript -e "rmarkdown::render('path/to/file.Rmd')"), so I tried to run this from PHP with the exec() command (obviously using escape characters). The output from PHP is the following: Execution haltedArray ( [0] => Error: unexpected input in "rmarkdown::render(\" [1] => Execution halted ) when running the following lines of PHP:

exec("Rscript -e \"rmarkdown::render(\'path/to/file.Rmd\')\" 2>&1", $output);
print_r($output);

What is the unexpected input?

Lawrence Cherone · Accepted Answer · 2020-03-31 23:48:48Z

2

Don't escape the inner ''s

exec("Rscript -e \"rmarkdown::render('path/to/file.Rmd')\" 2>&1", $output);

.. or change the outermost string characters to use single quotes instead of double:

exec('Rscript -e "rmarkdown::render(\'path/to/file.Rmd\')" 2>&1', $output);

.. dont escape both unless you use both, which is ugly and confusing

exec("Rscript -e \"rmarkdown::render(\\\"path/to/file.Rmd\\\")\" 2>&1", $output);

edited Mar 31, 2020 at 23:48

answered Mar 31, 2020 at 23:37

Lawrence Cherone

46.7k7 gold badges66 silver badges107 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

RedBassett Over a year ago

Why is this answer correct? Why wasn't the original version with escaped double quotes inside double quotes working?

Lawrence Cherone Over a year ago

@RedBassett thanks for edit, i rushed to post, was editing but you did it

Lawrence Cherone Over a year ago

np, glad it helped.. ruddy quotes will get ya every time

Collectives™ on Stack Overflow

Running a command line command with PHP

1 Answer 1

3 Comments

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Related