R 系统函数总是返回错误 127

Question

I need to execute an external tool from R and process errors (if any) occurred in that tool. I know 3 functions to do something familiar with my task:

shell, system and system2.

Trying to test those, I see that command

shell("notepad") 

opens notepad. As far as I know shell doesn't allow to check errors (there's no interface to look into stderr ).

When I call

system("notepad")

or

system2("notepad") 

R freezes trying to make those commands.

Calling

system("start notepad") 

or

system2("start notepad") 

returns warning

Warning message:
running command '"start notepad"' had status 127 

Answer 1

Adapting @DavidTseng's answer (sorry for not having enough reputation to upvote it)...

system("cmd.exe", input = "notepad")

worked for me in Windows.

Answer 2

As I mentioned in my comments, the R documentation reveals that in Windows the system() function does not launch a separate shell (if needed). This is why command line commands run with system() , but Notepad, which needs a separate window, does not run:

From the documentation for system() :

The most important difference is that on a Unix-alike system launches a shell which then runs command. On Windows the command is run directly – use shell for an interface which runs command via a shell (by default the Windows shell cmd.exe, which has many differences from a POSIX shell).

Answer 3

system("bash -l", input = "notepad")

Answer 4

I'm not sure if there's been an update to R that allows this since the question was asked nearly four years ago, but system("\\"C:\\path\\to\\exe.exe\\" args", intern = T) works for me and WILL bring up a separate child window and works on Windows 10 + R 3.6 + RStudio.

Not using the 'intern = T' was giving me a return code of 127 and did not run the process.

Answer 5

I had the same issue. there is an additional step in the installation process which i did not do.

refer to to the url

https://cran.r-project.org/bin/windows/Rtools/

Look for "Putting Rtools on the PATH"

writeLines('PATH="${RTOOLS40_HOME}\\usr\\bin;${PATH}"', con = "~/.Renviron")

Answer 6

对于 Windows 用户错误： system(path("c:", "program files", "r", "anysoft.EXE"))但有效： system(path("c:", shQuote("program files"), "r", "anysoft.EXE"))

Answer 7

You guys are making it so complicated. I solved this problem by referring to this answer . The problem is with the PATH. type Sys.which('') in R, and you will see nothing. So you have to set the path in CMD, and then use Sys.setenv(PATH = '') in R to get this work.