Home / ubuntu / Questions / 1416722
Accepted
hasanghaforian
Asked: 2022-07-01 23:31:51 +0800 CST

cpp -v command does not end in terminal

  • 772

I use Ubuntu 20.04. When I run cpp -vin terminal the output is like this:

...
...
Thread model: posix
gcc version 9.4.0 (Ubuntu 9.4.0-1ubuntu1~20.04.1) 
COLLECT_GCC_OPTIONS='-E' '-v' '-mtune=generic' '-march=x86-64'
 /usr/lib/gcc/x86_64-linux-gnu/9/cc1 -E -quiet -v -imultiarch x86_64-linux-gnu - -mtune=generic -march=x86-64 -fasynchronous-unwind-tables -fstack-protector-strong -Wformat -Wformat-security -fstack-clash-protection -fcf-protection
ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu"
ignoring nonexistent directory "/usr/lib/gcc/x86_64-linux-gnu/9/include-fixed"
ignoring nonexistent directory "/usr/lib/gcc/x86_64-linux-gnu/9/../../../../x86_64-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/lib/gcc/x86_64-linux-gnu/9/include
 /usr/local/include
 /usr/include/x86_64-linux-gnu
 /usr/include
End of search list.

The problem is after the End of search list, the command does not end until I press CTRL + C.

I want to know what causes this problem and how can I fix it?

20.04

1 Answers

  1. Best Answer

    From man cpp:

       The cpp command expects two file names as arguments, infile and
   outfile.  The preprocessor reads infile together with any other files
   it specifies with #include.  All the output generated by the combined
   input files is written in outfile.

   Either infile or outfile may be -, which as infile means to read from
   standard input and as outfile means to write to standard output.  If
   either file is omitted, it means the same as if - had been specified
   for that file.  You can also use the -o outfile option to specify the
   output file.

    So, since you are not providing an infile, cpp -v is waiting for you to supply standard input via the terminal; if you wish to provide empty input you can use something like

    cpp -v /dev/null

    or

    : | cpp -v
    • 1