Various forms of "cpp -v" to get the output into a file that I can edit have all failed.

I used [Search forums] from the Home page and got zero returns for cpp -v and for "cpp -v".

Assuming there is no rather simple answer to getting that, here is exactly what I hoped to get out of cpp -v which I can see on the console but cannot capture (except by using "script" which introduces additional problems).

Though I am baffled why various forms of "put the output into a file" fail, what got me off on to the "cpp -v" was the desire to know very specifically which c header files went into my compilation.

I am using Debian Linux 4.9.2-10 and gcc 4.9.2 (with some security updates).

Pointers about why my Search Forums failed for "cpp -v" may be illuminating.

Pointer about which forum for this kind of question is more appropriate in will help.

cpp isn't meant to be run standalone, and especially not without a filename, it will wait (forever) for the file data to come in through standard input. From the man page
Note that infile and outfile arguments both are obligated. Another quote
So the input has to look a lot like C

1 members found this post helpful.

Pointers on what did you try exactly may help....
Pointers on what did you search exactly may help...
Pointers on what did you want to achieve at all may help...

I get many returns.

Where?

To redirect output to a file, use the greater sign.
To redirect standard error to a file, use the double greater sign.
To redirect both, use one of these expressions:

No, >> means: redirect stdout and APPEND to the file it redirects TO, so do not overwrite that
To redirect standard error you have to use 2> (redirect the "2" handle) in bash and sh-like shells. That's why 2>&1 works to redirect both: you redirect "2" to where "1" (stdout) is already going. That's why it has to be behind any redirection for 1 (the default is that both 1 and 2 go to the screen).

The standard file descriptors are
0 standard input (stdin), so used for < input redirection
1 standard output (stdout), so 1> is the same as just >
2 standard error (sterr), always needs an explicit 2
and from 3 on are free for the program code to use for files.

See the chapter "REDIRECTION" in the bash man page too.

Brain melt. Lack of sleep? Thanks for correcting me.

1 members found this post helpful.

This is the newbie forum. I tried not to put in so much information that it become TL;DR.

Search LinuxQuestions.org all forums using "cpp -v" or without the quotes. The zero (of less) results were what I thought I reported, but I am new to what I am expected to report.

In my 4th paragraph I thought I made it clear why I was at all interested in "cpp -v".

The L in TLDR means "little" in your case. It's hard to guess what you want.

I understand that you want to write the output of cpp -v in a file. If that is the case:
does the trick.

That infile outfile failed just as many other attempts did to get the output into a file.

What did work was to ignore the outfile requirement and use &>/tmp/a.
It did not occur to me that *all* that verbiage was an stderr response. In retrospect I have only seen short (1 or 2 lines) of stderr which I have generally had no interest in capturing. I suppose the "-v" also threw me off, but I guess one can have "verbose" stderr, too. I was using a suggestion from StackOverflow where it was shown (to someone several years ago) that cpp -v /dev/null /dev/null displayed what I wanted .... on the console screen. No one hinted that what was seen there was all known to be error output.

Though not impressed in my first forum outing here with the majority of replies, yours was the most informational, if not precisely an answer. I'm marking it SOLVED .. with a education to boot. Thanks.

Actually you started with gcc -v which is not cpp -v. So that was a bit misleading for me. Fortunately others understood your post better.....

I did make that error. As a newbie for LinuxQuestions I didn't "sit" on my preview. As you might nod at, I use gcc one heck of a lot more than cpp and have had questions (elsewhere) about gcc switches. I am surprised I caught my rather drastic error as fast as I did ... but not as fast as y'all did.

I would have guessed that most active LQ readers who ever post would let "newbie" questions percolate for a few hours (and let newer LQ members answer the rather easy "newbie" questions) before helping out.

I am impressed how quickly members are willing to help out.