cscope: How to use cscope to search for a symbol using command line?

Question

All the cscope tutorials I found online talk about how to use the interactive mode of cscope to search for symbols in editors such as vim and emacs. But I think it should be possible to issue a command in terminal to do something like

cscope -d -some_options <my symbol>

And I should be able to see a list of results in stdout, instead of having to enter the ncurse UI and do everything there. I think this is possible because the "only" frontend cbrowser can do things like that in its TclTK UI. But the code unfortunately is quite beyond me.

However, I found no documentation about this capability.

Am I dreaming or is there an undocumented way of doing this?

Thanks!

UPDATE

Some progress: If I make a small project of a few files with sub-dir structure. Then rici's answer works out of the box. With a bigger project (thousands of files with complex folder structure). Even with a cscope.out and cscope.files present at the root of the project folder (also my current working directory), I got nothing from the same command and same symbol. I suspect that there is a scalability issue with the command. I also tried command

cat cscope.files | xargs cscope -d -L1 <symbol> -i

to no avail.

UPDATE

Extremely bizarre! I tried to use some other symbols. Turned out that the particular symbol I was searching for cannot be shown using the command line. But all other symbols I tried worked. And cbrowser has no problem finding that "failed" symbol. Anyways, I was just in bad luck. I'll ask a separate question about this anomaly in command line.

I marked rici's answer as correct.

Solution 1

You can call cscope with the -R version for recursive searching. For example:

cscope -d -f/path/to/cscope.out -R -L1 some_symbol

(searches for the definition of some_symbol)

cscope -d -f/path/to/cscope.out -R -L3 some_symbol

(shows all locations where some_symbol is called)

You can omit the -f option if cscope.out is located in the current working directory.

Note that the above call yield zero results for an indexed symbol if -R is omitted. Very old cscope versions don't support -R. For example, version 15.8a does support it.

The list of possible values for -L is:

0: Find this C symbol
1: Find this definition
2: Find functions called by this function
3: Find functions calling this function
4: Find this text string
6: Find this egrep pattern
7: Find this file
8: Find files #including this file
9: Find places where this symbol is assigned a value

The -R option can also be used when creating the cscope.out file, e.g.:

cscope -bR

Solution 2

You are probably looking for this:

cscope -L1<symbol>

You could use -d as well, although if you're modifying the files, it's good for cscope to update it's database.

-L means "execute a single line-oriented command", and the following digit (1 in this case), which could also have been written as a separate option, is the specific command, which the manpage confusingly calls a "field". The "fields" are given by the interactive cscope prompt; I added the digit for convenience. "this" refers to the text which follows the digit; remember that it's a pattern so you don't necessarily have to type the full symbol.

 0 Find this C symbol:
 1 Find this function definition:
 2 Find functions called by this function:
 3 Find functions calling this function:
 4 Find this text string:
 5 Change this text string:
 6 Find this egrep pattern:
 7 Find this file:
 8 Find files #including this file: