Cobra Interactive Static Code Analyzer

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Version V3.5 of Cobra, with Rule Libraries (June 2021)

Cobra is available on Github at


  • choose a directory where you want to install the tool, below this is referred to as directory $COBRA
       $ git clone
    which gives you a directory with a set of sub-directories like this:
       drwxrwxr-x 2 gh gh 4096 May 16 12:59 bin_linux  # executables for linux
       drwxrwxr-x 2 gh gh 4096 May 16 12:59 bin_cygwin # executables for cygwin
       drwxrwxr-x 2 gh gh 4096 May 16 12:59 bin_mac    # executables for macs
       drwxrwxr-x 2 gh gh 4096 May 16 10:03 doc     # change history, manpage, license
       drwxrwxr-x 2 gh gh 4096 May 16 10:03 gui     # optional small tcl/tk script
       drwxrwxr-x 8 gh gh 4096 May 16 15:55 rules   # cobra checker libraries
       drwxrwxr-x 1 gh gh 4096 May 16 12:43 src     # cobra source files
       drwxrwxr-x 1 gh gh 4096 May 16 12:43 src_app # standalone cobra checkers
  • to compile the tool (if you are not using precompiled executables in one of the ./bin_... directories)
       $ cd src
       # depending on your platform, do:
       	$ sudo make install_linux
       	$ make install_cygwin
       	$ make install_mac
  • add $COBRA/bin_... to your search PATH environment variable, matching the platform you are using. if you use the bash shell, you can add this line at the end of the ~/.bashrc script, where $COBRA is defined as above, for instance:
         export PATH=$PATH:$COBRA/bin_linux
  • configure the tool so that it knows where to find the rule libraries (using the $COBRA directory set at the beginning):
       $ cobra -configure $COBRA/rules
    this creates a ~/.cobra file in your home directory, which cobra reads on startup to find the predefined checker libraries

    you can also tell Cobra where the libraries are by setting and exporting an environment variable C_BASE, for instance as follows:

         export C_BASE=$COBRA/rules
    if both a ~/.cobra file exists and the $C_BASE variable is set, the latter will be used.

Basic Usage

  • cd to the directory with the source files you want to work on, and start cobra. Try a pattern search, for instance for empty if-statements:
       $ cobra -pattern 'if ( .* ) ;' *.[ch]
    Or try some predefined checks:
       $ cobra -terse -f basic *.[ch]
    or for more detail, and with preprocessing enabled:
       $ cobra -cpp -f basic *.[ch]
    add C preprocessor directives on the command-line as needed
  • some of predefined checks:
      $ cobra -terse -f stats     *.[ch]
      $ cobra -terse -f metrics   *.[ch]
      $ cobra -terse -f misra1997 *.[ch]
      $ cobra -terse -f basic     *.[ch]
    for a list:
      $ cobra -lib
    for all command-line options:
      $ cobra --
    or check the online manual pages, which also give details on writing inline cobra programs
  • for interactive use, type for instance:
       $ cobra -cpp *.[ch]
       4 cores, 14 files, 93623 tokens
       :           # << the cobra command prompt
       :           # << type your queries here
       : q         # << quit


  • report problems and bug reports: gholzmann [atsign] acm [dot] org