grepc_c(1)                  General Commands Manual                 grepc_c(1)

NAME
       grepc_c - print PCRE patterns for searching C code

SYNOPSIS
       grepc_c [option ...] pattern

DESCRIPTION
       grepc_c(1) is a driver for grepc(1).  It prints PCRE patterns that
       grepc(1) will use to search for declarations, definitions, and/or uses
       of pattern in C source code.

       pattern is a PCRE pattern.  It normally represents a C identifier, and
       word boundaries are implicitly added to it in most cases.

   Types of code
       This program can produce PCRE pattern for several types of code.  The
       following arguments can be passed to the -t option to select the types
       of code that will be searched.

       e      enum constant definitions.

       f      Function prototypes and definitions.  This can be further
              subdivided into:

              fp     Function prototypes.

              fd     Function definitions.

              fl     Linux kernel system calls.  This can be further
                     subdivided into:

                     flp    Linux kernel system call prototypes.

                     fld    Linux kernel system call definitions.

              fg     glibc internal names of libc functions.  This can be
                     further subdivided into:

                     fgp    glibc prototypes.

                     fgd    glibc definitions.

       m      Macro definitions.

              mf     Function-like macro definitions.

              mo     Other macro definitions.

       t      Type definitions.

       u      Uses.  Searches occurences of pattern within enums, function
              bodies, macro replacements, and type definitions, and prints the
              whole enum, function, macro, and/or type definitions.  In this
              case there are no word boundaries set by default, so if pattern
              is open, fopen will also be found; that's to allow searching for
              patterns containing any sequence of characters.

              This can be further subdivided into:

              ue     Uses within enum definitions (except as an enum
                     constant).

              uf     Uses within function definition bodies.

              um     Uses within macro replacements.

              ut     Uses within type definitions (except enum; that is:
                     typedef, struct, or union).

OPTIONS
       -t type
              Restrict the search to a specific type of code (see Types of
              code under DESCRIPTION).  This option can be passed multiple
              times to search for various types of code.  Default: e f m t.

EXAMPLES
       alx@devuan:~$ grepc_c -tm alignof;
       (?s)^[ \t]*#\s*define\s[\s\\]*alignof\(.*?[^\\]$
       (?s)^[ \t]*#\s*define\s[\s\\]*alignof\b(?!\().*?(?<!\\)$
       alx@devuan:~$ cd /usr/lib/gcc/;
       alx@devuan:/usr/lib/gcc$ pcre2grep -rnMf <(grepc_c -tm alignof) .;
       ./x86_64-linux-gnu/15/include/stdalign.h:33:#define alignof _Alignof

SEE ALSO
       grepc(1), pcre2grep(1), pcre2syntax(3), pcre2pattern(3)

Linux man-pages 6.17              2026-01-06                        grepc_c(1)