$ /usr/local/apr/bin/apr-1-config --version
1.7.6
$ /usr/local/apr/bin/apu-1-config --version
1.6.5

$ /usr/local/apr/bin/apr-1-config --prefix=/opt/myapr --includedir --link-ld
/usr/local/apr/include/apr-1
 -L/usr/local/apr/lib -lapr-1

$ /usr/local/apr/bin/apr-1-config --help
Usage: apr-1-config [OPTION]

Known values for OPTION are:
  --prefix[=DIR]    change prefix to DIR
  --bindir          print location where binaries are installed
  --includedir      print location where headers are installed
  --cc              print C compiler name
  --cpp             print C preprocessor name and any required options
  --cflags          print C compiler flags
  --cppflags        print C preprocessor flags
  --includes        print include information
  --ldflags         print linker flags
  --libs            print additional libraries to link against
  --srcdir          print APR source directory
  --installbuilddir print APR build helper directory
  --link-ld         print link switch(es) for linking to APR
  --link-libtool    print the libtool inputs for linking to APR
  --shlib-path-var  print the name of the shared library path env var
  --apr-la-file     print the path to the .la file, if available
  --apr-so-ext      print the extensions of shared objects on this platform
  --apr-lib-target  print the libtool target information
  --apr-libtool     print the path to APR's libtool
  --version         print the APR's version as a dotted triple
  --help            print this help

When linking with libtool, an application should do something like:
  APR_LIBS="`apr-1-config --link-libtool --libs`"
or when linking directly:
  APR_LIBS="`apr-1-config --link-ld --libs`"

An application should use the results of --cflags, --cppflags, --includes,
and --ldflags in their build process.

$ A=/usr/local/apr/bin/apr-1-config
$ $A --bindir
/usr/local/apr/bin
$ $A --includedir
/usr/local/apr/include/apr-1
$ $A --cc
gcc
$ $A --cpp
gcc -E
$ $A --cflags
 -g -O2
$ $A --cppflags
 -DLINUX -D_REENTRANT -D_GNU_SOURCE
$ $A --includes
 -I/usr/local/apr/include/apr-1
$ $A --ldflags
（空输出）
$ $A --libs
 -luuid -lcrypt  -lpthread
$ $A --srcdir
/root/src/apr-1.7.6
$ $A --installbuilddir
/usr/local/apr/build-1
$ $A --link-ld
 -L/usr/local/apr/lib -lapr-1
$ $A --link-libtool
 /usr/local/apr/lib/libapr-1.la
$ $A --shlib-path-var
LD_LIBRARY_PATH
$ $A --apr-la-file
 /usr/local/apr/lib/libapr-1.la
$ $A --apr-so-ext
lo
$ $A --apr-lib-target
-rpath $(libdir) $(OBJECTS)
$ $A --apr-libtool
/usr/local/apr/build-1/libtool
$ $A --version
1.7.6
$ $A --prefix
/usr/local/apr

$ /usr/local/apr/bin/apu-1-config --help
Usage: apu-1-config [OPTION]

Known values for OPTION are:
  --prefix[=DIR]    change prefix to DIR
  --bindir          print location where binaries are installed
  --includes        print include information
  --includedir      print location where headers are installed
  --ldflags         print linker flags
  --libs            print library information
  --avoid-ldap      do not include ldap library information with --libs
  --ldap-libs       print library information to link with ldap
  --avoid-dbm       do not include DBM library information with --libs
  --dbm-libs        print additional library information to link with DBM
  --srcdir          print APR-util source directory
  --link-ld         print link switch(es) for linking to APR-util
  --link-libtool    print the libtool inputs for linking to APR-util
  --apu-la-file     print the path to the .la file, if available
  --old-expat       indicate if APR-util was built against an old expat
  --db-version      print the DB version
  --version         print APR-util's version as a dotted triple
  --help            print this help

When linking with libtool, an application should do something like:
  APU_LIBS="`apu-1-config --link-libtool --libs`"
or when linking directly:
  APU_LIBS="`apu-1-config --link-ld --libs`"

An application should use the results of --includes, and --ldflags in
their build process.

$ A=/usr/local/apr/bin/apu-1-config
$ $A --bindir
/usr/local/apr/bin
$ $A --includedir
/usr/local/apr/include/apr-1
$ $A --includes
 -I/usr/local/apr/include/apr-1 -I/usr/include
$ $A --ldflags
 -L/usr/lib -L/usr/lib64
$ $A --libs
     -lexpat
$ $A --srcdir
/root/src/apr-util-1.6.5
$ $A --link-ld
 -L/usr/local/apr/lib -laprutil-1
$ $A --link-libtool
 /usr/local/apr/lib/libaprutil-1.la
$ $A --apu-la-file
 /usr/local/apr/lib/libaprutil-1.la
$ $A --old-expat
@APR_XML_EXPAT_OLD@
$ $A --db-version
0
$ $A --version
1.6.5
$ $A --prefix
/usr/local/apr
$ $A --ldap-libs
（空输出）
$ $A --dbm-libs
（空输出）

$ ./configure --prefix=/usr/local/apr --with-apr=/usr/local/apr/bin/apr-1-config --with-ldap
checking for ldap support...
checking for ldap_init in -lldap50... no
checking for ldap_init in -lldapssl41... no
checking for ldap_init in -lldapssl40... no
checking for ldap_init in -lldapssl30... no
checking for ldap_init in -lldapssl20... no
checking for ldap_init in -lldapsdk... no
checking for ldap_init in -lldap... no
（configure 退出码 0）

checking for ldap_init in -lldap... yes
checking for ldap_start_tls_s in -lldap... yes
  setting LDADD_ldap to "-lldap -llber"
  setting LDADD_dbm_db to "-ldb-5.3"
  setting LDADD_dbd_mysql to "-L/usr/lib/x86_64  -lmariadb -L/usr/lib/x86_64-linux-gnu/ -lmariadb"
  setting LDADD_dbd_sqlite3 to " -lsqlite3"

# 通道一：apr-1-config（经典）
$ gcc app.c $(apr-1-config --cflags --cppflags --includes) $(apr-1-config --link-ld --libs)

# 通道二：pkg-config（现代构建系统 / CMake）
$ PKG_CONFIG_PATH=/usr/local/apr/lib/pkgconfig pkg-config --cflags --libs apr-1
-DLINUX -D_REENTRANT -D_GNU_SOURCE -g -O2 -I/usr/local/apr/include/apr-1 -L/usr/local/apr/lib -lapr-1 -luuid -lcrypt -lpthread
$ PKG_CONFIG_PATH=/usr/local/apr/lib/pkgconfig pkg-config --modversion apr-util-1
1.6.5

# 通道三：libtool 构建系统（httpd 模块开发）
$ gcc app.c $(apr-1-config --link-libtool --libs)

$ APR=/usr/local/apr/bin/apr-1-config
$ APU=/usr/local/apr/bin/apu-1-config
$ gcc app.c $($APR --cflags --includes) $($APU --includes) \
      $($APR --link-ld) $($APU --link-ld) $($APU --libs) $($APR --libs)