AC_CHECK_(FUNCS|HEADERS): sort arguments removing duplicates

configure.ac

@@ -358,17 +358,17 @@ dnl ---------------------------------------------------------------------------
 AC_HEADER_DIRENT
 AC_HEADER_STDC
 AC_CHECK_HEADERS([m4_normalize([
-  sys/param.h
-  sys/mman.h
-  sys/select.h
-  locale.h
-  memory.h
   getopt.h
-  unistd.h
-  mcheck.h
+  langinfo.h
   limits.h
+  locale.h
+  mcheck.h
+  memory.h
+  sys/mman.h
+  sys/param.h
+  sys/select.h
   sys/time.h
-  langinfo.h
+  unistd.h
 ])])
 
 dnl If sys/mman.h is present, check whether mmap requires the mman
@@ -400,20 +400,20 @@ AC_CHECK_FUNCS([m4_normalize([
   getenv
   getopt
   getopt_long
+  gmtime_r
+  inet_aton
+  localtime_r
+  lstat
   mkdir
+  rand_r
   setenv
-  strdup
-  strncpy
-  strcpy
   snprintf
   sprintf
-  vsnprintf
-  gmtime_r
   statvfs
-  localtime_r
-  lstat
-  inet_aton
-  rand_r
+  strcpy
+  strdup
+  strncpy
+  vsnprintf
 ])])
 
 dnl Find out how to get struct tm

libgphoto2_port/configure.ac

@@ -160,33 +160,30 @@ AC_C_INLINE([])
 AC_C_CONST([])
 
 AC_CHECK_HEADERS([m4_normalize([
-  stdlib.h
-  unistd.h
-  stdio.h
-  fcntl.h
+  asm/io.h
+  byteswap.h
+  endian.h
   errno.h
-  sys/time.h
-  sys/param.h
-  sys/select.h
-  termios.h
-  sgetty.h
-  ttold.h
-  ioctl-types.h
   fcntl.h
+  ioctl-types.h
+  limits.h
+  mntent.h
+  scsi/sg.h
+  sgetty.h
   sgtty.h
+  stdio.h
+  stdlib.h
+  sys/file.h
   sys/ioctl.h
+  sys/mntent.h
+  sys/mnttab.h
+  sys/param.h
+  sys/select.h
   sys/time.h
   termio.h
+  termios.h
+  ttold.h
   unistd.h
-  endian.h
-  byteswap.h
-  asm/io.h
-  mntent.h
-  sys/mntent.h
-  sys/mnttab.h
-  scsi/sg.h
-  limits.h
-  sys/file.h
 ])])
 
 dnl FIXME: Provide regex.h with the corresponding object code for
@@ -241,12 +238,12 @@ mt.mnt_mountp;
 
 dnl Checks for library functions.
 AC_CHECK_FUNCS([m4_normalize([
-  setmntent
   endmntent
-  strerror
+  flock
+  setmntent
   snprintf
+  strerror
   vsnprintf
-  flock
 ])])
 
 dnl Check if TIOCM_RTS is included in one of several possible files