Eliminate all uses of strcasecmp()

There weren't many uses and most can be done more efficiently.

configure.ac

@@ -244,40 +244,13 @@ dnl lround() with AC_CHECK_FUNCS, which just checks if it can be linked
 dnl against.  Some platforms are missing a prototype for lround(), so
 dnl both checks are useful.
 AC_CHECK_DECLS([lround], [], [], [[#include <math.h>]])
-dnl check for strcasecmp here as well as below - this one is to get
-dnl HAVE_STRCASECMP defined if appropriate (for img.c)
-AC_CHECK_FUNCS([popen getpwuid lround strcasecmp hypot mmap])
+AC_CHECK_FUNCS([popen getpwuid lround hypot mmap])
 
 dnl Much faster than using getc()/putc(), at least on Linux.
 AC_CHECK_FUNCS([getc_unlocked putc_unlocked])
 
 AC_CHECK_FUNCS([setenv unsetenv])
 
-dnl try to find a case-insensitive compare
-
-strcasecmp=no
-dnl The order of these tests is important.
-AC_CHECK_FUNC(strcasecmp, [strcasecmp=strcasecmp])
-if test no = "$strcasecmp"; then
-  AC_CHECK_FUNC(stricmp, [strcasecmp=stricmp])
-fi
-if test no = "$strcasecmp"; then
-  AC_CHECK_FUNC(strcmpi, [strcasecmp=strcmpi])
-fi
-
-AC_MSG_CHECKING([how to compare strings ignoring case])
-case $strcasecmp in
-no)
-  AC_LIBOBJ(strcasecmp)
-  AC_MSG_RESULT([using own implementation of strcasecmp]) ;;
-strcasecmp)
-  AC_MSG_RESULT([strcasecmp]) ;;
-*)
-  AC_DEFINE_UNQUOTED(strcasecmp, "$strcasecmp",
-    [strcasecmp define for systems which call it something else])
-  AC_MSG_RESULT([$strcasecmp]) ;;
-esac
-
 AC_PATH_PROG([JW], [jw], [$MISSING jw])
 AC_ARG_VAR([JW], [jw from docbook-utils/docbook-tools])
 

src/datain.c

@@ -591,10 +591,6 @@ nextch_handling_eol(void)
    }
 }
 
-#define LITLEN(S) (sizeof(S"") - 1)
-#define has_ext(F,L,E) ((L) > LITLEN(E) + 1 &&\
-			(F)[(L) - LITLEN(E) - 1] == FNM_SEP_EXT &&\
-			strcasecmp((F) + (L) - LITLEN(E), E) == 0)
 extern void
 data_file(const char *pth, const char *fnm)
 {
@@ -620,17 +616,24 @@ data_file(const char *pth, const char *fnm)
       }
 
       len = strlen(filename);
-      // Compass .clp is the same format as .dat, but contains loop-closed
-      // data.  This might be useful to read if you want to keep existing
-      // stations at the same adjusted positions, for example to be able to
-      // draw extensions on an existing drawn-up survey.  Or if you managed
-      // to lose the original .dat but still have the .clp.
-      if (has_ext(filename, len, "dat")) {
-	 fmt = FMT_DAT;
-      } else if (has_ext(filename, len, "clp")) {
-	 fmt = FMT_CLP;
-      } else if (has_ext(filename, len, "mak")) {
-	 fmt = FMT_MAK;
+      if (len > 4 && filename[len - 4] == FNM_SEP_EXT) {
+	  char ext[3];
+	  for (int i = 0; i <3; ++i) {
+	      ext[i] = tolower((unsigned char)filename[len - 3 + i]);
+	  }
+	  // Compass .clp is the same format as .dat, but contains
+	  // loop-closed data.  This might be useful to read if you want to
+	  // keep existing stations at the same adjusted positions, for
+	  // example to be able to draw extensions on an existing drawn-up
+	  // survey.  Or if you managed to lose the original .dat but still
+	  // have the .clp.
+	  if (memcmp(ext, "dat", 3) == 0) {
+	     fmt = FMT_DAT;
+	  } else if (memcmp(ext, "clp", 3) == 0) {
+	     fmt = FMT_CLP;
+	  } else if (memcmp(ext, "mak", 3) == 0) {
+	     fmt = FMT_MAK;
+	  }
       }
 
       file_store = file;

src/img.c

@@ -63,7 +63,6 @@
 # endif
 # define TIMEFMT "%a,%Y.%m.%d %H:%M:%S %Z"
 # define EXT_SVX_3D "3d"
-# define EXT_SVX_POS "pos"
 # define FNM_SEP_EXT '.'
 # define METRES_PER_FOOT 0.3048 /* exact value */
 # define xosmalloc(L) malloc((L))
@@ -273,29 +272,14 @@ my_lround(double x) {
 }
 #endif
 
-/* portable case insensitive string compare */
-#if defined(strcasecmp) || defined(HAVE_STRCASECMP)
-# define my_strcasecmp strcasecmp
-#else
-static int my_strcasecmp(const char *s1, const char *s2) {
-   unsigned char c1, c2;
-   do {
-      c1 = *s1++;
-      c2 = *s2++;
-   } while (c1 && toupper(c1) == toupper(c2));
-   /* now calculate real difference */
-   return c1 - c2;
-}
-#endif
-
 unsigned int img_output_version = IMG_VERSION_MAX;
 
 static img_errcode img_errno = IMG_NONE;
 
 #define FILEID "Survex 3D Image File"
 
-#define EXT_PLT "plt"
-#define EXT_PLF "plf"
+/* Encode extension into integer for fast testing. */
+#define EXT3(C1, C2, C3) (((C3) << 16) | ((C2) << 8) | (C1))
 
 /* Attempt to string paste to ensure we are passed a literal string */
 #define LITLEN(S) (sizeof(S"") - 1)
@@ -559,10 +543,6 @@ buf_included(img *pimg, const char *buf, size_t len)
     return pimg->survey_len == len && memcmp(buf, pimg->survey, len) == 0;
 }
 
-#define has_ext(F,L,E) ((L) > LITLEN(E) + 1 &&\
-			(F)[(L) - LITLEN(E) - 1] == FNM_SEP_EXT &&\
-			my_strcasecmp((F) + (L) - LITLEN(E), E) == 0)
-
 img *
 img_open_survey(const char *fnm, const char *survey)
 {
@@ -1059,6 +1039,7 @@ img_read_stream_survey(FILE *stream, int (*close_func)(FILE*),
    size_t len;
    char buf[LITLEN(FILEID) + 9];
    int ch;
+   UINT32_T ext;
 
    if (stream == NULL) {
       img_errno = IMG_FILENOTFOUND;
@@ -1152,18 +1133,29 @@ img_read_stream_survey(FILE *stream, int (*close_func)(FILE*),
    pimg->pending = 0;
 
    len = strlen(fnm);
-   if (has_ext(fnm, len, EXT_SVX_POS)) {
-pos_file:
-      pimg->version = VERSION_SURVEX_POS;
-      pimg->datestamp = my_strdup(TIMENA);
-      if (!pimg->datestamp) {
-	 goto out_of_memory_error;
-      }
-      pimg->start = 0;
-      goto successful_return;
+   /* Currently only 3 character extensions are tested below. */
+   ext = 0;
+   if (len > 4 && fnm[len - 4] == '.') {
+       /* Read extension and pack into ext. */
+       int i;
+       for (i = 1; i < 4; ++i) {
+	   unsigned char ext_ch = fnm[len - i];
+	   ext = (ext << 8) | tolower(ext_ch);
+       }
    }
+   switch (ext) {
+     case EXT3('p', 'o', 's'): /* Survex .pos */
+pos_file:
+       pimg->version = VERSION_SURVEX_POS;
+       pimg->datestamp = my_strdup(TIMENA);
+       if (!pimg->datestamp) {
+	   goto out_of_memory_error;
+       }
+       pimg->start = 0;
+       goto successful_return;
 
-   if (has_ext(fnm, len, EXT_PLT) || has_ext(fnm, len, EXT_PLF)) {
+     case EXT3('p', 'l', 't'): /* Compass .plt */
+     case EXT3('p', 'l', 'f'): /* Compass .plf */ {
        int result;
 plt_file:
        result = compass_plt_open(pimg);
@@ -1172,18 +1164,18 @@ img_read_stream_survey(FILE *stream, int (*close_func)(FILE*),
 	   goto error;
        }
        goto successful_return;
-   }
-
-   /* Although these are often referred to as "CMAP .XYZ files", it seems
-    * that actually, the extension .XYZ isn't used, rather .SHT (shot
-    * variant, produced by CMAP v16 and later), .UNA (unadjusted) and
-    * .ADJ (adjusted) extensions are.  Since img has long checked for
-    * .XYZ, we continue to do so in case anyone is relying on it.
-    */
-   if (has_ext(fnm, len, "sht") ||
-       has_ext(fnm, len, "adj") ||
-       has_ext(fnm, len, "una") ||
-       has_ext(fnm, len, "xyz")) {
+     }
+
+     /* Although these are often referred to as "CMAP .XYZ files", it seems
+      * that actually, the extension .XYZ isn't used, rather .SHT (shot
+      * variant, produced by CMAP v16 and later), .UNA (unadjusted) and .ADJ
+      * (adjusted) extensions are.  Since img has long checked for .XYZ, we
+      * continue to do so in case anyone is relying on it.
+      */
+     case EXT3('s', 'h', 't'): /* CMAP .sht */
+     case EXT3('a', 'd', 'j'): /* CMAP .adj */
+     case EXT3('u', 'n', 'a'): /* CMAP .una */
+     case EXT3('x', 'y', 'z'): /* CMAP .xyz */ {
        int result;
 xyz_file:
        result = cmap_xyz_open(pimg);
@@ -1192,6 +1184,7 @@ img_read_stream_survey(FILE *stream, int (*close_func)(FILE*),
 	   goto error;
        }
        goto successful_return;
+     }
    }
 
    if (fread(buf, LITLEN(FILEID) + 1, 1, pimg->fh) != 1 ||

src/msvc/config.h.in

@@ -38,9 +38,6 @@ typedef __int32 int32_t;
 typedef unsigned __int32 uint32_t;
 #endif
 
-/* strcasecmp define for systems which call it something else */
-#define strcasecmp stricmp
-
 /* Define if you have the mktime function.  */
 #define HAVE_MKTIME 1
 

src/survexport.cc

@@ -2,7 +2,7 @@
  * Convert a processed survey data file to another format.
  */
 
-/* Copyright (C) 1994-2004,2008,2010,2011,2013,2014,2018,2020,2022 Olly Betts
+/* Copyright (C) 1994-2024 Olly Betts
  * Copyright (C) 2004 John Pybus (SVG Output code)
  *
  * This program is free software; you can redistribute it and/or modify
@@ -26,6 +26,7 @@
 
 #define MSG_SETUP_PROJ_SEARCH_PATH 1
 
+#include <ctype.h>
 #include <math.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -63,7 +64,10 @@ main(int argc, char **argv)
    {
        /* Default to .pos output if installed as 3dtopos. */
        char* progname = baseleaf_from_fnm(argv[0]);
-       if (strcasecmp(progname, "3dtopos") == 0) {
+       for (char * p = progname; *p; ++p) {
+	   *p = tolower((unsigned char)*p);
+       }
+       if (strcmp(progname, "3dtopos") == 0) {
 	   format = FMT_POS;
        }
        osfree(progname);
@@ -389,11 +393,17 @@ main(int argc, char **argv)
       if (format == FMT_MAX_PLUS_ONE_) {
 	 // Select format based on extension.
 	 size_t len = strlen(fnm_out);
+	 // Length of longest extension of interest.
+	 constexpr size_t MAX_EXT_LEN = 4;
+	 char ext[MAX_EXT_LEN + 2];
+	 for (size_t i = 0; i < MAX_EXT_LEN + 2; ++i) {
+	     ext[i] = tolower((unsigned char)fnm_out[len - (MAX_EXT_LEN + 1) + i]);
+	 }
 	 for (size_t i = 0; i < FMT_MAX_PLUS_ONE_; ++i) {
 	    const auto& info = export_format_info[i];
 	    size_t l = strlen(info.extension);
 	    if (len > l + 1 &&
-		strcasecmp(fnm_out + len - l, info.extension) == 0) {
+		strcmp(ext + MAX_EXT_LEN + 1 - l, info.extension) == 0) {
 	       format = export_format(i);
 	       break;
 	    }