diff mcabber/mcabber/utils.c @ 1668:41c26b7d2890

Install mcabber headers * Change mcabber headers naming scheme * Move 'src/' -> 'mcabber/' * Add missing include <mcabber/config.h>'s * Create and install clean config.h version in 'include/' * Move "dirty" config.h version to 'mcabber/' * Add $(top_srcdir) to compiler include path * Update modules HOWTO
author Myhailo Danylenko <isbear@ukrpost.net>
date Mon, 18 Jan 2010 15:36:19 +0200
parents mcabber/src/utils.c@c3c7d6d0348f
children f02e7076ccec
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mcabber/mcabber/utils.c	Mon Jan 18 15:36:19 2010 +0200
@@ -0,0 +1,789 @@
+/*
+ * utils.c      -- Various utility functions
+ *
+ * Copyright (C) 2005-2009 Mikael Berthe <mikael@lilotux.net>
+ * Some of the ut_* functions are derived from Cabber debug/log code.
+ * from_iso8601() comes from the Pidgin (libpurple) project.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+ * USA
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+
+#ifdef HAVE_LIBIDN
+#include <idna.h>
+#include <stringprep.h>
+static char idnprep[1024];
+#endif
+
+#include <glib.h>
+#include <glib/gprintf.h>
+
+/* For Cygwin (thanks go to Yitzchak Scott-Thoennes) */
+#ifdef __CYGWIN__
+#  define timezonevar
+   extern long timezone;
+#endif
+#include <time.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <ctype.h>
+
+#include "utils.h"
+#include "logprint.h"
+
+static int DebugEnabled;
+static char *FName;
+
+//  jidtodisp(jid)
+// Strips the resource part from the jid
+// The caller should g_free the result after use.
+char *jidtodisp(const char *fjid)
+{
+  char *ptr;
+  char *alias;
+
+  alias = g_strdup(fjid);
+
+  if ((ptr = strchr(alias, JID_RESOURCE_SEPARATOR)) != NULL) {
+    *ptr = 0;
+  }
+  return alias;
+}
+
+char *jid_get_username(const char *fjid)
+{
+  char *ptr;
+  char *username;
+
+  username = g_strdup(fjid);
+  if ((ptr = strchr(username, JID_DOMAIN_SEPARATOR)) != NULL) {
+    *ptr = 0;
+  }
+  return username;
+}
+
+char *compose_jid(const char *username, const char *servername,
+                  const char *resource)
+{
+  char *fjid;
+
+  if (!strchr(username, JID_DOMAIN_SEPARATOR)) {
+    fjid = g_strdup_printf("%s%c%s%c%s", username,
+                           JID_DOMAIN_SEPARATOR, servername,
+                           JID_RESOURCE_SEPARATOR, resource);
+  } else {
+    fjid = g_strdup_printf("%s%c%s", username,
+                           JID_RESOURCE_SEPARATOR, resource);
+  }
+  return fjid;
+}
+
+gboolean jid_equal(const char *jid1, const char *jid2)
+{
+  char *a,*b;
+  int ret;
+  if (!jid1 && !jid2)
+    return TRUE;
+  if (!jid1 || !jid2)
+    return FALSE;
+
+  a = jidtodisp(jid1);
+  b = jidtodisp(jid2);
+  ret = strcasecmp(a, b);
+  g_free(a);
+  g_free(b);
+  return (ret == 0) ? TRUE : FALSE;
+}
+
+//  expand_filename(filename)
+// Expand "~/" with the $HOME env. variable in a file name.
+// The caller must free the string after use.
+char *expand_filename(const char *fname)
+{
+  if (!fname)
+    return NULL;
+  if (!strncmp(fname, "~/", 2)) {
+    char *homedir = getenv("HOME");
+    if (homedir)
+      return g_strdup_printf("%s%s", homedir, fname+1);
+  }
+  return g_strdup(fname);
+}
+
+void fingerprint_to_hex(const unsigned char *fpr, char hex[49])
+{
+  int i;
+  char *p;
+
+  for (p = hex, i = 0; i < 15; i++, p+=3)
+    g_sprintf(p, "%02X:", fpr[i]);
+  g_sprintf(p, "%02X", fpr[i]);
+  hex[48] = '\0';
+}
+
+gboolean hex_to_fingerprint(const char *hex, char fpr[16])
+{
+  int i;
+  char *p;
+
+  if (strlen(hex) != 47)
+    return FALSE;
+  for (i = 0, p = (char*)hex; *p && *(p+1); i++, p += 3)
+    fpr[i] = (char) g_ascii_strtoull (p, NULL, 16);
+  return TRUE;
+}
+
+void ut_InitDebug(int level, const char *filename)
+{
+  FILE *fp;
+  struct stat buf;
+  int err;
+
+  if (level < 1) {
+    DebugEnabled = 0;
+    FName = NULL;
+    return;
+  }
+
+  if (filename)
+    FName = expand_filename(filename);
+  else {
+    FName = getenv("HOME");
+    if (!FName)
+      FName = g_strdup("/tmp/mcabberlog");
+    else {
+      FName = g_strdup_printf("%s/mcabberlog", FName);
+    }
+  }
+
+  DebugEnabled = level;
+
+  fp = fopen(FName, "a");
+  if (!fp) {
+    fprintf(stderr, "ERROR: Cannot open tracelog file\n");
+    return;
+  }
+
+  err = fstat(fileno(fp), &buf);
+  if (err || buf.st_uid != geteuid()) {
+    fclose(fp);
+    DebugEnabled = 0;
+    FName = NULL;
+    if (err) {
+      fprintf(stderr, "ERROR: cannot stat the tracelog file!\n");
+    } else {
+      fprintf(stderr, "ERROR: tracelog file does not belong to you!\n");
+    }
+    return;
+  }
+  fchmod(fileno(fp), S_IRUSR|S_IWUSR);
+
+  fprintf(fp, "New trace log started.\n----------------------\n");
+  fclose(fp);
+}
+
+void ut_WriteLog(unsigned int flag, const char *data)
+{
+  if (!DebugEnabled || !FName) return;
+
+  if (((DebugEnabled >= 2) && (flag & (LPRINT_LOG|LPRINT_DEBUG))) ||
+      ((DebugEnabled == 1) && (flag & LPRINT_LOG))) {
+    FILE *fp = fopen(FName, "a+");
+    if (!fp) {
+      scr_LogPrint(LPRINT_NORMAL, "ERROR: Cannot open tracelog file");
+      return;
+    }
+    if (fputs(data, fp) == EOF)
+      scr_LogPrint(LPRINT_NORMAL, "ERROR: Cannot write to tracelog file");
+    fclose(fp);
+  }
+}
+
+//  checkset_perm(name, setmode)
+// Check the permissions of the "name" file/dir
+// If setmode is true, correct the permissions if they are wrong
+// Return values: -1 == bad file/dir, 0 == success, 1 == cannot correct
+int checkset_perm(const char *name, unsigned int setmode)
+{
+  int fd;
+  struct stat buf;
+
+#ifdef __CYGWIN__
+  // Permission checking isn't efficient on Cygwin
+  return 0;
+#endif
+
+  fd = stat(name, &buf);
+  if (fd == -1) return -1;
+
+  if (buf.st_uid != geteuid()) {
+    scr_LogPrint(LPRINT_LOGNORM, "Wrong file owner [%s]", name);
+    return 1;
+  }
+
+  if (buf.st_mode & (S_IRGRP | S_IWGRP | S_IXGRP) ||
+      buf.st_mode & (S_IROTH | S_IWOTH | S_IXOTH)) {
+    if (setmode) {
+      mode_t newmode = 0;
+      scr_LogPrint(LPRINT_LOGNORM, "Bad permissions [%s]", name);
+      if (S_ISDIR(buf.st_mode))
+        newmode |= S_IXUSR;
+      newmode |= S_IRUSR | S_IWUSR;
+      if (chmod(name, newmode)) {
+        scr_LogPrint(LPRINT_LOGNORM, "WARNING: Failed to correct permissions!");
+        return 1;
+      }
+      scr_LogPrint(LPRINT_LOGNORM, "Permissions have been corrected");
+    } else {
+      scr_LogPrint(LPRINT_LOGNORM, "WARNING: Bad permissions [%s]", name);
+      return 1;
+    }
+  }
+
+  return 0;
+}
+
+const char *ut_get_tmpdir(void)
+{
+  static const char *tmpdir;
+  const char *tmpvars[] = { "MCABBERTMPDIR", "TMP", "TMPDIR", "TEMP" };
+  unsigned int i;
+
+  if (tmpdir)
+    return tmpdir;
+
+  for (i = 0; i < (sizeof(tmpvars) / sizeof(const char *)); i++) {
+    tmpdir = getenv(tmpvars[i]);
+    if (tmpdir && tmpdir[0] && tmpdir[0] == '/' && tmpdir[1]) {
+      // Looks ok.
+      return tmpdir;
+    }
+  }
+
+  // Default temporary directory
+  tmpdir = "/tmp";
+  return tmpdir;
+}
+
+//  to_iso8601(dststr, timestamp)
+// Convert timestamp to iso8601 format, and store it in dststr.
+// NOTE: dststr should be at last 19 chars long.
+// Return should be 0
+int to_iso8601(char *dststr, time_t timestamp)
+{
+  struct tm *tm_time;
+  int ret;
+
+  tm_time = gmtime(&timestamp);
+
+  ret = snprintf(dststr, 19, "%.4d%02d%02dT%02d:%02d:%02dZ",
+        (int)(1900+tm_time->tm_year), tm_time->tm_mon+1, tm_time->tm_mday,
+        tm_time->tm_hour, tm_time->tm_min, tm_time->tm_sec);
+
+  return ((ret == -1) ? -1 : 0);
+}
+
+//  from_iso8601(timestamp, utc)
+// This function came from the Pidgin project, gaim_str_to_time().
+// (Actually date may not be pure iso-8601)
+// Thanks, guys!
+// ** Modified by somian 10 Apr 2006 with advice from ysth.
+time_t from_iso8601(const char *timestamp, int utc)
+{
+  struct tm t;
+  time_t retval = 0;
+  char buf[32];
+  char *c;
+  int tzoff = 0;
+  int hms_succ = 0;
+  int tmpyear;
+
+  time(&retval);
+  localtime_r(&retval, &t);
+
+  /* Reset time to midnight (00:00:00) */
+  t.tm_hour = t.tm_min = t.tm_sec = 0;
+
+  snprintf(buf, sizeof(buf), "%s", timestamp);
+  c = buf;
+
+  /* 4 digit year */
+  if (!sscanf(c, "%04d", &tmpyear)) return 0;
+  t.tm_year = tmpyear;
+  c+=4;
+  if (*c == '-')
+    c++;
+
+  t.tm_year -= 1900;
+
+  /* 2 digit month */
+  if (!sscanf(c, "%02d", &t.tm_mon)) return 0;
+  c+=2;
+  if (*c == '-')
+    c++;
+
+  t.tm_mon -= 1;
+
+  /* 2 digit day */
+  if (!sscanf(c, "%02d", &t.tm_mday)) return 0;
+  c+=2;
+  if (*c == 'T' || *c == '.') { /* we have more than a date, keep going */
+    c++; /* skip the "T" */
+
+    /* 2 digit hour */
+    if (sscanf(c, "%02d:%02d:%02d", &t.tm_hour, &t.tm_min, &t.tm_sec) == 3)
+    {
+      hms_succ = 1;
+      c += 8;
+    }
+    else if (sscanf(c, "%02d%02d%02d", &t.tm_hour, &t.tm_min, &t.tm_sec) == 3)
+    {
+       hms_succ = 1;
+       c += 6;
+    }
+
+    if (hms_succ) {
+      int tzhrs, tzmins;
+
+      if (*c == '.') /* dealing with precision we don't care about */
+        c += 4;
+
+      if ((*c == '+' || *c == '-') &&
+          sscanf(c+1, "%02d:%02d", &tzhrs, &tzmins)) {
+        tzoff = tzhrs*60*60 + tzmins*60;
+        if (*c == '+')
+          tzoff *= -1;
+      }
+
+      if (tzoff || utc) {
+#ifdef HAVE_TM_GMTOFF
+        tzoff += t.tm_gmtoff;
+#else
+#  ifdef HAVE_TIMEZONE
+        tzset();    /* making sure */
+        tzoff -= timezone;
+#  endif
+#endif
+      }
+    }
+  }
+
+  t.tm_isdst = -1;
+
+  retval = mktime(&t);
+
+  retval += tzoff;
+
+  return retval;
+}
+
+/**
+ * Derived from libjabber/jid.c, because the libjabber version is not
+ * really convenient for our usage.
+ *
+ * Check if the full JID is valid
+ * Return 0 if it is valid, non zero otherwise
+ */
+int check_jid_syntax(const char *fjid)
+{
+  const char *str;
+  const char *domain, *resource;
+  int domlen;
+#ifdef HAVE_LIBIDN
+  char *idnpp;
+  int r;
+#endif
+
+  if (!fjid) return 1;
+
+  domain = strchr(fjid, JID_DOMAIN_SEPARATOR);
+
+  /* the username is optional */
+  if (!domain) {
+    domain = fjid;
+  } else {
+    /* node identifiers may not be longer than 1023 bytes */
+    if ((domain == fjid) || (domain-fjid > 1023))
+      return 1;
+    domain++;
+
+#ifdef HAVE_LIBIDN
+    idnpp = idnprep;
+    str = fjid;
+    while (*str != JID_DOMAIN_SEPARATOR)
+      *idnpp++ = *str++;
+    *idnpp = 0;
+
+    r = stringprep(idnprep, 1023, 0, stringprep_xmpp_nodeprep);
+    if (r != STRINGPREP_OK || !idnprep[0])
+      return 1;
+    /* the username looks okay */
+#else
+    /* check for low and invalid ascii characters in the username */
+    for (str = fjid; *str != JID_DOMAIN_SEPARATOR; str++) {
+      if (*str <= ' ' || *str == ':' || *str == JID_DOMAIN_SEPARATOR ||
+              *str == '<' || *str == '>' || *str == '\'' ||
+              *str == '"' || *str == '&') {
+        return 1;
+      }
+    }
+    /* the username is okay as far as we can tell without LIBIDN */
+#endif
+  }
+
+  resource = strchr(domain, JID_RESOURCE_SEPARATOR);
+
+  /* the resource is optional */
+  if (resource) {
+    domlen = resource - domain;
+    resource++;
+    /* resources may not be longer than 1023 bytes */
+    if ((*resource == '\0') || strlen(resource) > 1023)
+      return 1;
+#ifdef HAVE_LIBIDN
+    strncpy(idnprep, resource, sizeof(idnprep));
+    r = stringprep(idnprep, 1023, 0, stringprep_xmpp_resourceprep);
+    if (r != STRINGPREP_OK || !idnprep[0])
+      return 1;
+#endif
+  } else {
+    domlen = strlen(domain);
+  }
+
+  /* there must be a domain identifier */
+  if (domlen == 0) return 1;
+
+  /* and it must not be longer than 1023 bytes */
+  if (domlen > 1023) return 1;
+
+#ifdef HAVE_LIBIDN
+  idnpp = idnprep;
+  str = domain;
+  while (*str != '\0' && *str != JID_RESOURCE_SEPARATOR)
+    *idnpp++ = *str++;
+  *idnpp = 0;
+
+  r = stringprep_nameprep(idnprep, 1023);
+  if (r != STRINGPREP_OK || !idnprep[0])
+    return 1;
+
+  if (idna_to_ascii_8z(idnprep, &idnpp, IDNA_USE_STD3_ASCII_RULES) !=
+      IDNA_SUCCESS)
+    return 1;
+  else
+    free(idnpp);
+#else
+  /* make sure the hostname is valid characters */
+  for (str = domain; *str != '\0' && *str != JID_RESOURCE_SEPARATOR; str++) {
+    if (!(isalnum(*str) || *str == '.' || *str == '-' || *str == '_'))
+      return 1;
+  }
+#endif
+
+  /* it's okay as far as we can tell */
+  return 0;
+}
+
+
+inline void mc_strtolower(char *str)
+{
+  if (!str) return;
+  for ( ; *str; str++)
+    *str = tolower(*str);
+}
+
+//  strip_arg_special_chars(string)
+// Remove quotes and backslashes before an escaped quote
+// Only quotes need a backslash
+// Ex.: ["a b"] -> [a b]; [a\"b] -> [a"b]
+void strip_arg_special_chars(char *s)
+{
+  int instring = FALSE;
+  int escape = FALSE;
+  char *p;
+
+  if (!s) return;
+
+  for (p = s; *p; p++) {
+    if (*p == '"') {
+      if (!escape) {
+        instring = !instring;
+        strcpy(p, p+1);
+        p--;
+      } else
+        escape = FALSE;
+    } else if (*p == '\\') {
+      if (!escape) {
+        strcpy(p, p+1);
+        p--;
+      }
+      escape = !escape;
+    } else
+      escape = FALSE;
+  }
+}
+
+//  split_arg(arg, n, preservelast)
+// Split the string arg into a maximum of n pieces, taking care of
+// double quotes.
+// Return a null-terminated array of strings.  This array should be freed
+// by the caller after use, for example with free_arg_lst().
+// If dontstriplast is true, the Nth argument isn't stripped (i.e. no
+// processing of quote chars)
+char **split_arg(const char *arg, unsigned int n, int dontstriplast)
+{
+  char **arglst;
+  const char *p, *start, *end;
+  unsigned int i = 0;
+  int instring = FALSE;
+  int escape = FALSE;
+
+  arglst = g_new0(char*, n+1);
+
+  if (!arg || !n) return arglst;
+
+  // Skip leading space
+  for (start = arg; *start && *start == ' '; start++) ;
+  // End of string pointer
+  for (end = start; *end; end++) ;
+  // Skip trailing space
+  while (end > start+1 && *(end-1) == ' ')
+    end--;
+
+  for (p = start; p < end; p++) {
+    if (*p == '"' && !escape)
+      instring = !instring;
+    if (*p == '\\' && !escape)
+      escape = TRUE;
+    else if (escape)
+      escape = FALSE;
+    if (*p == ' ' && !instring && i+1 < n) {
+      // end of parameter
+      *(arglst+i) = g_strndup(start, p-start);
+      strip_arg_special_chars(*(arglst+i));
+      for (start = p+1; *start && *start == ' '; start++) ;
+      p = start-1;
+      i++;
+    }
+  }
+
+  if (start < end) {
+    *(arglst+i) = g_strndup(start, end-start);
+    if (!dontstriplast || i+1 < n)
+      strip_arg_special_chars(*(arglst+i));
+  }
+
+  return arglst;
+}
+
+//  free_arg_lst(arglst)
+// Free an array allocated by split_arg()
+void free_arg_lst(char **arglst)
+{
+  char **arg_elt;
+
+  for (arg_elt = arglst; *arg_elt; arg_elt++)
+    g_free(*arg_elt);
+  g_free(arglst);
+}
+
+//  replace_nl_with_dots(bufstr)
+// Replace '\n' with "(...)" (or with a NUL if the string is too short)
+void replace_nl_with_dots(char *bufstr)
+{
+  char *p = strchr(bufstr, '\n');
+  if (p) {
+    if (strlen(p) >= 5)
+      strcpy(p, "(...)");
+    else
+      *p = 0;
+  }
+}
+
+//  ut_expand_tabs(text)
+// Expand tabs and filter out some bad chars in string text.
+// If there is no tab and no bad chars in the string, a pointer to text
+// is returned (be careful _not_ to free the pointer in this case).
+// If there are some tabs or bad chars, a new string with expanded chars
+// and no bad chars is returned; this is up to the caller to free this
+// string after use.
+char *ut_expand_tabs(const char *text)
+{
+  char *xtext, *linestart;
+  char *p, *q;
+  guint n = 0, bc = 0;
+
+  xtext = (char*)text;
+  for (p=xtext; *p; p++)
+    if (*p == '\t')
+      n++;
+    else if (*p == '\x0d')
+      bc++;
+  // XXX Are there other special chars we should filter out?
+
+  if (!n && !bc)
+    return (char*)text;
+
+  xtext = g_new(char, strlen(text) + 1 + 8*n);
+  p = (char*)text;
+  q = linestart = xtext;
+  do {
+    if (*p == '\t') {
+      do { *q++ = ' '; } while ((q-linestart)%8);
+    } else if (*p != '\x0d') {
+      *q++ = *p;
+      if (*p =='\n')
+        linestart = q;
+    }
+  } while (*p++);
+
+  return xtext;
+}
+
+
+/* Cygwin's newlib does not have strcasestr() */
+/* The author of the code before the endif is
+ *    Jeffrey Stedfast <fejj@ximian.com>
+ * and this code is reusable in compliance with the GPL v2. -- somian */
+
+#if !defined(HAVE_STRCASESTR)
+
+#  define lowercase(c)  (isupper ((int) (c)) ? tolower ((int) (c)) : (int) (c))
+#  define bm_index(c, icase)      ((icase) ? lowercase (c) : (int) (c))
+#  define bm_equal(c1, c2, icase) ((icase) ? lowercase (c1) == lowercase (c2) : (c1) == (c2))
+
+/* FIXME: this is just a guess... should really do some performace tests to get an accurate measure */
+#  define bm_optimal(hlen, nlen)  (((hlen) ? (hlen) > 20 : 1) && (nlen) > 10 ? 1 : 0)
+
+static unsigned char *
+__boyer_moore (const unsigned char *haystack, size_t haystacklen,
+               const unsigned char *needle, size_t needlelen, int icase)
+{
+  register unsigned char *hc_ptr, *nc_ptr;
+  unsigned char *he_ptr, *ne_ptr, *h_ptr;
+  size_t skiptable[256], n;
+  register int i;
+
+#ifdef BOYER_MOORE_CHECKS
+  /* we don't need to do these checks since memmem/strstr/etc do it already */
+  /* if the haystack is shorter than the needle then we can't possibly match */
+  if (haystacklen < needlelen)
+    return NULL;
+
+  /* instant match if the pattern buffer is 0-length */
+  if (needlelen == 0)
+    return (unsigned char *) haystack;
+#endif /* BOYER_MOORE_CHECKS */
+
+  /* set a pointer at the end of each string */
+  ne_ptr = (unsigned char *) needle + needlelen - 1;
+  he_ptr = (unsigned char *) haystack + haystacklen - 1;
+
+  /* create our skip table */
+  for (i = 0; i < 256; i++)
+    skiptable[i] = needlelen;
+  for (nc_ptr = (unsigned char *) needle; nc_ptr < ne_ptr; nc_ptr++)
+    skiptable[bm_index (*nc_ptr, icase)] = (size_t) (ne_ptr - nc_ptr);
+
+  h_ptr = (unsigned char *) haystack;
+  while (haystacklen >= needlelen) {
+    hc_ptr = h_ptr + needlelen - 1;   /* set the haystack compare pointer */
+    nc_ptr = ne_ptr;                  /* set the needle compare pointer */
+
+    /* work our way backwards till they don't match */
+    for (i = 0; nc_ptr > (unsigned char *) needle; nc_ptr--, hc_ptr--, i++)
+      if (!bm_equal (*nc_ptr, *hc_ptr, icase))
+        break;
+
+    if (!bm_equal (*nc_ptr, *hc_ptr, icase)) {
+      n = skiptable[bm_index (*hc_ptr, icase)];
+      if (n == needlelen && i)
+        if (bm_equal (*ne_ptr, ((unsigned char *) needle)[0], icase))
+          n--;
+      h_ptr += n;
+      haystacklen -= n;
+    } else
+      return (unsigned char *) h_ptr;
+  }
+
+  return NULL;
+}
+
+/*
+ * strcasestr:
+ * @haystack: string to search
+ * @needle: substring to search for
+ *
+ * Finds the first occurence of the substring @needle within the
+ * string @haystack ignoring case.
+ *
+ * Returns a pointer to the beginning of the substring match within
+ * @haystack, or NULL if the substring is not found.
+ **/
+char *
+strcasestr (const char *haystack, const char *needle)
+{
+  register unsigned char *h, *n, *hc, *nc;
+  size_t needlelen;
+
+  needlelen = strlen (needle);
+
+  if (needlelen == 0) {
+    return (char *) haystack;
+  } else if (bm_optimal (0, needlelen)) {
+    return (char *) __boyer_moore ((const unsigned char *) haystack,
+                                   strlen (haystack),
+                                   (const unsigned char *) needle,
+                                   needlelen, 1);
+  }
+
+  h = (unsigned char *) haystack;
+  n = (unsigned char *) needle;
+
+  while (*(h + needlelen - 1)) {
+    if (lowercase (*h) == lowercase (*n)) {
+      for (hc = h + 1, nc = n + 1; *hc && *nc; hc++, nc++)
+        if (lowercase (*hc) != lowercase (*nc))
+          break;
+
+      if (!*nc)
+        return (char *) h;
+    }
+    h++;
+  }
+  return NULL;
+}
+#endif /* !HAVE_STRCASESTR */
+
+//  startswith(str, word, ignore_case)
+// Returns TRUE if string str starts with word.
+int startswith(const char *str, const char *word, guint ignore_case)
+{
+  if (ignore_case && !strncasecmp(str, word, strlen(word)))
+    return TRUE;
+  else if (!ignore_case && !strncmp(str, word, strlen(word)))
+    return TRUE;
+  return FALSE;
+}
+
+/* vim: set expandtab cindent cinoptions=>2\:2(0:  For Vim users... */