diff --git a/.gitignore b/.gitignore
index 03df200f01..a1bbe1eab8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,242 +1,243 @@
 # Common
 \#*
 .\#*
 GPATH
 GRTAGS
 GTAGS
 TAGS
 Makefile
 Makefile.in
 .deps
 .dirstamp
 .libs
 *.pc
 *.pyc
 *.bz2
 *.tar.gz
 *.tgz
 *.la
 *.lo
 *.o
 *~
 *.gcda
 *.gcno
 
 
 # Autobuild
 aclocal.m4
 autoconf
 autoheader
 autom4te.cache/
 automake
 build.counter
 compile
 /confdefs.h
 config.guess
 config.log
 config.status
 config.sub
 configure
 /conftest*
 depcomp
 install-sh
 include/stamp-*
 libtool
 libtool.m4
 ltdl.m4
 libltdl
 ltmain.sh
 missing
 py-compile
 /m4/argz.m4
 /m4/ltargz.m4
 /m4/ltoptions.m4
 /m4/ltsugar.m4
 /m4/ltversion.m4
 /m4/lt~obsolete.m4
 test-driver
 ylwrap
 
 # Configure targets
 /cts/CTS.py
 /cts/CTSlab.py
 /cts/CTSvars.py
 /cts/LSBDummy
 /cts/OCFIPraTest.py
 /cts/benchmark/clubench
 /cts/cluster_test
 /cts/cts
 /cts/cts-cli
 /cts/cts-coverage
 /cts/cts-exec
 /cts/cts-fencing
 /cts/cts-log-watcher
 /cts/cts-regression
 /cts/cts-scheduler
 /cts/cts-support
 /cts/fence_dummy
 /cts/lxc_autogen.sh
 /cts/pacemaker-cts-dummyd
 /cts/pacemaker-cts-dummyd@.service
 /daemons/execd/pacemaker_remote
 /daemons/execd/pacemaker_remote.service
 /daemons/fenced/fence_legacy
 /daemons/pacemakerd/pacemaker
 /daemons/pacemakerd/pacemaker.combined.upstart
 /daemons/pacemakerd/pacemaker.service
 /daemons/pacemakerd/pacemaker.upstart
 /doc/Doxyfile
 /extra/logrotate/pacemaker
 /extra/resources/ClusterMon
 /extra/resources/HealthSMART
 /extra/resources/SysInfo
 /extra/resources/ifspeed
 /extra/resources/o2cb
 include/config.h
 include/config.h.in
 include/crm_config.h
 publican.cfg
 /tools/cibsecret
 /tools/crm_error
 /tools/crm_failcount
 /tools/crm_master
 /tools/crm_mon.service
 /tools/crm_mon.upstart
 /tools/crm_report
 /tools/crm_rule
 /tools/crm_standby
 /tools/pcmk_simtimes
 /tools/report.collector
 /tools/report.common
 
 # Build targets
 *.7
 *.7.xml
 *.7.html
 *.8
 *.8.xml
 *.8.html
 /daemons/attrd/pacemaker-attrd
 /daemons/based/pacemaker-based
 /daemons/based/cibmon
 /daemons/controld/pacemaker-controld
 /daemons/execd/cts-exec-helper
 /daemons/execd/pacemaker-execd
 /daemons/execd/pacemaker-remoted
 /daemons/fenced/cts-fence-helper
 /daemons/fenced/pacemaker-fenced
 /daemons/fenced/pacemaker-fenced.xml
 /daemons/pacemakerd/pacemakerd
 /daemons/schedulerd/pacemaker-schedulerd
 /daemons/schedulerd/pacemaker-schedulerd.xml
 /doc/*/tmp/**
 /doc/*/publish
 /doc/*.build
 /doc/*/en-US/Ap-*.xml
 /doc/*/en-US/Ch-*.xml
 /doc/.ABI-build
 /doc/HTML
 /doc/abi_dumps
 /doc/abi-check
 /doc/api/*
 /doc/compat_reports
 /doc/crm_fencing.html
 /doc/publican-catalog*
 /doc/shared/en-US/*.xml
 /doc/shared/en-US/images/pcmk-*.png
 /doc/shared/en-US/images/Policy-Engine-*.png
 /doc/sphinx/*/_build
 /doc/sphinx/*/conf.py
 /lib/common/md5.c
 /maint/testcc_helper.cc
 /maint/testcc_*_h
 /maint/mocked/based
 scratch
 /tools/attrd_updater
 /tools/cibadmin
 /tools/crmadmin
 /tools/crm_attribute
 /tools/crm_diff
 /tools/crm_mon
 /tools/crm_node
 /tools/crm_resource
 /tools/crm_shadow
 /tools/crm_simulate
 /tools/crm_ticket
 /tools/crm_verify
 /tools/iso8601
 /tools/stonith_admin
 xml/crm.dtd
 xml/pacemaker*.rng
 xml/versions.rng
 xml/api/api-result*.rng
 lib/gnu/libgnu.a
 lib/gnu/stdalign.h
 *.coverity
 
 # Packager artifacts
 *.rpm
 /mock
 /pacemaker.spec
 /rpm/[A-Z]*
 
 # make dist/export working directory
 pacemaker-[a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9]
 
 # Test detritus
 /cts/.regression.failed.diff
 /cts/scheduler/*.ref
 /cts/scheduler/*.up
 /cts/scheduler/*.up.err
 /cts/scheduler/bug-rh-1097457.log
 /cts/scheduler/bug-rh-1097457.trs
 /cts/scheduler/shadow.*
 /cts/test-suite.log
 /xml/test-*/*.up
 /xml/test-*/*.up.err
 /xml/assets/*.rng
 /xml/assets/diffview.js
 /xml/assets/xmlcatalog
 
 # Test results
 *.log
 *.trs
 /lib/common/tests/strings/pcmk__parse_ll_range
 /lib/common/tests/strings/pcmk__str_any_of
+/lib/common/tests/strings/pcmk__strcmp
 /lib/common/tests/utils/pcmk_str_is_infinity
 /lib/common/tests/utils/pcmk_str_is_minus_infinity
 /lib/pengine/tests/rules/pe_cron_range_satisfied
 
 # Release maintenance detritus
 /maint/gnulib
 
 # Formerly built files (helps when jumping back and forth in checkout)
 /.ABI-build
 /Doxyfile
 /HTML
 /abi_dumps
 /abi-check
 /compat_reports
 /attrd
 /cib
 /coverage.sh
 /crmd
 /cts/HBDummy
 /doc/Clusters_from_Scratch.txt
 /doc/Pacemaker_Explained.txt
 /doc/acls.html
 /fencing
 /lrmd
 /mcp
 /pacemaker-*.spec
 /pengine
 
 #Other 
 coverity-*
 logs
 *.patch
 *.diff
 *.sed
 *.orig
 *.rej
 *.swp
diff --git a/include/crm/common/strings_internal.h b/include/crm/common/strings_internal.h
index 8aca4ff9de..5d3cda4bb5 100644
--- a/include/crm/common/strings_internal.h
+++ b/include/crm/common/strings_internal.h
@@ -1,62 +1,77 @@
 /*
  * Copyright 2015-2020 the Pacemaker project contributors
  *
  * The version control history for this file may have further details.
  *
  * This source code is licensed under the GNU Lesser General Public License
  * version 2.1 or later (LGPLv2.1+) WITHOUT ANY WARRANTY.
  */
 
 #ifndef PCMK__STRINGS_INTERNAL__H
 #define PCMK__STRINGS_INTERNAL__H
 
 #include <stdbool.h>            // bool
 
 #include <glib.h>               // guint, GList, GHashTable
 
 /* internal generic string functions (from strings.c) */
 
+enum pcmk__str_flags {
+    pcmk__str_none          = 0,
+    pcmk__str_casei         = 1 << 0,
+    pcmk__str_null_matches  = 1 << 1,
+    pcmk__str_regex         = 1 << 2
+};
+
 int pcmk__guint_from_hash(GHashTable *table, const char *key, guint default_val,
                           guint *result);
 bool pcmk__starts_with(const char *str, const char *prefix);
 bool pcmk__ends_with(const char *s, const char *match);
 bool pcmk__ends_with_ext(const char *s, const char *match);
 char *pcmk__add_word(char *list, const char *word);
 int pcmk__compress(const char *data, unsigned int length, unsigned int max,
                    char **result, unsigned int *result_len);
 
 int pcmk__parse_ll_range(const char *srcstring, long long *start, long long *end);
 gboolean pcmk__str_in_list(GList *lst, const gchar *s);
 
 bool pcmk__str_any_of(const char *s, ...) G_GNUC_NULL_TERMINATED;
 
+int pcmk__strcmp(const char *s1, const char *s2, uint32_t flags);
+
+static inline bool
+pcmk__str_eq(const char *s1, const char *s2, uint32_t flags)
+{
+    return pcmk__strcmp(s1, s2, flags) == 0;
+}
+
 /* Correctly displaying singular or plural is complicated; consider "1 node has"
  * vs. "2 nodes have". A flexible solution is to pluralize entire strings, e.g.
  *
  * if (a == 1) {
  *     crm_info("singular message"):
  * } else {
  *     crm_info("plural message");
  * }
  *
  * though even that's not sufficient for all languages besides English (if we
  * ever desire to do translations of output and log messages). But the following
  * convenience macros are "good enough" and more concise for many cases.
  */
 
 /* Example:
  * crm_info("Found %d %s", nentries,
  *          pcmk__plural_alt(nentries, "entry", "entries"));
  */
 #define pcmk__plural_alt(i, s1, s2) (((i) == 1)? (s1) : (s2))
 
 // Example: crm_info("Found %d node%s", nnodes, pcmk__plural_s(nnodes));
 #define pcmk__plural_s(i) pcmk__plural_alt(i, "", "s")
 
 static inline int
 pcmk__str_empty(const char *s)
 {
     return (s == NULL) || (s[0] == '\0');
 }
 
 #endif /* PCMK__STRINGS_INTERNAL__H */
diff --git a/lib/common/strings.c b/lib/common/strings.c
index aaea3c9700..9ad5c85302 100644
--- a/lib/common/strings.c
+++ b/lib/common/strings.c
@@ -1,759 +1,852 @@
 /*
  * Copyright 2004-2020 the Pacemaker project contributors
  *
  * The version control history for this file may have further details.
  *
  * This source code is licensed under the GNU Lesser General Public License
  * version 2.1 or later (LGPLv2.1+) WITHOUT ANY WARRANTY.
  */
 
 #include <crm_internal.h>
 
 #ifndef _GNU_SOURCE
 #  define _GNU_SOURCE
 #endif
 
+#include <regex.h>
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
 #include <ctype.h>
 #include <limits.h>
 #include <bzlib.h>
 #include <sys/types.h>
 
 char *
 crm_itoa_stack(int an_int, char *buffer, size_t len)
 {
     if (buffer != NULL) {
         snprintf(buffer, len, "%d", an_int);
     }
 
     return buffer;
 }
 
 /*!
  * \internal
  * \brief Scan a long long integer from a string
  *
  * \param[in]  text      String to scan
  * \param[out] result    If not NULL, where to store scanned value
  * \param[out] end_text  If not NULL, where to store pointer to just after value
  *
  * \return Standard Pacemaker return code (also set errno on error)
  */
 static int
 scan_ll(const char *text, long long *result, char **end_text)
 {
     long long local_result = -1;
     char *local_end_text = NULL;
     int rc = pcmk_rc_ok;
 
     errno = 0;
     if (text != NULL) {
 #ifdef ANSI_ONLY
         local_result = (long long) strtol(text, &local_end_text, 10);
 #else
         local_result = strtoll(text, &local_end_text, 10);
 #endif
         if (errno == ERANGE) {
             rc = errno;
             crm_warn("Integer parsed from %s was clipped to %lld",
                      text, local_result);
 
         } else if (errno != 0) {
             rc = errno;
             local_result = -1;
             crm_err("Could not parse integer from %s (using -1 instead): %s",
                     text, pcmk_rc_str(rc));
 
         } else if (local_end_text == text) {
             rc = EINVAL;
             local_result = -1;
             crm_err("Could not parse integer from %s (using -1 instead): "
                     "No digits found", text);
         }
 
         if ((end_text == NULL) && (local_end_text != NULL)
             && (local_end_text[0] != '\0')) {
             crm_warn("Characters left over after parsing '%s': '%s'",
                      text, local_end_text);
         }
         errno = rc;
     }
     if (end_text != NULL) {
         *end_text = local_end_text;
     }
     if (result != NULL) {
         *result = local_result;
     }
     return rc;
 }
 
 /*!
  * \brief Parse a long long integer value from a string
  *
  * \param[in] text          The string to parse
  * \param[in] default_text  Default string to parse if text is NULL
  *
  * \return Parsed value on success, -1 (and set errno) on error
  */
 long long
 crm_parse_ll(const char *text, const char *default_text)
 {
     long long result;
 
     if (text == NULL) {
         text = default_text;
         if (text == NULL) {
             crm_err("No default conversion value supplied");
             errno = EINVAL;
             return -1;
         }
     }
     scan_ll(text, &result, NULL);
     return result;
 }
 
 /*!
  * \brief Parse an integer value from a string
  *
  * \param[in] text          The string to parse
  * \param[in] default_text  Default string to parse if text is NULL
  *
  * \return Parsed value on success, INT_MIN or INT_MAX (and set errno to ERANGE)
  *         if parsed value is out of integer range, otherwise -1 (and set errno)
  */
 int
 crm_parse_int(const char *text, const char *default_text)
 {
     long long result = crm_parse_ll(text, default_text);
 
     if (result < INT_MIN) {
         // If errno is ERANGE, crm_parse_ll() has already logged a message
         if (errno != ERANGE) {
             crm_err("Conversion of %s was clipped: %lld", text, result);
             errno = ERANGE;
         }
         return INT_MIN;
 
     } else if (result > INT_MAX) {
         // If errno is ERANGE, crm_parse_ll() has already logged a message
         if (errno != ERANGE) {
             crm_err("Conversion of %s was clipped: %lld", text, result);
             errno = ERANGE;
         }
         return INT_MAX;
     }
 
     return (int) result;
 }
 
 /*!
  * \internal
  * \brief Parse a guint from a string stored in a hash table
  *
  * \param[in]  table        Hash table to search
  * \param[in]  key          Hash table key to use to retrieve string
  * \param[in]  default_val  What to use if key has no entry in table
  * \param[out] result       If not NULL, where to store parsed integer
  *
  * \return Standard Pacemaker return code
  */
 int
 pcmk__guint_from_hash(GHashTable *table, const char *key, guint default_val,
                       guint *result)
 {
     const char *value;
     long long value_ll;
 
     CRM_CHECK((table != NULL) && (key != NULL), return EINVAL);
 
     value = g_hash_table_lookup(table, key);
     if (value == NULL) {
         if (result != NULL) {
             *result = default_val;
         }
         return pcmk_rc_ok;
     }
 
     errno = 0;
     value_ll = crm_parse_ll(value, NULL);
     if (errno != 0) {
         return errno; // Message already logged
     }
     if ((value_ll < 0) || (value_ll > G_MAXUINT)) {
         crm_warn("Could not parse non-negative integer from %s", value);
         return ERANGE;
     }
 
     if (result != NULL) {
         *result = (guint) value_ll;
     }
     return pcmk_rc_ok;
 }
 
 #ifndef NUMCHARS
 #  define	NUMCHARS	"0123456789."
 #endif
 
 #ifndef WHITESPACE
 #  define	WHITESPACE	" \t\n\r\f"
 #endif
 
 /*!
  * \brief Parse a time+units string and return milliseconds equivalent
  *
  * \param[in] input  String with a number and units (optionally with whitespace
  *                   before and/or after the number)
  *
  * \return Milliseconds corresponding to string expression, or -1 on error
  */
 long long
 crm_get_msec(const char *input)
 {
     const char *num_start = NULL;
     const char *units;
     long long multiplier = 1000;
     long long divisor = 1;
     long long msec = -1;
     size_t num_len = 0;
     char *end_text = NULL;
 
     if (input == NULL) {
         return -1;
     }
 
     num_start = input + strspn(input, WHITESPACE);
     num_len = strspn(num_start, NUMCHARS);
     if (num_len < 1) {
         return -1;
     }
     units = num_start + num_len;
     units += strspn(units, WHITESPACE);
 
     if (!strncasecmp(units, "ms", 2) || !strncasecmp(units, "msec", 4)) {
         multiplier = 1;
         divisor = 1;
     } else if (!strncasecmp(units, "us", 2) || !strncasecmp(units, "usec", 4)) {
         multiplier = 1;
         divisor = 1000;
     } else if (!strncasecmp(units, "s", 1) || !strncasecmp(units, "sec", 3)) {
         multiplier = 1000;
         divisor = 1;
     } else if (!strncasecmp(units, "m", 1) || !strncasecmp(units, "min", 3)) {
         multiplier = 60 * 1000;
         divisor = 1;
     } else if (!strncasecmp(units, "h", 1) || !strncasecmp(units, "hr", 2)) {
         multiplier = 60 * 60 * 1000;
         divisor = 1;
     } else if ((*units != EOS) && (*units != '\n') && (*units != '\r')) {
         return -1;
     }
 
     scan_ll(num_start, &msec, &end_text);
     if (msec > (LLONG_MAX / multiplier)) {
         // Arithmetics overflow while multiplier/divisor mutually exclusive
         return LLONG_MAX;
     }
     msec *= multiplier;
     msec /= divisor;
     return msec;
 }
 
 gboolean
 safe_str_neq(const char *a, const char *b)
 {
     if (a == b) {
         return FALSE;
 
     } else if (a == NULL || b == NULL) {
         return TRUE;
 
     } else if (strcasecmp(a, b) == 0) {
         return FALSE;
     }
     return TRUE;
 }
 
 gboolean
 crm_is_true(const char *s)
 {
     gboolean ret = FALSE;
 
     if (s != NULL) {
         crm_str_to_boolean(s, &ret);
     }
     return ret;
 }
 
 int
 crm_str_to_boolean(const char *s, int *ret)
 {
     if (s == NULL) {
         return -1;
 
     } else if (strcasecmp(s, "true") == 0
                || strcasecmp(s, "on") == 0
                || strcasecmp(s, "yes") == 0 || strcasecmp(s, "y") == 0 || strcasecmp(s, "1") == 0) {
         *ret = TRUE;
         return 1;
 
     } else if (strcasecmp(s, "false") == 0
                || strcasecmp(s, "off") == 0
                || strcasecmp(s, "no") == 0 || strcasecmp(s, "n") == 0 || strcasecmp(s, "0") == 0) {
         *ret = FALSE;
         return 1;
     }
     return -1;
 }
 
 char *
 crm_strip_trailing_newline(char *str)
 {
     int len;
 
     if (str == NULL) {
         return str;
     }
 
     for (len = strlen(str) - 1; len >= 0 && str[len] == '\n'; len--) {
         str[len] = '\0';
     }
 
     return str;
 }
 
 gboolean
 crm_str_eq(const char *a, const char *b, gboolean use_case)
 {
     if (use_case) {
         return g_strcmp0(a, b) == 0;
 
         /* TODO - Figure out which calls, if any, really need to be case independent */
     } else if (a == b) {
         return TRUE;
 
     } else if (a == NULL || b == NULL) {
         /* shouldn't be comparing NULLs */
         return FALSE;
 
     } else if (strcasecmp(a, b) == 0) {
         return TRUE;
     }
     return FALSE;
 }
 
 /*!
  * \brief Check whether a string starts with a certain sequence
  *
  * \param[in] str    String to check
  * \param[in] prefix Sequence to match against beginning of \p str
  *
  * \return \c true if \p str begins with match, \c false otherwise
  * \note This is equivalent to !strncmp(s, prefix, strlen(prefix))
  *       but is likely less efficient when prefix is a string literal
  *       if the compiler optimizes away the strlen() at compile time,
  *       and more efficient otherwise.
  */
 bool
 pcmk__starts_with(const char *str, const char *prefix)
 {
     const char *s = str;
     const char *p = prefix;
 
     if (!s || !p) {
         return false;
     }
     while (*s && *p) {
         if (*s++ != *p++) {
             return false;
         }
     }
     return (*p == 0);
 }
 
 static inline bool
 ends_with(const char *s, const char *match, bool as_extension)
 {
     if (pcmk__str_empty(match)) {
         return true;
     } else if (s == NULL) {
         return false;
     } else {
         size_t slen, mlen;
 
         /* Besides as_extension, we could also check
            !strchr(&match[1], match[0]) but that would be inefficient.
          */
         if (as_extension) {
             s = strrchr(s, match[0]);
             return (s == NULL)? false : !strcmp(s, match);
         }
 
         mlen = strlen(match);
         slen = strlen(s);
         return ((slen >= mlen) && !strcmp(s + slen - mlen, match));
     }
 }
 
 /*!
  * \internal
  * \brief Check whether a string ends with a certain sequence
  *
  * \param[in] s      String to check
  * \param[in] match  Sequence to match against end of \p s
  *
  * \return \c true if \p s ends case-sensitively with match, \c false otherwise
  * \note pcmk__ends_with_ext() can be used if the first character of match
  *       does not recur in match.
  */
 bool
 pcmk__ends_with(const char *s, const char *match)
 {
     return ends_with(s, match, false);
 }
 
 /*!
  * \internal
  * \brief Check whether a string ends with a certain "extension"
  *
  * \param[in] s      String to check
  * \param[in] match  Extension to match against end of \p s, that is,
  *                   its first character must not occur anywhere
  *                   in the rest of that very sequence (example: file
  *                   extension where the last dot is its delimiter,
  *                   e.g., ".html"); incorrect results may be
  *                   returned otherwise.
  *
  * \return \c true if \p s ends (verbatim, i.e., case sensitively)
  *         with "extension" designated as \p match (including empty
  *         string), \c false otherwise
  *
  * \note Main incentive to prefer this function over \c pcmk__ends_with()
  *       where possible is the efficiency (at the cost of added
  *       restriction on \p match as stated; the complexity class
  *       remains the same, though: BigO(M+N) vs. BigO(M+2N)).
  */
 bool
 pcmk__ends_with_ext(const char *s, const char *match)
 {
     return ends_with(s, match, true);
 }
 
 /*
  * This re-implements g_str_hash as it was prior to glib2-2.28:
  *
  * https://gitlab.gnome.org/GNOME/glib/commit/354d655ba8a54b754cb5a3efb42767327775696c
  *
  * Note that the new g_str_hash is presumably a *better* hash (it's actually
  * a correct implementation of DJB's hash), but we need to preserve existing
  * behaviour, because the hash key ultimately determines the "sort" order
  * when iterating through GHashTables, which affects allocation of scores to
  * clone instances when iterating through rsc->allowed_nodes.  It (somehow)
  * also appears to have some minor impact on the ordering of a few
  * pseudo_event IDs in the transition graph.
  */
 guint
 g_str_hash_traditional(gconstpointer v)
 {
     const signed char *p;
     guint32 h = 0;
 
     for (p = v; *p != '\0'; p++)
         h = (h << 5) - h + *p;
 
     return h;
 }
 
 /* used with hash tables where case does not matter */
 gboolean
 crm_strcase_equal(gconstpointer a, gconstpointer b)
 {
     return crm_str_eq((const char *) a, (const char *) b, FALSE);
 }
 
 guint
 crm_strcase_hash(gconstpointer v)
 {
     const signed char *p;
     guint32 h = 0;
 
     for (p = v; *p != '\0'; p++)
         h = (h << 5) - h + g_ascii_tolower(*p);
 
     return h;
 }
 
 static void
 copy_str_table_entry(gpointer key, gpointer value, gpointer user_data)
 {
     if (key && value && user_data) {
         g_hash_table_insert((GHashTable*)user_data, strdup(key), strdup(value));
     }
 }
 
 GHashTable *
 crm_str_table_dup(GHashTable *old_table)
 {
     GHashTable *new_table = NULL;
 
     if (old_table) {
         new_table = crm_str_table_new();
         g_hash_table_foreach(old_table, copy_str_table_entry, new_table);
     }
     return new_table;
 }
 
 /*!
  * \internal
  * \brief Add a word to a space-separated string list
  *
  * \param[in,out] list  Pointer to beginning of list
  * \param[in]     word  Word to add to list
  *
  * \return (Potentially new) beginning of list
  * \note This dynamically reallocates list as needed.
  */
 char *
 pcmk__add_word(char *list, const char *word)
 {
     if (word != NULL) {
         size_t len = list? strlen(list) : 0;
 
         list = realloc_safe(list, len + strlen(word) + 2); // 2 = space + EOS
         sprintf(list + len, " %s", word);
     }
     return list;
 }
 
 /*!
  * \internal
  * \brief Compress data
  *
  * \param[in]  data        Data to compress
  * \param[in]  length      Number of characters of data to compress
  * \param[in]  max         Maximum size of compressed data (or 0 to estimate)
  * \param[out] result      Where to store newly allocated compressed result
  * \param[out] result_len  Where to store actual compressed length of result
  *
  * \return Standard Pacemaker return code
  */
 int
 pcmk__compress(const char *data, unsigned int length, unsigned int max,
                char **result, unsigned int *result_len)
 {
     int rc;
     char *compressed = NULL;
     char *uncompressed = strdup(data);
 #ifdef CLOCK_MONOTONIC
     struct timespec after_t;
     struct timespec before_t;
 #endif
 
     if (max == 0) {
         max = (length * 1.01) + 601; // Size guaranteed to hold result
     }
 
 #ifdef CLOCK_MONOTONIC
     clock_gettime(CLOCK_MONOTONIC, &before_t);
 #endif
 
     compressed = calloc((size_t) max, sizeof(char));
     CRM_ASSERT(compressed);
 
     *result_len = max;
     rc = BZ2_bzBuffToBuffCompress(compressed, result_len, uncompressed, length,
                                   CRM_BZ2_BLOCKS, 0, CRM_BZ2_WORK);
     free(uncompressed);
     if (rc != BZ_OK) {
         crm_err("Compression of %d bytes failed: %s " CRM_XS " bzerror=%d",
                 length, bz2_strerror(rc), rc);
         free(compressed);
         return pcmk_rc_error;
     }
 
 #ifdef CLOCK_MONOTONIC
     clock_gettime(CLOCK_MONOTONIC, &after_t);
 
     crm_trace("Compressed %d bytes into %d (ratio %d:1) in %.0fms",
              length, *result_len, length / (*result_len),
              (after_t.tv_sec - before_t.tv_sec) * 1000 +
              (after_t.tv_nsec - before_t.tv_nsec) / 1e6);
 #else
     crm_trace("Compressed %d bytes into %d (ratio %d:1)",
              length, *result_len, length / (*result_len));
 #endif
 
     *result = compressed;
     return pcmk_rc_ok;
 }
 
 char *
 crm_strdup_printf(char const *format, ...)
 {
     va_list ap;
     int len = 0;
     char *string = NULL;
 
     va_start(ap, format);
     len = vasprintf (&string, format, ap);
     CRM_ASSERT(len > 0);
     va_end(ap);
     return string;
 }
 
 int
 pcmk__parse_ll_range(const char *srcstring, long long *start, long long *end)
 {
     char *remainder = NULL;
 
     CRM_ASSERT(start != NULL && end != NULL);
 
     *start = -1;
     *end = -1;
 
     crm_trace("Attempting to decode: [%s]", srcstring);
     if (srcstring == NULL || strcmp(srcstring, "") == 0 || strcmp(srcstring, "-") == 0) {
         return pcmk_rc_unknown_format;
     }
 
     /* String starts with a dash, so this is either a range with
      * no beginning or garbage.
      * */
     if (*srcstring == '-') {
         int rc = scan_ll(srcstring+1, end, &remainder);
 
         if (rc != pcmk_rc_ok || *remainder != '\0') {
             return pcmk_rc_unknown_format;
         } else {
             return pcmk_rc_ok;
         }
     }
 
     if (scan_ll(srcstring, start, &remainder) != pcmk_rc_ok) {
         return pcmk_rc_unknown_format;
     }
 
     if (*remainder && *remainder == '-') {
         if (*(remainder+1)) {
             char *more_remainder = NULL;
             int rc = scan_ll(remainder+1, end, &more_remainder);
 
             if (rc != pcmk_rc_ok || *more_remainder != '\0') {
                 return pcmk_rc_unknown_format;
             }
         }
     } else if (*remainder && *remainder != '-') {
         *start = -1;
         return pcmk_rc_unknown_format;
     } else {
         /* The input string contained only one number.  Set start and end
          * to the same value and return pcmk_rc_ok.  This gives the caller
          * a way to tell this condition apart from a range with no end.
          */
         *end = *start;
     }
 
     return pcmk_rc_ok;
 }
 
 gboolean
 pcmk__str_in_list(GList *lst, const gchar *s)
 {
     if (lst == NULL) {
         return FALSE;
     }
 
     if (strcmp(lst->data, "*") == 0 && lst->next == NULL) {
         return TRUE;
     }
 
     return g_list_find_custom(lst, s, (GCompareFunc) strcmp) != NULL;
 }
 
 bool
 pcmk__str_any_of(const char *s, ...)
 {
     bool rc = false;
     va_list ap;
 
     va_start(ap, s);
 
     while (1) {
         const char *ele = va_arg(ap, const char *);
 
         if (ele == NULL) {
             break;
         } else if (crm_str_eq(s, ele, FALSE)) {
             rc = true;
             break;
         }
     }
 
     va_end(ap);
     return rc;
 }
 
 /*
  * \brief Sort strings, with numeric portions sorted numerically
  *
  * Sort two strings case-insensitively like strcasecmp(), but with any numeric
  * portions of the string sorted numerically. This is particularly useful for
  * node names (for example, "node10" will sort higher than "node9" but lower
  * than "remotenode9").
  *
  * \param[in] s1  First string to compare (must not be NULL)
  * \param[in] s2  Second string to compare (must not be NULL)
  *
  * \retval -1 \p s1 comes before \p s2
  * \retval  0 \p s1 and \p s2 are equal
  * \retval  1 \p s1 comes after \p s2
  */
 int
 pcmk_numeric_strcasecmp(const char *s1, const char *s2)
 {
     while (*s1 && *s2) {
         if (isdigit(*s1) && isdigit(*s2)) {
             // If node names contain a number, sort numerically
 
             char *end1 = NULL;
             char *end2 = NULL;
             long num1 = strtol(s1, &end1, 10);
             long num2 = strtol(s2, &end2, 10);
 
             // allow ordering e.g. 007 > 7
             size_t len1 = end1 - s1;
             size_t len2 = end2 - s2;
 
             if (num1 < num2) {
                 return -1;
             } else if (num1 > num2) {
                 return 1;
             } else if (len1 < len2) {
                 return -1;
             } else if (len1 > len2) {
                 return 1;
             }
             s1 = end1;
             s2 = end2;
         } else {
             // Compare non-digits case-insensitively
             int lower1 = tolower(*s1);
             int lower2 = tolower(*s2);
 
             if (lower1 < lower2) {
                 return -1;
             } else if (lower1 > lower2) {
                 return 1;
             }
             ++s1;
             ++s2;
         }
     }
     if (!*s1 && *s2) {
         return -1;
     } else if (*s1 && !*s2) {
         return 1;
     }
     return 0;
 }
+
+/*
+ * \brief Sort strings.
+ *
+ * This is your one-stop function for string comparison.  By default, this
+ * function works like g_strcmp0.  That is, like strcmp but a NULL string
+ * sorts before a non-NULL string.
+ *
+ * Behavior can be changed with various flags:
+ *
+ * - pcmk__str_regex - The second string is a regular expression that the
+ *                     first string will be matched against.
+ * - pcmk__str_casei - By default, comparisons are done taking case into
+ *                     account.  This flag makes comparisons case-insensitive.
+ *                     This can be combined with pcmk__str_regex.
+ * - pcmk__str_null_matches - If one string is NULL and the other is not,
+ *                            still return 0.
+ *
+ * \param[in] s1    First string to compare
+ * \param[in] s2    Second string to compare, or a regular expression to
+ *                  match if pcmk__str_regex is set
+ * \param[in] flags A bitfield of pcmk__str_flags to modify operation
+ *
+ * \retval -1 \p s1 is NULL or comes before \p s2
+ * \retval  0 \p s1 and \p s2 are equal, or \p s1 is found in \p s2 if
+ *            pcmk__str_regex is set
+ * \retval  1 \p s2 is NULL or \p s1 comes after \p s2, or if \p s2
+ *            is an invalid regular expression, or \p s1 was not found
+ *            in \p s2 if pcmk__str_regex is set.
+ */
+int
+pcmk__strcmp(const char *s1, const char *s2, uint32_t flags)
+{
+    /* If this flag is set, the second string is a regex. */
+    if (is_set(flags, pcmk__str_regex)) {
+        regex_t *r_patt = calloc(1, sizeof(regex_t));
+        int reg_flags = REG_EXTENDED | REG_NOSUB | (is_set(flags, pcmk__str_casei) ? REG_ICASE : 0);
+        int regcomp_rc = 0;
+        int rc = 0;
+
+        if (s1 == NULL || s2 == NULL) {
+            free(r_patt);
+            return 1;
+        }
+
+        regcomp_rc = regcomp(r_patt, s2, reg_flags);
+        if (regcomp_rc != 0) {
+            rc = 1;
+            crm_err("Bad regex '%s' for update: %s", s2, strerror(regcomp_rc));
+        } else {
+            rc = regexec(r_patt, s1, 0, NULL, 0);
+
+            if (rc != 0) {
+                rc = 1;
+            }
+        }
+
+        regfree(r_patt);
+        free(r_patt);
+        return rc;
+    }
+
+    /* If the strings are the same pointer, return 0 immediately. */
+    if (s1 == s2) {
+        return 0;
+    }
+
+    /* If this flag is set, return 0 if either (or both) of the input strings
+     * are NULL.  If neither one is NULL, we need to continue and compare
+     * them normally.
+     */
+    if (is_set(flags, pcmk__str_null_matches)) {
+        if (s1 == NULL || s2 == NULL) {
+            return 0;
+        }
+    }
+
+    /* Handle the cases where one is NULL and the str_null_matches flag is not set.
+     * A NULL string always sorts to the beginning.
+     */
+    if (s1 == NULL) {
+        return -1;
+    } else if (s2 == NULL) {
+        return 1;
+    }
+
+    if (is_set(flags, pcmk__str_casei)) {
+        return strcasecmp(s1, s2);
+    } else {
+        return strcmp(s1, s2);
+    }
+}
diff --git a/lib/common/tests/strings/Makefile.am b/lib/common/tests/strings/Makefile.am
index 859559f1f3..11c3bd3c00 100644
--- a/lib/common/tests/strings/Makefile.am
+++ b/lib/common/tests/strings/Makefile.am
@@ -1,20 +1,21 @@
 AM_CPPFLAGS = -I$(top_srcdir)/include -I$(top_builddir)/include
 LDADD = $(top_builddir)/lib/common/libcrmcommon.la
 
 include $(top_srcdir)/mk/glib-tap.mk
 
 # Add each test program here.  Each test should be written as a little standalone
 # program using the glib unit testing functions.  See the documentation for more
 # information.
 #
 # https://developer.gnome.org/glib/unstable/glib-Testing.html
 test_programs = pcmk__parse_ll_range \
-				pcmk__str_any_of
+				pcmk__str_any_of \
+				pcmk__strcmp
 
 # If any extra data needs to be added to the source distribution, add it to the
 # following list.
 dist_test_data =
 
 # If any extra data needs to be used by tests but should not be added to the
 # source distribution, add it to the following list.
 test_data =
diff --git a/lib/common/tests/strings/pcmk__strcmp.c b/lib/common/tests/strings/pcmk__strcmp.c
new file mode 100644
index 0000000000..296b1a7952
--- /dev/null
+++ b/lib/common/tests/strings/pcmk__strcmp.c
@@ -0,0 +1,76 @@
+#include <glib.h>
+
+#include <crm_internal.h>
+
+static void
+same_pointer(void) {
+    const char *s1 = "abcd";
+    const char *s2 = "wxyz";
+
+    g_assert_cmpint(pcmk__strcmp(s1, s1, pcmk__str_none), ==, 0);
+    g_assert_true(pcmk__str_eq(s1, s1, pcmk__str_none));
+    g_assert_cmpint(pcmk__strcmp(s1, s2, pcmk__str_none), !=, 0);
+    g_assert_false(pcmk__str_eq(s1, s2, pcmk__str_none));
+    g_assert_cmpint(pcmk__strcmp(NULL, NULL, pcmk__str_none), ==, 0);
+}
+
+static void
+one_is_null(void) {
+    const char *s1 = "abcd";
+
+    g_assert_cmpint(pcmk__strcmp(s1, NULL, pcmk__str_null_matches), ==, 0);
+    g_assert_true(pcmk__str_eq(s1, NULL, pcmk__str_null_matches));
+    g_assert_cmpint(pcmk__strcmp(NULL, s1, pcmk__str_null_matches), ==, 0);
+    g_assert_cmpint(pcmk__strcmp(s1, NULL, pcmk__str_none), >, 0);
+    g_assert_false(pcmk__str_eq(s1, NULL, pcmk__str_none));
+    g_assert_cmpint(pcmk__strcmp(NULL, s1, pcmk__str_none), <, 0);
+}
+
+static void
+case_matters(void) {
+    const char *s1 = "abcd";
+    const char *s2 = "ABCD";
+
+    g_assert_cmpint(pcmk__strcmp(s1, s2, pcmk__str_none), >, 0);
+    g_assert_false(pcmk__str_eq(s1, s2, pcmk__str_none));
+    g_assert_cmpint(pcmk__strcmp(s2, s1, pcmk__str_none), <, 0);
+}
+
+static void
+case_insensitive(void) {
+    const char *s1 = "abcd";
+    const char *s2 = "ABCD";
+
+    g_assert_cmpint(pcmk__strcmp(s1, s2, pcmk__str_casei), ==, 0);
+    g_assert_true(pcmk__str_eq(s1, s2, pcmk__str_casei));
+}
+
+static void
+regex(void) {
+    const char *s1 = "abcd";
+    const char *s2 = "ABCD";
+
+    g_assert_cmpint(pcmk__strcmp(NULL, "a..d", pcmk__str_regex), ==, 1);
+    g_assert_cmpint(pcmk__strcmp(s1, NULL, pcmk__str_regex), ==, 1);
+    g_assert_cmpint(pcmk__strcmp(s1, "a..d", pcmk__str_regex), ==, 0);
+    g_assert_true(pcmk__str_eq(s1, "a..d", pcmk__str_regex));
+    g_assert_cmpint(pcmk__strcmp(s1, "xxyy", pcmk__str_regex), !=, 0);
+    g_assert_false(pcmk__str_eq(s1, "xxyy", pcmk__str_regex));
+    g_assert_cmpint(pcmk__strcmp(s2, "a..d", pcmk__str_regex|pcmk__str_casei), ==, 0);
+    g_assert_true(pcmk__str_eq(s2, "a..d", pcmk__str_regex|pcmk__str_casei));
+    g_assert_cmpint(pcmk__strcmp(s2, "a..d", pcmk__str_regex), !=, 0);
+    g_assert_false(pcmk__str_eq(s2, "a..d", pcmk__str_regex));
+    g_assert_cmpint(pcmk__strcmp(s2, "*ab", pcmk__str_regex), ==, 1);
+}
+
+int main(int argc, char **argv) {
+    g_test_init(&argc, &argv, NULL);
+
+    g_test_add_func("/common/strings/strcmp/same_pointer", same_pointer);
+    g_test_add_func("/common/strings/strcmp/one_is_null", one_is_null);
+    g_test_add_func("/common/strings/strcmp/case_matters", case_matters);
+    g_test_add_func("/common/strings/strcmp/case_insensitive", case_insensitive);
+    g_test_add_func("/common/strings/strcmp/regex", regex);
+
+    return g_test_run();
+}