Add a "fork" of musl as //fusl.

fusl/src/misc/fmtmsg.c

+/* Public domain fmtmsg()
+ * Written by Isaac Dunham, 2014
+ */
+#include <fmtmsg.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <pthread.h>
+
+/*
+ * If lstr is the first part of bstr, check that the next char in bstr
+ * is either \0 or :
+ */
+static int _strcolcmp(const char *lstr, const char *bstr)
+{
+        size_t i = 0;
+        while (lstr[i] && bstr[i] && (bstr[i] == lstr[i])) i++;
+        if ( lstr[i] || (bstr[i] && bstr[i] != ':')) return 1;
+        return 0;
+}
+
+int fmtmsg(long classification, const char *label, int severity,
+           const char *text, const char *action, const char *tag)
+{
+        int ret = 0, i, consolefd, verb = 0;
+        char *errstring = MM_NULLSEV, *cmsg = getenv("MSGVERB");
+        char *const msgs[] = {
+                "label", "severity", "text", "action", "tag", NULL
+        };
+        int cs;
+
+        pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
+
+        if (severity == MM_HALT) errstring = "HALT: ";
+        else if (severity == MM_ERROR) errstring = "ERROR: ";
+        else if (severity == MM_WARNING) errstring = "WARNING: ";
+        else if (severity == MM_INFO) errstring = "INFO: ";
+
+        if (classification & MM_CONSOLE) {
+                consolefd = open("/dev/console", O_WRONLY);
+                if (consolefd < 0) {
+                        ret = MM_NOCON;
+                } else {
+                        if (dprintf(consolefd, "%s%s%s%s%s%s%s%s\n",
+                                    label?label:"", label?": ":"",
+                                    severity?errstring:"", text?text:"",
+                                    action?"\nTO FIX: ":"",
+                                    action?action:"", action?" ":"",
+                                    tag?tag:"" )<1)
+                                ret = MM_NOCON;
+                        close(consolefd);
+                }
+        }
+
+        if (classification & MM_PRINT) {
+                while (cmsg && cmsg[0]) {
+                        for(i=0; msgs[i]; i++) {
+                                if (!_strcolcmp(msgs[i], cmsg)) break;
+                        }
+                        if (msgs[i] == NULL) {
+                                //ignore MSGVERB-unrecognized component
+                                verb = 0xFF;
+                                break;
+                        } else {
+                                verb |= (1 << i);
+                                cmsg = strchr(cmsg, ':');
+                                if (cmsg) cmsg++;
+                        }
+                }
+                if (!verb) verb = 0xFF;
+                if (dprintf(2, "%s%s%s%s%s%s%s%s\n",
+                            (verb&1 && label) ? label : "",
+                            (verb&1 && label) ? ": " : "",
+                            (verb&2 && severity) ? errstring : "",
+                            (verb&4 && text) ? text : "",
+                            (verb&8 && action) ? "\nTO FIX: " : "",
+                            (verb&8 && action) ? action : "",
+                            (verb&8 && action) ? " " : "",
+                            (verb&16 && tag) ? tag : "" ) < 1)
+                        ret |= MM_NOMSG;
+        }
+        if ((ret & (MM_NOCON|MM_NOMSG)) == (MM_NOCON|MM_NOMSG))
+                ret = MM_NOTOK;
+
+        pthread_setcancelstate(cs, 0);
+
+        return ret;
+}