Made code async-signal-safe

snprinterr.c

@@ -0,0 +1,85 @@
+/* snprinterr.c */
+/* Copyright Gerhard Rieger */
+
+/* a function similar to vsnprintf() but it just handles %m */
+
+#include "config.h"
+
+#include <stddef.h>	/* ptrdiff_t */
+#include <ctype.h>	/* isdigit() */
+#include <stdarg.h>
+#include <stdlib.h>
+#include <errno.h>
+#if HAVE_SYSLOG_H
+#include <syslog.h>
+#endif
+#include <sys/utsname.h>
+#include <time.h>	/* time_t, strftime() */
+#include <sys/time.h>	/* gettimeofday() */
+#include <stdio.h>
+#include <string.h>
+#if HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#include "snprinterr.h"
+
+#define HAVE_STRERROR_R 0
+/* replace %m in format with actual strerror() message, write result to *str.
+   keep other % formats unchanged!
+   writes at most size chars including the terminating \0 to *str
+   returns the number of bytes in the output without terminating \0
+   result is always \0 terminated except when size==0
+ */
+int snprinterr(char *str, size_t size, const char *format) {
+   char c;
+   int full = 0;	/* 1 means: there is no space left in * str for more data or \0 */
+   int count = 0;
+   if (size == 0)  return 0;
+   if (count >= size)  full = 1;
+   while (c = *format++) {
+      if (c == '%') {
+	 c = *format++;
+	 switch (c) {
+	 case '\0':
+	    ++count; if (!full) { (*str++ = '%'); if (count+1 >= size) full = 1; }
+	    break;
+	 default:
+	    ++count; if (!full) { (*str++ = '%'); if (count+1 >= size) full = 1; }
+	    ++count; if (!full) { (*str++ = c);   if (count+1 >= size) full = 1; }
+	    break;
+	 case 'm':
+	    {
+#if HAVE_STRERROR_R
+#              define BUFLEN 64
+	       char buf[BUFLEN] = "";
+#endif /* HAVE_STRERROR_R */
+	       char *bufp;
+#if !HAVE_STRERROR_R
+	       bufp = strerror(errno);
+#else
+	       /* there are two versions floating around... */
+#  if 1	/* GNU version */
+	       bufp = strerror_r(errno, buf, BUFLEN);
+#  else	/* standard version */
+	       strerror_r(errno, buf, BUFLEN);
+	       bufp = buf;
+#  endif
+#endif /* HAVE_STRERROR_R */
+	       while ((c = *bufp++) != '\0') {
+		  ++count; if (!full) { (*str++ = c);   if (count+1 >= size) full = 1; }
+	       }
+	    }
+	    c = ' ';	/* not \0 ! */
+	    break;
+	 }
+	 if (c == '\0')  break;
+      } else {
+	 ++count; if (!full) { (*str++ = c); if (count+1 >= size)  full = 1; }
+      }
+   }
+   *str++ = '\0';	/* always write terminating \0 */
+   return count;
+#undef BUFLEN
+}
+