From c7f62eca710243f04759a1bf99f39a5f166a8886 Mon Sep 17 00:00:00 2001
From: Martin Mares <mj@ucw.cz>
Date: Sun, 12 Aug 2012 22:51:33 +0200
Subject: [PATCH] mparse: Allow to choose the header fields to print

---
 mparse.c | 41 ++++++++++++++++++++++++++++++++---------
 1 file changed, 32 insertions(+), 9 deletions(-)

diff --git a/mparse.c b/mparse.c
index 9c31851..962755e 100644
--- a/mparse.c
+++ b/mparse.c
@@ -18,7 +18,7 @@ const char progname[] = "mparse";
 static char buf[BUFSIZE];
 static char *bpos=buf, *bend=buf;
 
-static char *getline(void)
+static char *get_line(void)
 {
   if (!bpos)
     return NULL;
@@ -63,6 +63,21 @@ static char *getline(void)
     }
 }
 
+static int want_header(char *line, char **want, int n_want)
+{
+  if (!n_want)
+    return 1;
+
+  for (int i=0; i<n_want; i++)
+    {
+      int len = strlen(want[i]);
+      if (!strncasecmp(line, want[i], len))
+	return 1;
+    }
+
+  return 0;
+}
+
 enum state {
   S_INITIAL,
   S_HEADER,
@@ -70,12 +85,13 @@ enum state {
 };
 
 int
-main(int argc UNUSED, char **argv UNUSED)
+main(int argc, char **argv)
 {
   char *c;
   enum state state = S_INITIAL;
+  int want = 0;
 
-  while (c = getline())
+  while (c = get_line())
     {
       // printf("<%s>\n", c);
       if (state == S_INITIAL || state == S_BODY)
@@ -95,15 +111,22 @@ main(int argc UNUSED, char **argv UNUSED)
 	    }
 	  else if (*c == ' ' || *c == '\t')
 	    {
-	      while (*c == ' ' || *c == '\t')
-		c++;
-	      putchar(' ');
-	      fputs(c, stdout);
+	      if (want)
+		{
+		  while (*c == ' ' || *c == '\t')
+		    c++;
+		  putchar(' ');
+		  fputs(c, stdout);
+		}
 	    }
 	  else
 	    {
-	      putchar('\n');
-	      fputs(c, stdout);
+	      want = want_header(c, argv+1, argc-1);
+	      if (want)
+		{
+		  putchar('\n');
+		  fputs(c, stdout);
+		}
 	    }
 	}
     }
-- 
2.39.2