1 files changed, 109 insertions, 0 deletions
diff --git a/src/util/extpar.c b/src/util/extpar.c
new file mode 100644
index 0000000..0b106ba
--- /dev/null
+++ b/src/util/extpar.c
@@ -0,0 +1,109 @@
+/*++
+/* NAME
+/*	extpar 3
+/* SUMMARY
+/*	extract text from parentheses
+/* SYNOPSIS
+/*	#include <stringops.h>
+/*
+/*	char	*extpar(bp, parens, flags)
+/*	char	**bp;
+/*	const char *parens;
+/*	int	flags;
+/* DESCRIPTION
+/*	extpar() extracts text from an input string that is enclosed
+/*	in the specified parentheses, and updates the buffer pointer
+/*	to point to that text.
+/*
+/*	Arguments:
+/* .IP bp
+/*	Pointer to buffer pointer. Both the buffer and the buffer
+/*	pointer are modified.
+/* .IP parens
+/*	One matching pair of parentheses, opening parenthesis first.
+/* .IP flags
+/*	EXTPAR_FLAG_NONE, or the bitwise OR of one or more flags:
+/* .RS
+/* .IP EXTPAR_FLAG_EXTRACT
+/*	This flag is intended to instruct extpar() callers that
+/*	extpar() should be invoked. It has no effect on expar()
+/*	itself.
+/* .IP EXTPAR_FLAG_STRIP
+/*	Skip whitespace after the opening parenthesis, and trim
+/*	whitespace before the closing parenthesis.
+/* .RE
+/* DIAGNOSTICS
+/*	In case of error the result value is a dynamically-allocated
+/*	string with a description of the problem that includes a
+/*	copy of the offending input.  A non-null result value should
+/*	be destroyed with myfree(). The following describes the errors
+/*	and the state of the buffer and buffer pointer.
+/* .IP "no opening parenthesis at start of text"
+/*	The buffer pointer points to the input text.
+/* .IP "missing closing parenthesis"
+/*	The buffer pointer points to text as if a closing parenthesis
+/*	were present at the end of the input.
+/* .IP "text after closing parenthesis"
+/*	The buffer pointer points to text as if the offending text
+/*	were not present.
+/* SEE ALSO
+/*	balpar(3) determine length of string in parentheses
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/*	Wietse Venema
+/*	IBM T.J. Watson Research
+/*	P.O. Box 704
+/*	Yorktown Heights, NY 10598, USA
+/*
+/*	Wietse Venema
+/*	Google, Inc.
+/*	111 8th Avenue
+/*	New York, NY 10011, USA
+/*--*/
+
+ /*
+  * System library.
+  */
+#include <sys_defs.h>
+#include <ctype.h>
+
+ /*
+  * Utility library.
+  */
+#include <vstring.h>
+#include <stringops.h>
+
+/* extpar - extract text from parentheses */
+
+char   *extpar(char **bp, const char *parens, int flags)
+{
+    char   *cp = *bp;
+    char   *err = 0;
+    size_t  len;
+
+    if (cp[0] != parens[0]) {
+	err = vstring_export(vstring_sprintf(vstring_alloc(100),
+		      "no '%c' at start of text in \"%s\"", parens[0], cp));
+	len = 0;
+    } else if ((len = balpar(cp, parens)) == 0) {
+	err = concatenate("missing '", parens + 1, "' in \"",
+			  cp, "\"", (char *) 0);
+	cp += 1;
+    } else {
+	if (cp[len] != 0)
+	    err = concatenate("syntax error after '", parens + 1, "' in \"",
+			      cp, "\"", (char *) 0);
+	cp += 1;
+	cp[len -= 2] = 0;
+    }
+    if (flags & EXTPAR_FLAG_STRIP) {
+	trimblanks(cp, len)[0] = 0;
+	while (ISSPACE(*cp))
+	    cp++;
+    }
+    *bp = cp;
+    return (err);
+}