1 files changed, 122 insertions, 0 deletions
diff --git a/src/util/line_wrap.c b/src/util/line_wrap.c
new file mode 100644
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--- /dev/null
+++ b/src/util/line_wrap.c
@@ -0,0 +1,122 @@
+/*++
+/* NAME
+/*	line_wrap 3
+/* SUMMARY
+/*	wrap long lines upon output
+/* SYNOPSIS
+/*	#include <line_wrap.h>
+/*
+/*	void	line_wrap(string, len, indent, output_fn, context)
+/*	const char *buf;
+/*	int	len;
+/*	int	indent;
+/*	void	(*output_fn)(const char *str, int len, int indent, void *context);
+/*	void	*context;
+/* DESCRIPTION
+/*	The \fBline_wrap\fR routine outputs the specified string via
+/*	the specified output function, and attempts to keep output lines
+/*	shorter than the specified length. The routine does not attempt to
+/*	break long words that do not fit on a single line. Upon output,
+/*	trailing whitespace is stripped.
+/*
+/*	Arguments
+/* .IP string
+/*	The input, which cannot contain any newline characters.
+/* .IP len
+/*	The desired maximal output line length.
+/* .IP indent
+/*	The desired amount of indentation of the second etc. output lines
+/*	with respect to the first output line. A negative indent causes
+/*	only the first line to be indented; a positive indent causes all
+/*	but the first line to be indented. A zero count causes no indentation.
+/* .IP output_fn
+/*	The output function that is called with as arguments a string
+/*	pointer, a string length, a non-negative indentation count, and
+/*	application context. A typical implementation looks like this:
+/* .sp
+/* .nf
+/* .na
+void print(const char *str, int len, int indent, void *context)
+{
+    VSTREAM *fp = (VSTREAM *) context;
+
+    vstream_fprintf(fp, "%*s%.*s", indent, "", len, str);
+}
+/* .fi
+/* .ad
+/* .IP context
+/*	Application context that is passed on to the output function.
+/*	For example, a VSTREAM pointer, or a structure that contains
+/*	a VSTREAM pointer.
+/* BUGS
+/*	No tab expansion and no backspace processing.
+/* 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
+/*--*/
+
+/* System library. */
+
+#include <sys_defs.h>
+#include <string.h>
+#include <ctype.h>
+
+/* Utility library. */
+
+#include <line_wrap.h>
+
+/* line_wrap - wrap long lines upon output */
+
+void    line_wrap(const char *str, int len, int indent, LINE_WRAP_FN output_fn,
+		          void *context)
+{
+    const char *start_line;
+    const char *word;
+    const char *next_word;
+    const char *next_space;
+    int     line_len;
+    int     curr_len;
+    int     curr_indent;
+
+    if (indent < 0) {
+	curr_indent = -indent;
+	curr_len = len + indent;
+    } else {
+	curr_indent = 0;
+	curr_len = len;
+    }
+
+    /*
+     * At strategic positions, output what we have seen, after stripping off
+     * trailing blanks.
+     */
+    for (start_line = word = str; word != 0; word = next_word) {
+	next_space = word + strcspn(word, " \t");
+	if (word > start_line) {
+	    if (next_space - start_line > curr_len) {
+		line_len = word - start_line;
+		while (line_len > 0 && ISSPACE(start_line[line_len - 1]))
+		    line_len--;
+		output_fn(start_line, line_len, curr_indent, context);
+		while (*word && ISSPACE(*word))
+		    word++;
+		if (start_line == str) {
+		    curr_indent += indent;
+		    curr_len -= indent;
+		}
+		start_line = word;
+	    }
+	}
+	next_word = *next_space ? next_space + 1 : 0;
+    }
+    line_len = strlen(start_line);
+    while (line_len > 0 && ISSPACE(start_line[line_len - 1]))
+	line_len--;
+    output_fn(start_line, line_len, curr_indent, context);
+}