Convert tests to use "modify add_file" and remove standalone program.
diff --git a/regress/CMakeLists.txt b/regress/CMakeLists.txt
index cb5873c..a22e2d4 100644
--- a/regress/CMakeLists.txt
+++ b/regress/CMakeLists.txt
@@ -2,7 +2,6 @@
 
 SET(STANDALONE_TEST_PROGRAMS
   add_from_buffer
-  add_from_file
   add_from_filep
   add_from_zip
   encrypt
diff --git a/regress/Makefile.am b/regress/Makefile.am
index 61f2147..0243c59 100644
--- a/regress/Makefile.am
+++ b/regress/Makefile.am
@@ -1,6 +1,5 @@
 noinst_PROGRAMS= \
 	add_from_buffer \
-	add_from_file \
 	add_from_filep \
 	add_from_zip \
 	encrypt \
diff --git a/regress/add_from_file.c b/regress/add_from_file.c
deleted file mode 100644
index d4decbd..0000000
--- a/regress/add_from_file.c
+++ /dev/null
@@ -1,101 +0,0 @@
-/*
-  add_from_file.c -- test case for adding file to archive
-  Copyright (C) 1999, 2003, 2005 Dieter Baron and Thomas Klausner
-
-  This file is part of libzip, a library to manipulate ZIP archives.
-  The authors can be contacted at <libzip@nih.at>
-
-  Redistribution and use in source and binary forms, with or without
-  modification, are permitted provided that the following conditions
-  are met:
-  1. Redistributions of source code must retain the above copyright
-     notice, this list of conditions and the following disclaimer.
-  2. Redistributions in binary form must reproduce the above copyright
-     notice, this list of conditions and the following disclaimer in
-     the documentation and/or other materials provided with the
-     distribution.
-  3. The names of the authors may not be used to endorse or promote
-     products derived from this software without specific prior
-     written permission.
- 
-  THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS
-  OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-  ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
-  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
-  GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
-  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
-  IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
-  OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
-  IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-*/
-
-
-
-#include <errno.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include "zip.h"
-
-static const char *prg;
-
-int
-main(int argc, char *argv[])
-{
-    const char *archive;
-    const char *file;
-    const char *name;
-    struct zip *za;
-    struct zip_source *zs;
-    char buf[100];
-    int err;
-    int i;
-    int ret = 0;
-
-    prg = argv[0];
-
-    if (argc < 3) {
-	fprintf(stderr, "usage: %s archive file [file ...]\n", prg);
-	return 1;
-    }
-
-    archive = argv[1];
-    if ((za=zip_open(archive, ZIP_CREATE, &err)) == NULL) {
-	zip_error_to_str(buf, sizeof(buf), err, errno);
-	fprintf(stderr, "can't open zip archive `%s': %s\n",
-		archive, buf);
-	return 1;
-    }
-
-    for (i=2; i<argc; i++) {
-	file = argv[i];
-    
-	if ((zs=zip_source_file(za, file, 0, -1)) == NULL) {
-	    fprintf(stderr, "error creating file source for `%s': %s\n",
-		    file, zip_strerror(za));
-	    ret = 1;
-	    continue;
-	}
-
-	if ((name=strrchr(file, '/')) == NULL)
-	    name = file;
-
-	if (zip_add(za, name, zs) == -1) {
-	    zip_source_free(zs);
-	    fprintf(stderr, "can't add file `%s': %s\n",
-		    file, zip_strerror(za));
-	    ret = 1;
-	}
-    }
-
-    if (zip_close(za) == -1) {
-	fprintf(stderr, "can't close zip archive `%s': %s\n",
-		archive, zip_strerror(za));
-	return 1;
-    }
-
-    return ret;
-}
diff --git a/regress/add_from_file.test b/regress/add_from_file.test
index 279fbe1..9371d66 100644
--- a/regress/add_from_file.test
+++ b/regress/add_from_file.test
@@ -1,6 +1,6 @@
 # add file to zip
-program add_from_file
+program modify
 return 0
-args testfile.zip testfile.txt
+args testfile.zip   add_file testfile.txt testfile.txt 0 -1
 file testfile.txt testfile.txt testfile.txt
 file-new testfile.zip testfile.zip
diff --git a/regress/add_from_file_duplicate.test b/regress/add_from_file_duplicate.test
index 735d1bd..3be6359 100644
--- a/regress/add_from_file_duplicate.test
+++ b/regress/add_from_file_duplicate.test
@@ -1,7 +1,7 @@
 # add already existing file to zip, making duplicate names
-program add_from_file
+program modify
 return 1
-args testfile.zip testfile.txt
+args testfile.zip   add_file testfile.txt testfile.txt 0 -1
 file testfile.txt testfile.txt testfile.txt
 file testfile.zip testfile.zip testfile.zip
 stderr can't add file `testfile.txt': File already exists
diff --git a/regress/add_from_file_twice_duplicate.test b/regress/add_from_file_twice_duplicate.test
index 287624c..0138606 100644
--- a/regress/add_from_file_twice_duplicate.test
+++ b/regress/add_from_file_twice_duplicate.test
@@ -1,7 +1,7 @@
 # add file to zip twice, making duplicate names
-program add_from_file
+program modify
 return 1
-args testfile.zip testfile.txt testfile.txt
+args testfile.zip   add_file testfile.txt testfile.txt 0 -1   add_file testfile.txt testfile.txt 0 -1
 file testfile.txt testfile.txt testfile.txt
 file-new testfile.zip testfile.zip
 stderr can't add file `testfile.txt': File already exists