truncate: new applet

Add the actual new source file :(

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 77 insertions, 0 deletions

diff --git a/coreutils/truncate.c b/coreutils/truncate.c
new file mode 100644
index 000000000..0e36daba3
--- /dev/null
+++ b/coreutils/truncate.c
@@ -0,0 +1,77 @@
+/*
+ * Mini truncate implementation for busybox
+ *
+ * Copyright (C) 2015 by Ari Sundholm <ari@tuxera.com>
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
+
+//config:config TRUNCATE
+//config:       bool "truncate"
+//config:       default y
+//config:       help
+//config:         truncate truncates files to a given size. If a file does
+//config:         not exist, it is created unless told otherwise.
+
+//kbuild:lib-$(CONFIG_TRUNCATE) += truncate.o
+//applet:IF_TRUNCATE(APPLET_NOFORK(truncate, truncate, BB_DIR_USR_BIN, BB_SUID_DROP, truncate))
+
+//usage:#define truncate_trivial_usage
+//usage:       "[-c] -s SIZE FILE..."
+//usage:#define truncate_full_usage "\n\n"
+//usage:        "Truncate FILEs to the given size\n"
+//usage:        "\n     -c      Do not create files"
+//usage:        "\n     -s SIZE Truncate to SIZE"
+//usage:
+//usage:#define truncate_example_usage
+//usage:        "$ truncate -s 1G foo"
+
+#include "libbb.h"
+
+#if ENABLE_LFS
+# define XATOU_SFX xatoull_sfx
+#else
+# define XATOU_SFX xatoul_sfx
+#endif
+
+/* This is a NOFORK applet. Be very careful! */
+
+int truncate_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int truncate_main(int argc UNUSED_PARAM, char **argv)
+{
+        unsigned opts;
+        int flags = O_RDWR;
+        int ret = EXIT_SUCCESS;
+        char *size_str;
+        off_t size;
+
+        enum {
+                OPT_NOCREATE  = (1 << 0),
+                OPT_SIZE = (1 << 1),
+        };
+
+        opt_complementary = "s:-1";
+        opts = getopt32(argv, "cs:", &size_str);
+
+        if (!(opts & OPT_NOCREATE))
+                flags |= O_CREAT;
+
+        // TODO: coreutils 8.17 also support "m" (lowercase) suffix
+        // with truncate, but not with dd!
+        // We share kMG_suffixes[], so we can't make both tools
+        // compatible at once...
+        size = XATOU_SFX(size_str, kMG_suffixes);
+
+        argv += optind;
+        while (*argv) {
+                int fd = xopen(*argv, flags);
+                if (ftruncate(fd, size) == -1) {
+                        bb_perror_msg("%s: ftruncate", *argv);
+                        ret = EXIT_FAILURE;
+                }
+                xclose(fd);
+                ++argv;
+        }
+
+        return ret;
+}