df: Rewrite virt-df in C.

I have diffed the output from the original virt-df with this
new version, and they agree very closely.  Some differences:

 - Old virt-df have a divide-by-zero error in cases where the
   number of used inodes was 0.  New virt-df fixes this.

 - New virt-df uses gnulib human_readable library which displays
   numbers to 3 significant figures for -h output (old version
   used an ad hoc function).

1 files changed, 242 insertions, 0 deletions

diff --git a/df/output.c b/df/output.c
new file mode 100644
index 00000000..52ce0631
--- /dev/null
+++ b/df/output.c
@@ -0,0 +1,242 @@
+/* virt-df
+ * Copyright (C) 2010 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <inttypes.h>
+#include <xvasprintf.h>
+#include <math.h>
+#include <assert.h>
+
+#ifdef HAVE_LIBVIRT
+#include <libvirt/libvirt.h>
+#include <libvirt/virterror.h>
+#endif
+
+#include "c-ctype.h"
+#include "human.h"
+#include "progname.h"
+
+#include "guestfs.h"
+#include "options.h"
+#include "virt-df.h"
+
+static void write_csv_field (const char *field);
+
+void
+print_title (void)
+{
+  const char *cols[6];
+  size_t i;
+
+  cols[0] = _("VirtualMachine");
+  cols[1] = _("Filesystem");
+  if (!inodes) {
+    if (!human)
+      cols[2] = _("1K-blocks");
+    else
+      cols[2] = _("Size");
+    cols[3] = _("Used");
+    cols[4] = _("Available");
+    cols[5] = _("Use%");
+  } else {
+    cols[2] = _("Inodes");
+    cols[3] = _("IUsed");
+    cols[4] = _("IFree");
+    cols[5] = _("IUse%");
+  }
+
+  if (!csv) {
+    /* ignore cols[0] in this mode */
+    printf ("%-36s%10s %10s %10s %5s\n",
+            cols[1], cols[2], cols[3], cols[4], cols[5]);
+  }
+  else {
+    size_t i;
+
+    for (i = 0; i < 6; ++i) {
+      if (i > 0)
+        putchar (',');
+      write_csv_field (cols[i]);
+    }
+    putchar ('\n');
+  }
+}
+
+static void canonical_device (char *dev, int offset);
+
+void
+print_stat (const char *name, const char *uuid_param,
+            const char *dev_param, int offset,
+            const struct guestfs_statvfs *stat)
+{
+  /* First two columns are always 'name' and 'dev', followed by four
+   * other data columns.  In text mode the 'name' and 'dev' are
+   * combined into a single 'name:dev' column.  In CSV mode they are
+   * kept as two separate columns.  In UUID mode the name might be
+   * replaced by 'uuid', if available.
+   */
+#define MAX_LEN (LONGEST_HUMAN_READABLE > 128 ? LONGEST_HUMAN_READABLE : 128)
+  char buf[4][MAX_LEN];
+  const char *cols[4];
+  int64_t factor, v;
+  float percent;
+  int hopts = human_round_to_nearest|human_autoscale|human_base_1024|human_SI;
+  size_t i, len;
+
+  /* Make the device canonical. */
+  len = strlen (dev_param) + 1;
+  char dev[len];
+  strcpy (dev, dev_param);
+  if (offset >= 0)
+    canonical_device (dev, offset);
+
+  if (!inodes) {                /* 1K blocks */
+    if (!human) {
+      factor = stat->bsize / 1024;
+
+      v = stat->blocks * factor;
+      snprintf (buf[0], MAX_LEN, "%" PRIi64, v);
+      cols[0] = buf[0];
+      v = (stat->blocks - stat->bfree) * factor;
+      snprintf (buf[1], MAX_LEN, "%" PRIi64, v);
+      cols[1] = buf[1];
+      v = stat->bavail * factor;
+      snprintf (buf[2], MAX_LEN, "%" PRIi64, v);
+      cols[2] = buf[2];
+    } else {
+      cols[0] =
+        human_readable ((uintmax_t) stat->blocks, buf[0],
+                        hopts, stat->bsize, 1);
+      v = stat->blocks - stat->bfree;
+      cols[1] =
+        human_readable ((uintmax_t) v, buf[1], hopts, stat->bsize, 1);
+      cols[2] =
+        human_readable ((uintmax_t) stat->bavail, buf[2],
+                        hopts, stat->bsize, 1);
+    }
+
+    if (stat->blocks != 0)
+      percent = 100. - 100. * stat->bfree / stat->blocks;
+    else
+      percent = 0;
+  }
+  else {                        /* inodes */
+    snprintf (buf[0], MAX_LEN, "%" PRIi64, stat->files);
+    cols[0] = buf[0];
+    snprintf (buf[1], MAX_LEN, "%" PRIi64, stat->files - stat->ffree);
+    cols[1] = buf[1];
+    snprintf (buf[2], MAX_LEN, "%" PRIi64, stat->ffree);
+    cols[2] = buf[2];
+
+    if (stat->files != 0)
+      percent = 100. - 100. * stat->ffree / stat->files;
+    else
+      percent = 0;
+  }
+
+  if (!csv)
+    /* Use 'ceil' on the percentage in order to emulate what df itself does. */
+    snprintf (buf[3], MAX_LEN, "%3.0f%%", ceil (percent));
+  else
+    snprintf (buf[3], MAX_LEN, "%.1f", percent);
+  cols[3] = buf[3];
+
+#undef MAX_LEN
+
+  if (uuid && uuid_param)
+    name = uuid_param;
+
+  if (!csv) {
+    len = strlen (name) + strlen (dev) + 1;
+    printf ("%s:%s", name, dev);
+    if (len <= 36) {
+      for (i = len; i < 36; ++i)
+        putchar (' ');
+    } else {
+      printf ("\n                                    ");
+    }
+
+    printf ("%10s %10s %10s %5s\n", cols[0], cols[1], cols[2], cols[3]);
+  }
+  else {
+    write_csv_field (name);
+    putchar (',');
+    write_csv_field (dev);
+
+    for (i = 0; i < 4; ++i) {
+      putchar (',');
+      write_csv_field (cols[i]);
+    }
+
+    putchar ('\n');
+  }
+}
+
+/* /dev/vda1 -> /dev/sda, adjusting the device offset. */
+static void
+canonical_device (char *dev, int offset)
+{
+  if (STRPREFIX (dev, "/dev/") &&
+      (dev[5] == 'h' || dev[5] == 'v') &&
+      dev[6] == 'd' &&
+      c_isalpha (dev[7]) &&
+      (c_isdigit (dev[8]) || dev[8] == '\0')) {
+    dev[5] = 's';
+    dev[7] -= offset;
+  }
+}
+
+/* Function to quote CSV fields on output without requiring an
+ * external module.
+ */
+static void
+write_csv_field (const char *field)
+{
+  size_t i, len;
+  int needs_quoting = 0;
+
+  len = strlen (field);
+
+  for (i = 0; i < len; ++i) {
+    if (field[i] == ' ' || field[i] == '"' ||
+        field[i] == '\n' || field[i] == ',') {
+      needs_quoting = 1;
+      break;
+    }
+  }
+
+  if (!needs_quoting) {
+    printf ("%s", field);
+    return;
+  }
+
+  /* Quoting for CSV fields. */
+  putchar ('"');
+  for (i = 0; i < len; ++i) {
+    if (field[i] == '"') {
+      putchar ('"');
+      putchar ('"');
+    } else
+      putchar (field[i]);
+  }
+  putchar ('"');
+}