mostly splitting the source

Signed-off-by: Mattias Andrée <maandree@member.fsf.org>

1 files changed, 151 insertions, 0 deletions

diff --git a/src/pattern.c b/src/pattern.c
new file mode 100644
index 0000000..6912731
--- /dev/null
+++ b/src/pattern.c
@@ -0,0 +1,151 @@
+/**
+ * scrotty — Screenshot program for Linux's TTY
+ * 
+ * Copyright © 2014, 2015  Mattias Andrée (maandree@member.fsf.org)
+ * 
+ * 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 3 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, see <http://www.gnu.org/licenses/>.
+ */
+#include "common.h"
+#include "pattern.h"
+
+
+
+/**
+ * Duplicate all '%':s in a buffer until the first occurrence of a zero byte.
+ * 
+ * @param   buf  The buffer.
+ * @param   n    The size of the buffer.
+ * @return       -1 if the buffer is too small, otherwise.
+ *               the new position of the first zero byte.
+ */
+static ssize_t
+duplicate_percents (char *restrict buf, size_t n)
+{
+  size_t p = 0, pi, pc = 0, i;
+  
+  /* Count number of '%':s. */
+  for (i = 0; buf[i]; i++)
+    if (buf[i] == '%')
+      pc++;
+  
+  /* Check whether the string will overflow. */
+  if (i + pc > n)
+    return -1;
+  
+  /* Duplicate all '%':s. */
+  for (pi = 0; pi < pc; pi++)
+    {
+      p = (size_t)(strchr (buf + p, '%') - buf);
+      memmove (buf + p + 1, buf + p, (i - (p - pi)) * sizeof (char));
+      p += 2;
+    }
+  
+  return (ssize_t)(i + pi);
+}
+
+
+/**
+ * Parse and evaluate a --exec argument or filename pattern.
+ * 
+ * If `path != NULL` than all non-escaped spaces in
+ * `pattern` will be stored as 255-bytes in `buf`.
+ * 
+ * @param   buf      The output buffer.
+ * @param   n        The size of `buf`.
+ * @param   pattern  The pattern to evaluate.
+ * @param   fbno     The index of the framebuffer.
+ * @param   width    The width of the image/framebuffer.
+ * @param   height   The height of the image/framebuffer.
+ * @param   path     The filename of the saved image, `NULL`
+ *                   during the evaluation of the filename pattern.
+ * @return           Zero on success, -1 on error.
+ */
+int
+evaluate (char *restrict buf, size_t n, const char *restrict pattern,
+	  int fbno, long width, long height, const char *restrict path)
+{
+#define P(format, value)  r = snprintf (buf + i, n - i, format "%zn", value, &j)
+  
+  size_t i = 0;
+  ssize_t j = 0;
+  int percent = 0, backslash = 0, dollar = 0, r;
+  char c;
+  char *fmt;
+  time_t t;
+  struct tm *tm;
+  
+  /* Expand '$' and '\'. */
+  while ((i < n) && ((c = *pattern++)))
+    if (dollar)
+      {
+	dollar = 0;
+	if (path == NULL)
+	  if ((c == 'f') || (c == 'n'))
+	    continue;
+	if      (c == 'i')  P ("%i", fbno);
+	else if (c == 'f')  P ("%s", path);
+	else if (c == 'n')  P ("%s", strrchr (path, '/') ? (strrchr (path, '/') + 1) : path);
+	else if (c == 'p')  P ("%ju", (uintmax_t)width * (uintmax_t)height);
+	else if (c == 'w')  P ("%li", width);
+	else if (c == 'h')  P ("%li", height);
+	else if (c == '$')  r = 0, j = 1, buf[i] = '$';
+	else if ((r < 0) || (j <= 0))
+	  return -1;
+	else if ((c == 'f') || (c == 'n'))
+	  if (j = duplicate_percents (buf + i, n - i), j < 0)
+	    goto enametoolong;
+	i += (size_t)j;
+      }
+    else if (backslash)  buf[i++] = (c == 'n' ? '\n' : c), backslash = 0;
+    else if (percent)    buf[i++] = c, percent = 0;
+    else if (c == '%')   buf[i++] = c, percent = 1;
+    else if (c == '\\')  backslash = 1;
+    else if (c == '$')   dollar = 1;
+    else if (c == ' ')   buf[i++] = path == NULL ? ' ' : (char)255; /* 255 is not valid in UTF-8. */
+    else                 buf[i++] = c;
+  if (i >= n)
+    goto enametoolong;
+  buf[i] = '\0';
+  
+  /* Check whether there are any '%' to expand. */
+  if (strchr (buf, '%') == NULL)
+    return 0;
+  
+  /* Copy the buffer so we can reuse the buffer and use its old content for the format. */
+  fmt = alloca ((strlen (buf) + 1) * sizeof (char));
+  memcpy (fmt, buf, (strlen (buf) + 1) * sizeof (char));
+  
+  /* Expand '%'. */
+  t = time (NULL);
+  tm = localtime (&t);
+  if (tm == NULL)
+    goto fail;
+  
+#ifdef __GNUC__
+# pragma GCC diagnostic ignored "-Wformat-nonliteral"
+#endif
+  if (strftime (buf, n, fmt, tm) == 0)
+    goto enametoolong; /* No errors are defined for `strftime`. What else can we do? */
+  
+  return 0;
+  
+ enametoolong:
+  return errno = ENAMETOOLONG, -1;
+  
+ fail:
+  return -1;
+  
+#undef P
+}
+