filter.c File Reference

Expando filtering. More...

#include "config.h"
#include <errno.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include "mutt/lib.h"
#include "gui/lib.h"
#include "expando.h"
#include "node.h"
#include "render.h"

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Functions
bool	check_for_pipe (struct ExpandoNode *root)
	Should the Expando be piped to an external command?
void	filter_text (struct Buffer *buf, char **env_list)
	Filter the text through an external command.
int	expando_filter (const struct Expando *exp, const struct ExpandoRenderCallback *erc, void *data, MuttFormatFlags flags, int max_cols, char **env_list, struct Buffer *buf)
	Render an Expando and run the result through a filter.

Detailed Description

Expando filtering.

Authors

• Richard Russon

Copyright

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, see http://www.gnu.org/licenses/.

Definition in file filter.c.

Function Documentation

check_for_pipe()

bool check_for_pipe

(

struct ExpandoNode *

root

)

Should the Expando be piped to an external command?

Parameters

root

Root Node

Return values

true	Yes, pipe it

• Check the last Node is text
• Check for a trailing | (pipe) character

Definition at line 49 of file filter.c.

{
  if (!root)
    return false;
 
  struct ExpandoNode *last = node_last(root);
  if (!last || (last->type != ENT_TEXT))
    return false;
 
  size_t len = mutt_str_len(last->text);
  if (len < 1)
    return false;
 
  if (last->text[len - 1] != '|')
    return false;
 
  // Count any preceding backslashes
  int count = 0;
  for (int i = len - 2; i >= 0; i--)
  {
    if (last->text[i] == '\\')
      count++;
  }
 
  // The pipe character is escaped with a backslash
  if ((count % 2) != 0)
    return false;
 
  return true;
}

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filter_text()

void filter_text	(	struct Buffer *	buf,
		char **	env_list )

Filter the text through an external command.

Parameters

[in,out]	buf	Text
[in]	env_list	Environment

The text is passed unchanged to the shell. The first line of any output (minus the newline) is stored back in buf.

Definition at line 88 of file filter.c.

{
  // Trim the | (pipe) character
  size_t len = buf_len(buf);
  if (len == 0)
    return;
 
  if (buf->data[len - 1] == '|')
    buf->data[len - 1] = '\0';
 
  mutt_debug(LL_DEBUG3, "execute: %s\n", buf_string(buf));
  FILE *fp_filter = NULL;
  pid_t pid = filter_create(buf_string(buf), NULL, &fp_filter, NULL, env_list);
  if (pid < 0)
    return; // LCOV_EXCL_LINE
 
  buf_reset(buf);
  size_t n = fread(buf->data, 1, buf->dsize - 1, fp_filter);
  buf->data[n] = '\0';
  mutt_file_fclose(&fp_filter);
  buf_fix_dptr(buf);
 
  int rc = filter_wait(pid);
  if (rc != 0)
    mutt_debug(LL_DEBUG1, "filter cmd exited code %d\n", rc);
 
  if (n == 0)
  {
    mutt_debug(LL_DEBUG1, "error reading from filter: %s (errno=%d)\n",
               strerror(errno), errno);
    buf_reset(buf);
    return;
  }
 
  char *nl = (char *) buf_find_char(buf, '\n');
  if (nl)
    *nl = '\0';
  mutt_debug(LL_DEBUG3, "received: %s\n", buf_string(buf));
}

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expando_filter()

int expando_filter	(	const struct Expando *	exp,
		const struct ExpandoRenderCallback *	erc,
		void *	data,
		MuttFormatFlags	flags,
		int	max_cols,
		char **	env_list,
		struct Buffer *	buf )

Render an Expando and run the result through a filter.

Parameters

[in]	exp	Expando containing the expando tree
[in]	erc	Expando Render Callback functions
[in]	data	Callback data
[in]	flags	Callback flags
[in]	max_cols	Number of screen columns (-1 means unlimited)
[in]	env_list	Environment to pass to filter
[out]	buf	Buffer in which to save string

Return values

obj	Number of bytes written to buf and screen columns used

Definition at line 139 of file filter.c.

{
  if (!exp || !exp->node)
    return 0;
 
  struct ExpandoNode *node = exp->node;
 
  bool is_pipe = check_for_pipe(node);
  int old_cols = max_cols;
  if (is_pipe)
    max_cols = -1;
 
  int rc = expando_render(exp, erc, data, flags, max_cols, buf);
 
  if (!is_pipe)
    return rc;
 
  filter_text(buf, env_list);
 
  // Strictly truncate to size
  size_t width = 0;
  size_t bytes = mutt_wstr_trunc(buf_string(buf), buf_len(buf), old_cols, &width);
  buf->data[bytes] = '\0';
 
  return width;
}

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