regex.c File Reference

Manage regular expressions. More...

#include "config.h"
#include <ctype.h>
#include <regex.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "atoi.h"
#include "buffer.h"
#include "logging.h"
#include "mbyte.h"
#include "memory.h"
#include "message.h"
#include "queue.h"
#include "regex3.h"
#include "string2.h"

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Functions
struct Regex *	mutt_regex_compile (const char *str, uint16_t flags)
	Create an Regex from a string. More...
struct Regex *	mutt_regex_new (const char *str, uint32_t flags, struct Buffer *err)
	Create an Regex from a string. More...
void	mutt_regex_free (struct Regex **r)
	Free a Regex object. More...
int	mutt_regexlist_add (struct RegexList *rl, const char *str, uint16_t flags, struct Buffer *err)
	Compile a regex string and add it to a list. More...
void	mutt_regexlist_free (struct RegexList *rl)
	Free a RegexList object. More...
bool	mutt_regexlist_match (struct RegexList *rl, const char *str)
	Does a string match any Regex in the list? More...
struct RegexNode *	mutt_regexlist_new (void)
	Create a new RegexList. More...
int	mutt_regexlist_remove (struct RegexList *rl, const char *str)
	Remove a Regex from a list. More...
int	mutt_replacelist_add (struct ReplaceList *rl, const char *pat, const char *templ, struct Buffer *err)
	Add a pattern and a template to a list. More...
char *	mutt_replacelist_apply (struct ReplaceList *rl, char *buf, size_t buflen, const char *str)
	Apply replacements to a buffer. More...
void	mutt_replacelist_free (struct ReplaceList *rl)
	Free a ReplaceList object. More...
bool	mutt_replacelist_match (struct ReplaceList *rl, char *buf, size_t buflen, const char *str)
	Does a string match a pattern? More...
struct Replace *	mutt_replacelist_new (void)
	Create a new ReplaceList. More...
int	mutt_replacelist_remove (struct ReplaceList *rl, const char *pat)
	Remove a pattern from a list. More...
bool	mutt_regex_capture (const struct Regex *regex, const char *str, size_t nmatch, regmatch_t matches[])
	Match a regex against a string, with provided options. More...
bool	mutt_regex_match (const struct Regex *regex, const char *str)
	Shorthand to mutt_regex_capture() More...

Detailed Description

Manage regular expressions.

Authors

• Richard Russon
• Simon Symeonidis

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 regex.c.

Function Documentation

mutt_regex_compile()

struct Regex * mutt_regex_compile	(	const char *	str,
		uint16_t	flags
	)

Create an Regex from a string.

Parameters

str	Regular expression
flags	Type flags, e.g. REG_ICASE

Return values

ptr	New Regex object
NULL	Error

Definition at line 55 of file regex.c.

{
  if (!str || (*str == '\0'))
    return NULL;
  struct Regex *rx = mutt_mem_calloc(1, sizeof(struct Regex));
  rx->pattern = mutt_str_dup(str);
  rx->regex = mutt_mem_calloc(1, sizeof(regex_t));
  if (REG_COMP(rx->regex, str, flags) != 0)
    mutt_regex_free(&rx);
 
  return rx;
}

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mutt_regex_new()

struct Regex * mutt_regex_new	(	const char *	str,
		uint32_t	flags,
		struct Buffer *	err
	)

Create an Regex from a string.

Parameters

str	Regular expression
flags	Type flags, e.g. DT_REGEX_MATCH_CASE
err	Buffer for error messages

Return values

ptr	New Regex object
NULL	Error

Definition at line 76 of file regex.c.

{
  if (!str || (*str == '\0'))
    return NULL;
 
  uint16_t rflags = 0;
  struct Regex *reg = mutt_mem_calloc(1, sizeof(struct Regex));
 
  reg->regex = mutt_mem_calloc(1, sizeof(regex_t));
  reg->pattern = mutt_str_dup(str);
 
  /* Should we use smart case matching? */
  if (((flags & DT_REGEX_MATCH_CASE) == 0) && mutt_mb_is_lower(str))
    rflags |= REG_ICASE;
 
  /* Is a prefix of '!' allowed? */
  if (((flags & DT_REGEX_ALLOW_NOT) != 0) && (str[0] == '!'))
  {
    reg->pat_not = true;
    str++;
  }
 
  int rc = REG_COMP(reg->regex, str, rflags);
  if (rc != 0)
  {
    if (err)
      regerror(rc, reg->regex, err->data, err->dsize);
    mutt_regex_free(&reg);
    return NULL;
  }
 
  return reg;
}

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mutt_regex_free()

void mutt_regex_free

(

struct Regex **

r

)

Free a Regex object.

Parameters

[out]

r

Regex to free

Definition at line 114 of file regex.c.

{
  if (!r || !*r)
    return;
 
  FREE(&(*r)->pattern);
  if ((*r)->regex)
    regfree((*r)->regex);
  FREE(&(*r)->regex);
  FREE(r);
}

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mutt_regexlist_add()

int mutt_regexlist_add	(	struct RegexList *	rl,
		const char *	str,
		uint16_t	flags,
		struct Buffer *	err
	)

Compile a regex string and add it to a list.

Parameters

rl	RegexList to add to
str	String to compile into a regex
flags	Flags, e.g. REG_ICASE
err	Buffer for error messages

Return values

0	Success, Regex compiled and added to the list
-1	Error, see message in 'err'

Definition at line 135 of file regex.c.

{
  if (!rl || !str || (*str == '\0'))
    return 0;
 
  struct Regex *rx = mutt_regex_compile(str, flags);
  if (!rx)
  {
    mutt_buffer_printf(err, "Bad regex: %s\n", str);
    return -1;
  }
 
  /* check to make sure the item is not already on this rl */
  struct RegexNode *np = NULL;
  STAILQ_FOREACH(np, rl, entries)
  {
    if (mutt_istr_equal(rx->pattern, np->regex->pattern))
      break; /* already on the rl */
  }
 
  if (np)
  {
    mutt_regex_free(&rx);
  }
  else
  {
    np = mutt_regexlist_new();
    np->regex = rx;
    STAILQ_INSERT_TAIL(rl, np, entries);
  }
 
  return 0;
}

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mutt_regexlist_free()

void mutt_regexlist_free

(

struct RegexList *

rl

)

Free a RegexList object.

Parameters

rl	RegexList to free

Definition at line 174 of file regex.c.

{
  if (!rl)
    return;
 
  struct RegexNode *np = NULL, *tmp = NULL;
  STAILQ_FOREACH_SAFE(np, rl, entries, tmp)
  {
    STAILQ_REMOVE(rl, np, RegexNode, entries);
    mutt_regex_free(&np->regex);
    FREE(&np);
  }
  STAILQ_INIT(rl);
}

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mutt_regexlist_match()

bool mutt_regexlist_match	(	struct RegexList *	rl,
		const char *	str
	)

Does a string match any Regex in the list?

Parameters

rl	RegexList to match against
str	String to compare

Return values

true	String matches one of the Regexes in the list

Definition at line 195 of file regex.c.

{
  if (!rl || !str)
    return false;
  struct RegexNode *np = NULL;
  STAILQ_FOREACH(np, rl, entries)
  {
    if (mutt_regex_match(np->regex, str))
    {
      mutt_debug(LL_DEBUG5, "%s matches %s\n", str, np->regex->pattern);
      return true;
    }
  }
 
  return false;
}

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mutt_regexlist_new()

struct RegexNode * mutt_regexlist_new

(

void

)

Create a new RegexList.

Return values

ptr	New RegexList object

Definition at line 216 of file regex.c.

{
  return mutt_mem_calloc(1, sizeof(struct RegexNode));
}

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mutt_regexlist_remove()

int mutt_regexlist_remove	(	struct RegexList *	rl,
		const char *	str
	)

Remove a Regex from a list.

Parameters

rl	RegexList to alter
str	Pattern to remove from the list

Return values

0	Success, pattern was found and removed from the list
-1	Error, pattern wasn't found

If the pattern is "*", then all the Regexes are removed.

Definition at line 230 of file regex.c.

{
  if (!rl || !str)
    return -1;
 
  if (mutt_str_equal("*", str))
  {
    mutt_regexlist_free(rl); /* "unCMD *" means delete all current entries */
    return 0;
  }
 
  int rc = -1;
  struct RegexNode *np = NULL, *tmp = NULL;
  STAILQ_FOREACH_SAFE(np, rl, entries, tmp)
  {
    if (mutt_istr_equal(str, np->regex->pattern))
    {
      STAILQ_REMOVE(rl, np, RegexNode, entries);
      mutt_regex_free(&np->regex);
      FREE(&np);
      rc = 0;
    }
  }
 
  return rc;
}

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mutt_replacelist_add()

int mutt_replacelist_add	(	struct ReplaceList *	rl,
		const char *	pat,
		const char *	templ,
		struct Buffer *	err
	)

Add a pattern and a template to a list.

Parameters

rl	ReplaceList to add to
pat	Pattern to compile into a regex
templ	Template string to associate with the pattern
err	Buffer for error messages

Return values

0	Success, pattern added to the ReplaceList
-1	Error, see message in 'err'

Definition at line 266 of file regex.c.

{
  if (!rl || !pat || (*pat == '\0') || !templ)
    return 0;
 
  struct Regex *rx = mutt_regex_compile(pat, REG_ICASE);
  if (!rx)
  {
    if (err)
      mutt_buffer_printf(err, _("Bad regex: %s"), pat);
    return -1;
  }
 
  /* check to make sure the item is not already on this rl */
  struct Replace *np = NULL;
  STAILQ_FOREACH(np, rl, entries)
  {
    if (mutt_istr_equal(rx->pattern, np->regex->pattern))
    {
      /* Already on the rl. Formerly we just skipped this case, but
       * now we're supporting removals, which means we're supporting
       * re-adds conceptually. So we probably want this to imply a
       * removal, then do an add. We can achieve the removal by freeing
       * the template, and leaving t pointed at the current item.  */
      FREE(&np->templ);
      break;
    }
  }
 
  /* If np is set, it's pointing into an extant ReplaceList* that we want to
   * update. Otherwise we want to make a new one to link at the rl's end.  */
  if (np)
  {
    mutt_regex_free(&rx);
  }
  else
  {
    np = mutt_replacelist_new();
    np->regex = rx;
    rx = NULL;
    STAILQ_INSERT_TAIL(rl, np, entries);
  }
 
  /* Now np is the Replace that we want to modify. It is prepared. */
  np->templ = mutt_str_dup(templ);
 
  /* Find highest match number in template string */
  np->nmatch = 0;
  for (const char *p = templ; *p;)
  {
    if (*p == '%')
    {
      int n = 0;
      const char *end = mutt_str_atoi(++p, &n);
      if (!end)
      {
        // this is not an error, we might have matched %R or %L in subjectrx
        mutt_debug(LL_DEBUG2, "Invalid match number in replacelist: '%s'\n", p);
      }
      if (n > np->nmatch)
      {
        np->nmatch = n;
      }
      if (end)
      {
        p = end;
      }
      else
      {
        p++;
      }
    }
    else
    {
      p++;
    }
  }
 
  if (np->nmatch > np->regex->regex->re_nsub)
  {
    if (err)
      mutt_buffer_printf(err, "%s", _("Not enough subexpressions for template"));
    mutt_replacelist_remove(rl, pat);
    return -1;
  }
 
  np->nmatch++; /* match 0 is always the whole expr */
  return 0;
}

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mutt_replacelist_apply()

char * mutt_replacelist_apply	(	struct ReplaceList *	rl,
		char *	buf,
		size_t	buflen,
		const char *	str
	)

Apply replacements to a buffer.

Parameters

rl	ReplaceList to apply
buf	Buffer for the result
buflen	Length of the buffer
str	String to manipulate

Return values

ptr	Pointer to 'buf'

If 'buf' is NULL, a new string will be returned. It must be freed by the caller.

Note

This function uses a fixed size buffer of 1024 and so should only be used for visual modifications, such as disp_subj.

Definition at line 370 of file regex.c.

{
  static regmatch_t *pmatch = NULL;
  static size_t nmatch = 0;
  static char twinbuf[2][1024];
  int switcher = 0;
  char *p = NULL;
  size_t cpysize, tlen;
  char *src = NULL, *dst = NULL;
 
  if (buf && (buflen != 0))
    buf[0] = '\0';
 
  if (!rl || !str || (*str == '\0') || (buf && (buflen == 0)))
    return buf;
 
  twinbuf[0][0] = '\0';
  twinbuf[1][0] = '\0';
  src = twinbuf[switcher];
  dst = src;
 
  mutt_str_copy(src, str, sizeof(*twinbuf));
 
  struct Replace *np = NULL;
  STAILQ_FOREACH(np, rl, entries)
  {
    /* If this pattern needs more matches, expand pmatch. */
    if (np->nmatch > nmatch)
    {
      mutt_mem_realloc(&pmatch, np->nmatch * sizeof(regmatch_t));
      nmatch = np->nmatch;
    }
 
    if (mutt_regex_capture(np->regex, src, np->nmatch, pmatch))
    {
      tlen = 0;
      switcher ^= 1;
      dst = twinbuf[switcher];
 
      mutt_debug(LL_DEBUG5, "%s matches %s\n", src, np->regex->pattern);
 
      /* Copy into other twinbuf with substitutions */
      if (np->templ)
      {
        for (p = np->templ; *p && (tlen < (sizeof(*twinbuf) - 1));)
        {
          if (*p == '%')
          {
            p++;
            if (*p == 'L')
            {
              p++;
              cpysize = MIN(pmatch[0].rm_so, (sizeof(*twinbuf) - 1) - tlen);
              strncpy(&dst[tlen], src, cpysize);
              tlen += cpysize;
            }
            else if (*p == 'R')
            {
              p++;
              cpysize = MIN(strlen(src) - pmatch[0].rm_eo, (sizeof(*twinbuf) - 1) - tlen);
              strncpy(&dst[tlen], &src[pmatch[0].rm_eo], cpysize);
              tlen += cpysize;
            }
            else
            {
              long n = strtoul(p, &p, 10); /* get subst number */
              if (n < np->nmatch)
              {
                while (isdigit((unsigned char) *p)) /* skip subst token */
                  p++;
                for (int i = pmatch[n].rm_so;
                     (i < pmatch[n].rm_eo) && (tlen < (sizeof(*twinbuf) - 1)); i++)
                {
                  dst[tlen++] = src[i];
                }
              }
            }
          }
          else
          {
            dst[tlen++] = *p++;
          }
        }
      }
      dst[tlen] = '\0';
      mutt_debug(LL_DEBUG5, "subst %s\n", dst);
    }
    src = dst;
  }
 
  if (buf)
    mutt_str_copy(buf, dst, buflen);
  else
    buf = mutt_str_dup(dst);
  return buf;
}

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mutt_replacelist_free()

void mutt_replacelist_free

(

struct ReplaceList *

rl

)

Free a ReplaceList object.

Parameters

rl	ReplaceList to free

Definition at line 471 of file regex.c.

{
  if (!rl)
    return;
 
  struct Replace *np = NULL, *tmp = NULL;
  STAILQ_FOREACH_SAFE(np, rl, entries, tmp)
  {
    STAILQ_REMOVE(rl, np, Replace, entries);
    mutt_regex_free(&np->regex);
    FREE(&np->templ);
    FREE(&np);
  }
}

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mutt_replacelist_match()

bool mutt_replacelist_match	(	struct ReplaceList *	rl,
		char *	buf,
		size_t	buflen,
		const char *	str
	)

Does a string match a pattern?

Parameters

rl	ReplaceList of patterns
buf	Buffer to save match
buflen	Buffer length
str	String to check

Return values

true	String matches a patterh in the ReplaceList

Match a string against the patterns defined by the 'spam' command and output the expanded format into buf when there is a match. If buflen<=0, the match is performed but the format is not expanded and no assumptions are made about the value of buf so it may be NULL.

Definition at line 499 of file regex.c.

{
  if (!rl || !buf || !str)
    return false;
 
  static regmatch_t *pmatch = NULL;
  static size_t nmatch = 0;
  int tlen = 0;
  char *p = NULL;
 
  struct Replace *np = NULL;
  STAILQ_FOREACH(np, rl, entries)
  {
    /* If this pattern needs more matches, expand pmatch. */
    if (np->nmatch > nmatch)
    {
      mutt_mem_realloc(&pmatch, np->nmatch * sizeof(regmatch_t));
      nmatch = np->nmatch;
    }
 
    /* Does this pattern match? */
    if (mutt_regex_capture(np->regex, str, (size_t) np->nmatch, pmatch))
    {
      mutt_debug(LL_DEBUG5, "%s matches %s\n", str, np->regex->pattern);
      mutt_debug(LL_DEBUG5, "%d subs\n", (int) np->regex->regex->re_nsub);
 
      /* Copy template into buf, with substitutions. */
      for (p = np->templ; *p && (tlen < (buflen - 1));)
      {
        /* backreference to pattern match substring, eg. %1, %2, etc) */
        if (*p == '%')
        {
          char *e = NULL; /* used as pointer to end of integer backreference in strtol() call */
 
          p++; /* skip over % char */
          long n = strtol(p, &e, 10);
          /* Ensure that the integer conversion succeeded (e!=p) and bounds check.  The upper bound check
           * should not strictly be necessary since add_to_spam_list() finds the largest value, and
           * the static array above is always large enough based on that value. */
          if ((e != p) && (n >= 0) && (n < np->nmatch) && (pmatch[n].rm_so != -1))
          {
            /* copy as much of the substring match as will fit in the output buffer, saving space for
             * the terminating nul char */
            for (int idx = pmatch[n].rm_so;
                 (idx < pmatch[n].rm_eo) && (tlen < (buflen - 1)); idx++)
            {
              buf[tlen++] = str[idx];
            }
          }
          p = e; /* skip over the parsed integer */
        }
        else
        {
          buf[tlen++] = *p++;
        }
      }
      /* tlen should always be less than buflen except when buflen<=0
       * because the bounds checks in the above code leave room for the
       * terminal nul char.   This should avoid returning an unterminated
       * string to the caller.  When buflen<=0 we make no assumption about
       * the validity of the buf pointer. */
      if (tlen < buflen)
      {
        buf[tlen] = '\0';
        mutt_debug(LL_DEBUG5, "\"%s\"\n", buf);
      }
      return true;
    }
  }
 
  return false;
}

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mutt_replacelist_new()

struct Replace * mutt_replacelist_new

(

void

)

Create a new ReplaceList.

Return values

ptr	New ReplaceList

Definition at line 576 of file regex.c.

{
  return mutt_mem_calloc(1, sizeof(struct Replace));
}

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mutt_replacelist_remove()

int mutt_replacelist_remove	(	struct ReplaceList *	rl,
		const char *	pat
	)

Remove a pattern from a list.

Parameters

rl	ReplaceList to modify
pat	Pattern to remove

Return values

num	Matching patterns removed

Definition at line 587 of file regex.c.

{
  if (!rl || !pat)
    return 0;
 
  int nremoved = 0;
  struct Replace *np = NULL, *tmp = NULL;
  STAILQ_FOREACH_SAFE(np, rl, entries, tmp)
  {
    if (mutt_str_equal(np->regex->pattern, pat))
    {
      STAILQ_REMOVE(rl, np, Replace, entries);
      mutt_regex_free(&np->regex);
      FREE(&np->templ);
      FREE(&np);
      nremoved++;
    }
  }
 
  return nremoved;
}

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mutt_regex_capture()

bool mutt_regex_capture	(	const struct Regex *	regex,
		const char *	str,
		size_t	nmatch,
		regmatch_t	matches[]
	)

Match a regex against a string, with provided options.

Parameters

regex	Regex to execute
str	String to apply regex on
nmatch	Length of matches
matches	regmatch_t to hold match indices

Return values

true	str matches
false	str does not match

Definition at line 618 of file regex.c.

{
  if (!regex || !str || !regex->regex)
    return false;
 
  int rc = regexec(regex->regex, str, nmatch, matches, 0);
  return ((rc == 0) ^ regex->pat_not);
}

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mutt_regex_match()

bool mutt_regex_match	(	const struct Regex *	regex,
		const char *	str
	)

Shorthand to mutt_regex_capture()

Parameters

regex	Regex which is desired to match against
str	String to search with given regex

Return values

true	str matches
false	str does not match

Definition at line 635 of file regex.c.

{
  return mutt_regex_capture(regex, str, 0, NULL);
}

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