path.c

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#include "config.h"
#include <errno.h>
#include <libgen.h>
#include <limits.h>
#include <pwd.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "path.h"
#include "buffer.h"
#include "logging2.h"
#include "memory.h"
#include "message.h"
#include "string2.h"
 
bool mutt_path_tidy_slash(char *buf, bool is_dir)
{
  if (!buf)
    return false;
 
  char *r = buf;
  char *w = buf;
 
  while (*r != '\0')
  {
    *w++ = *r++;
 
    if (r[-1] == '/') /* After a '/' ... */
    {
      for (; (r[0] == '/') || (r[0] == '.'); r++)
      {
        if (r[0] == '/') /* skip multiple /s */
          continue;
        if (r[0] == '.')
        {
          if (r[1] == '/') /* skip /./ */
          {
            r++;
            continue;
          }
          else if (r[1] == '\0') /* skip /.$ */
          {
            r[0] = '\0';
          }
          break; /* dot-anything-else isn't special */
        }
      }
    }
  }
 
  /* Strip a trailing / as long as it's not the only character */
  if (is_dir && (w > (buf + 1)) && (w[-1] == '/'))
    w--;
 
  *w = '\0';
 
  return true;
}
 
bool mutt_path_tidy_dotdot(char *buf)
{
  if (!buf || (buf[0] != '/'))
    return false;
 
  char *dd = buf;
 
  mutt_debug(LL_DEBUG3, "Collapse path: %s\n", buf);
  while ((dd = strstr(dd, "/..")))
  {
    if (dd[3] == '/') /* paths follow dots */
    {
      char *dest = NULL;
      if (dd != buf) /* not at start of string */
      {
        dd[0] = '\0';
        dest = strrchr(buf, '/');
      }
      if (!dest)
        dest = buf;
 
      memmove(dest, dd + 3, strlen(dd + 3) + 1);
    }
    else if (dd[3] == '\0') /* dots at end of string */
    {
      if (dd == buf) /* at start of string */
      {
        dd[1] = '\0';
      }
      else
      {
        dd[0] = '\0';
        char *s = strrchr(buf, '/');
        if (s == buf)
          s[1] = '\0';
        else if (s)
          s[0] = '\0';
      }
    }
    else
    {
      dd += 3; /* skip over '/..dir/' */
      continue;
    }
 
    dd = buf; /* restart at the beginning */
  }
 
  mutt_debug(LL_DEBUG3, "Collapsed to:  %s\n", buf);
  return true;
}
 
bool mutt_path_tidy(struct Buffer *path, bool is_dir)
{
  if (buf_is_empty(path) || (buf_at(path, 0) != '/'))
    return false;
 
  if (!mutt_path_tidy_slash(path->data, is_dir))
    return false; // LCOV_EXCL_LINE
 
  mutt_path_tidy_dotdot(path->data);
  buf_fix_dptr(path);
 
  return true;
}
 
bool mutt_path_pretty(struct Buffer *path, const char *homedir, bool is_dir)
{
  if (buf_is_empty(path))
    return false;
 
  mutt_path_tidy(path, is_dir);
 
  size_t len = mutt_str_startswith(path->data, homedir);
  if (len == 0)
    return false;
 
  if ((buf_at(path, len) != '/') && (buf_at(path, len) != '\0'))
    return false;
 
  path->data[0] = '~';
  if (buf_len(path) == len)
  {
    path->data[1] = '\0';
    buf_fix_dptr(path);
    return true;
  }
 
  mutt_str_copy(path->data + 1, path->data + len, buf_len(path) + 1 - len);
  buf_fix_dptr(path);
  return true;
}
 
bool mutt_path_tilde(struct Buffer *path, const char *homedir)
{
  if (buf_is_empty(path) || (buf_at(path, 0) != '~'))
    return false;
 
  char result[PATH_MAX] = { 0 };
  char *dir = NULL;
  size_t len = 0;
 
  if ((buf_at(path, 1) == '/') || (buf_at(path, 1) == '\0'))
  {
    if (!homedir)
    {
      mutt_debug(LL_DEBUG3, "no homedir\n");
      return false;
    }
 
    len = mutt_str_copy(result, homedir, sizeof(result));
    dir = path->data + 1;
  }
  else
  {
    char user[128] = { 0 };
    dir = strchr(path->data + 1, '/');
    if (dir)
      mutt_str_copy(user, path->data + 1, MIN(dir - path->data, (unsigned) sizeof(user)));
    else
      mutt_str_copy(user, path->data + 1, sizeof(user));
 
    struct passwd *pw = getpwnam(user);
    if (!pw || !pw->pw_dir)
    {
      mutt_debug(LL_DEBUG1, "no such user: %s\n", user);
      return false;
    }
 
    len = mutt_str_copy(result, pw->pw_dir, sizeof(result));
  }
 
  mutt_str_copy(result + len, dir, sizeof(result) - len);
  buf_strcpy(path, result);
 
  return true;
}
 
bool mutt_path_canon(struct Buffer *path, const char *homedir, bool is_dir)
{
  if (buf_is_empty(path))
    return false;
 
  if (buf_at(path, 0) == '~')
  {
    mutt_path_tilde(path, homedir);
  }
  else if (buf_at(path, 0) != '/')
  {
    char cwd[PATH_MAX] = { 0 };
    if (!getcwd(cwd, sizeof(cwd)))
    {
      mutt_debug(LL_DEBUG1, "getcwd failed: %s (%d)\n", strerror(errno), errno); // LCOV_EXCL_LINE
      return false; // LCOV_EXCL_LINE
    }
 
    size_t cwd_len = mutt_str_len(cwd);
    cwd[cwd_len] = '/';
    cwd[cwd_len + 1] = '\0';
    buf_insert(path, 0, cwd);
  }
 
  return mutt_path_tidy(path, is_dir);
}
 
const char *mutt_path_basename(const char *path)
{
  if (!path)
    return NULL;
 
  const char *p = strrchr(path, '/');
  if (p)
  {
    if (p[1] == '\0')
      return path;
 
    return p + 1;
  }
 
  return path;
}
 
char *mutt_path_concat(char *dest, const char *dir, const char *file, size_t dlen)
{
  if (!dest || (!dir && !file))
    return NULL;
 
  if (dir && (!file || (file[0] == '\0')))
  {
    strncpy(dest, dir, dlen);
    return dest;
  }
 
  if (file && (!dir || (dir[0] == '\0')))
  {
    strncpy(dest, file, dlen);
    return dest;
  }
 
  const char *fmt = "%s/%s";
 
  if (dir[strlen(dir) - 1] == '/')
    fmt = "%s%s";
 
  snprintf(dest, dlen, fmt, dir, file);
  return dest;
}
 
char *mutt_path_dirname(const char *path)
{
  if (!path)
    return NULL;
 
  char buf[PATH_MAX] = { 0 };
  mutt_str_copy(buf, path, sizeof(buf));
  return mutt_str_dup(dirname(buf));
}
 
bool mutt_path_to_absolute(char *path, const char *reference)
{
  if (!path || !reference)
    return false;
 
  char abs_path[PATH_MAX] = { 0 };
  int path_len;
 
  /* if path is already absolute, don't do anything */
  if ((strlen(path) > 1) && (path[0] == '/'))
  {
    return true;
  }
 
  char *dirpath = mutt_path_dirname(reference);
  mutt_str_copy(abs_path, dirpath, sizeof(abs_path));
  FREE(&dirpath);
  mutt_strn_cat(abs_path, sizeof(abs_path), "/", 1); /* append a / at the end of the path */
 
  path_len = sizeof(abs_path) - strlen(path);
 
  mutt_strn_cat(abs_path, sizeof(abs_path), path, (path_len > 0) ? path_len : 0);
 
  path = realpath(abs_path, path);
  if (!path && (errno != ENOENT))
  {
    mutt_perror(_("Error: converting path to absolute"));
    return false;
  }
 
  return true;
}
 
size_t mutt_path_realpath(struct Buffer *path)
{
  if (buf_is_empty(path))
    return 0;
 
  char s[PATH_MAX] = { 0 };
 
  if (!realpath(buf_string(path), s))
    return 0;
 
  return buf_strcpy(path, s);
}
 
bool mutt_path_parent(struct Buffer *path)
{
  if (buf_is_empty(path))
    return false;
 
  int n = buf_len(path);
  if (n < 2)
    return false;
 
  if (buf_at(path, n - 1) == '/')
    n--;
 
  // Find the previous '/'
  for (n--; ((n >= 0) && (buf_at(path, n) != '/')); n--)
    ; // do nothing
 
  if (n == 0) // Always keep at least one '/'
    n++;
 
  path->data[n] = '\0';
  buf_fix_dptr(path);
  return true;
}
 
bool mutt_path_abbr_folder(struct Buffer *path, const char *folder)
{
  if (buf_is_empty(path) || !folder)
    return false;
 
  size_t flen = mutt_str_len(folder);
  if (flen < 2)
    return false;
 
  if (folder[flen - 1] == '/')
    flen--;
 
  if (!mutt_strn_equal(buf_string(path), folder, flen))
    return false;
 
  if (buf_at(path, flen + 1) == '\0') // Don't abbreviate to '=/'
    return false;
 
  size_t rlen = mutt_str_len(path->data + flen + 1);
 
  path->data[0] = '=';
  memmove(path->data + 1, path->data + flen + 1, rlen + 1);
  buf_fix_dptr(path);
 
  return true;
}
 
char *mutt_path_escape(const char *src)
{
  if (!src)
    return NULL;
 
  static char dest[STR_COMMAND];
  char *destp = dest;
  int destsize = 0;
 
  while (*src && (destsize < sizeof(dest) - 1))
  {
    if (*src != '\'')
    {
      *destp++ = *src++;
      destsize++;
    }
    else
    {
      /* convert ' into '\'' */
      if ((destsize + 4) < sizeof(dest))
      {
        *destp++ = *src++;
        *destp++ = '\\';
        *destp++ = '\'';
        *destp++ = '\'';
        destsize += 4;
      }
      else
      {
        break; // LCOV_EXCL_LINE
      }
    }
  }
  *destp = '\0';
 
  return dest;
}
 
const char *mutt_path_getcwd(struct Buffer *cwd)
{
  if (!cwd)
    return NULL;
 
  buf_alloc(cwd, PATH_MAX);
  char *rc = getcwd(cwd->data, cwd->dsize);
  while (!rc && (errno == ERANGE))
  {
    buf_alloc(cwd, cwd->dsize + 256);   // LCOV_EXCL_LINE
    rc = getcwd(cwd->data, cwd->dsize); // LCOV_EXCL_LINE
  }
  if (rc)
    buf_fix_dptr(cwd);
  else
    buf_reset(cwd); // LCOV_EXCL_LINE
 
  return rc;
}