/src/gettext-0.26/gettext-tools/src/format-sh.c

Source
/* Shell format strings.
   Copyright (C) 2003-2025 Free Software Foundation, Inc.
   Written by Bruno Haible <bruno@clisp.org>, 2003.

   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 <https://www.gnu.org/licenses/>.  */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include <stdbool.h>
#include <stdlib.h>
#include <string.h>

#include "format.h"
#include "c-ctype.h"
#include "xalloc.h"
#include "format-invalid.h"
#include "gettext.h"

#define _(str) gettext (str)

/* Shell format strings are simply strings subjects to variable substitution.
   A variable substitution starts with '$' and is finished by either
   - a nonempty sequence of alphanumeric ASCII characters, the first being
     not a digit, or
   - an opening brace '{', a nonempty sequence of alphanumeric ASCII
     characters, the first being not a digit, and a closing brace '}'.
   We don't support variable references like $1, $$ or $? since they make
   no sense when 'envsubst' is invoked.
   We don't support non-ASCII variable names, to avoid dependencies w.r.t. the
   current encoding: While "${\xe0}" looks like a variable access in ISO-8859-1
   encoding, it doesn't look like one in the BIG5, BIG5-HKSCS, GBK, GB18030,
   SHIFT_JIS, JOHAB encodings, because \xe0\x7d is a single character in these
   encodings.
   We don't support the POSIX syntax for default or alternate values:
     ${variable-default}        ${variable:-default}
     ${variable=default}        ${variable:=default}
     ${variable+replacement}    ${variable:+replacement}
     ${variable?ignored}        ${variable:?ignored}
   because the translator might be tempted to change the default value; if
   we allow it we have a security problem; if we don't allow it the translator
   will be surprised.
 */

struct named_arg
{
  char *name;
};

struct spec
{
  size_t directives;
  size_t named_arg_count;
  struct named_arg *named;
};


static int
named_arg_compare (const void *p1, const void *p2)
{
  return strcmp (((const struct named_arg *) p1)->name,
                 ((const struct named_arg *) p2)->name);
}

#define INVALID_NON_ASCII_VARIABLE() \
  xstrdup (_("The string refers to a shell variable with a non-ASCII name."))
#define INVALID_SHELL_SYNTAX() \
  xstrdup (_("The string refers to a shell variable with complex shell brace syntax. This syntax is unsupported here due to security reasons."))
#define INVALID_CONTEXT_DEPENDENT_VARIABLE() \
  xstrdup (_("The string refers to a shell variable whose value may be different inside shell functions."))
#define INVALID_EMPTY_VARIABLE() \
  xstrdup (_("The string refers to a shell variable with an empty name."))

static void *
format_parse (const char *format, bool translated, char *fdi,
              char **invalid_reason)
{
  const char *const format_start = format;
  struct spec spec;
  size_t named_allocated;
  struct spec *result;

  spec.directives = 0;
  spec.named_arg_count = 0;
  spec.named = NULL;
  named_allocated = 0;

  for (; *format != '\0';)
    if (*format++ == '$')
      {
        /* A variable substitution.  */
        char *name;

        FDI_SET (format - 1, FMTDIR_START);
        spec.directives++;

        if (*format == '{')
          {
            const char *name_start;
            const char *name_end;
            size_t n;

            name_start = ++format;
            for (; *format != '\0'; format++)
              {
                if (*format == '}')
                  break;
                if (!c_isascii (*format))
                  {
                    *invalid_reason = INVALID_NON_ASCII_VARIABLE ();
                    FDI_SET (format, FMTDIR_ERROR);
                    goto bad_format;
                  }
                if (format > name_start
                    && (*format == '-' || *format == '=' || *format == '+'
                        || *format == '?' || *format == ':'))
                  {
                    *invalid_reason = INVALID_SHELL_SYNTAX ();
                    FDI_SET (format, FMTDIR_ERROR);
                    goto bad_format;
                  }
                if (!(c_isalnum (*format) || *format == '_')
                    || (format == name_start && c_isdigit (*format)))
                  {
                    *invalid_reason = INVALID_CONTEXT_DEPENDENT_VARIABLE ();
                    FDI_SET (format, FMTDIR_ERROR);
                    goto bad_format;
                  }
              }
            if (*format == '\0')
              {
                *invalid_reason = INVALID_UNTERMINATED_DIRECTIVE ();
                FDI_SET (format - 1, FMTDIR_ERROR);
                goto bad_format;
              }
            name_end = format++;

            n = name_end - name_start;
            if (n == 0)
              {
                *invalid_reason = INVALID_EMPTY_VARIABLE ();
                FDI_SET (format - 1, FMTDIR_ERROR);
                goto bad_format;
              }
            name = XNMALLOC (n + 1, char);
            memcpy (name, name_start, n);
            name[n] = '\0';
          }
        else if (c_isalpha (*format) || *format == '_')
          {
            const char *name_start;
            const char *name_end;
            size_t n;

            name_start = format;
            do
              format++;
            while (*format != '\0' && (c_isalnum (*format) || *format == '_'));
            name_end = format;

            n = name_end - name_start;
            name = XNMALLOC (n + 1, char);
            memcpy (name, name_start, n);
            name[n] = '\0';
          }
        else if (*format != '\0')
          {
            if (!c_isascii (*format))
              {
                *invalid_reason = INVALID_NON_ASCII_VARIABLE ();
                FDI_SET (format, FMTDIR_ERROR);
                goto bad_format;
              }
            else
              {
                *invalid_reason = INVALID_CONTEXT_DEPENDENT_VARIABLE ();
                FDI_SET (format, FMTDIR_ERROR);
                goto bad_format;
              }
          }
        else
          {
            *invalid_reason = INVALID_UNTERMINATED_DIRECTIVE ();
            FDI_SET (format - 1, FMTDIR_ERROR);
            goto bad_format;
          }

        /* Named argument.  */
        if (named_allocated == spec.named_arg_count)
          {
            named_allocated = 2 * named_allocated + 1;
            spec.named = (struct named_arg *) xrealloc (spec.named, named_allocated * sizeof (struct named_arg));
          }
        spec.named[spec.named_arg_count].name = name;
        spec.named_arg_count++;

        FDI_SET (format - 1, FMTDIR_END);
      }

  /* Sort the named argument array, and eliminate duplicates.  */
  if (spec.named_arg_count > 1)
    {
      size_t i, j;

      qsort (spec.named, spec.named_arg_count, sizeof (struct named_arg),
             named_arg_compare);

      /* Remove duplicates: Copy from i to j, keeping 0 <= j <= i.  */
      for (i = j = 0; i < spec.named_arg_count; i++)
        if (j > 0 && strcmp (spec.named[i].name, spec.named[j-1].name) == 0)
          free (spec.named[i].name);
        else
          {
            if (j < i)
              spec.named[j].name = spec.named[i].name;
            j++;
          }
      spec.named_arg_count = j;
    }

  result = XMALLOC (struct spec);
  *result = spec;
  return result;

 bad_format:
  if (spec.named != NULL)
    {
      size_t i;
      for (i = 0; i < spec.named_arg_count; i++)
        free (spec.named[i].name);
      free (spec.named);
    }
  return NULL;
}

static void
format_free (void *descr)
{
  struct spec *spec = (struct spec *) descr;

  if (spec->named != NULL)
    {
      size_t i;
      for (i = 0; i < spec->named_arg_count; i++)
        free (spec->named[i].name);
      free (spec->named);
    }
  free (spec);
}

static int
format_get_number_of_directives (void *descr)
{
  struct spec *spec = (struct spec *) descr;

  return spec->directives;
}

static bool
format_check (void *msgid_descr, void *msgstr_descr, bool equality,
              formatstring_error_logger_t error_logger, void *error_logger_data,
              const char *pretty_msgid, const char *pretty_msgstr)
{
  struct spec *spec1 = (struct spec *) msgid_descr;
  struct spec *spec2 = (struct spec *) msgstr_descr;
  bool err = false;

  if (spec1->named_arg_count + spec2->named_arg_count > 0)
    {
      size_t i, j;
      size_t n1 = spec1->named_arg_count;
      size_t n2 = spec2->named_arg_count;

      /* Check the argument names in spec2 are contained in those of spec1.
         Both arrays are sorted.  We search for the first difference.  */
      for (i = 0, j = 0; i < n1 || j < n2; )
        {
          int cmp = (i >= n1 ? 1 :
                     j >= n2 ? -1 :
                     strcmp (spec1->named[i].name, spec2->named[j].name));

          if (cmp > 0)
            {
              if (error_logger)
                error_logger (error_logger_data,
                              _("a format specification for argument '%s', as in '%s', doesn't exist in '%s'"),
                              spec2->named[j].name, pretty_msgstr,
                              pretty_msgid);
              err = true;
              break;
            }
          else if (cmp < 0)
            {
              if (equality)
                {
                  if (error_logger)
                    error_logger (error_logger_data,
                                  _("a format specification for argument '%s' doesn't exist in '%s'"),
                                  spec1->named[i].name, pretty_msgstr);
                  err = true;
                  break;
                }
              else
                i++;
            }
          else
            j++, i++;
        }
    }

  return err;
}


struct formatstring_parser formatstring_sh =
{
  format_parse,
  format_free,
  format_get_number_of_directives,
  NULL,
  format_check
};


#ifdef TEST

/* Test program: Print the argument list specification returned by
   format_parse for strings read from standard input.  */

#include <stdio.h>

static void
format_print (void *descr)
{
  struct spec *spec = (struct spec *) descr;
  size_t i;

  if (spec == NULL)
    {
      printf ("INVALID");
      return;
    }

  printf ("{");
  for (i = 0; i < spec->named_arg_count; i++)
    {
      if (i > 0)
        printf (", ");
      printf ("'%s'", spec->named[i].name);
    }
  printf ("}");
}

int
main ()
{
  for (;;)
    {
      char *line = NULL;
      size_t line_size = 0;
      int line_len;
      char *invalid_reason;
      void *descr;

      line_len = getline (&line, &line_size, stdin);
      if (line_len < 0)
        break;
      if (line_len > 0 && line[line_len - 1] == '\n')
        line[--line_len] = '\0';

      invalid_reason = NULL;
      descr = format_parse (line, false, NULL, &invalid_reason);

      format_print (descr);
      printf ("\n");
      if (descr == NULL)
        printf ("%s\n", invalid_reason);

      free (invalid_reason);
      free (line);
    }

  return 0;
}

/*
 * For Emacs M-x compile
 * Local Variables:
 * compile-command: "/bin/sh ../libtool --tag=CC --mode=link gcc -o a.out -static -O -g -Wall -I.. -I../gnulib-lib -I../../gettext-runtime/intl -DHAVE_CONFIG_H -DTEST format-sh.c ../gnulib-lib/libgettextlib.la"
 * End:
 */

#endif /* TEST */

Coverage Report

Created: 2026-01-25 07:18

Line	Count	Source
1		/* Shell format strings.
2		Copyright (C) 2003-2025 Free Software Foundation, Inc.
3		Written by Bruno Haible <bruno@clisp.org>, 2003.
4
5		This program is free software: you can redistribute it and/or modify
6		it under the terms of the GNU General Public License as published by
7		the Free Software Foundation; either version 3 of the License, or
8		(at your option) any later version.
9
10		This program is distributed in the hope that it will be useful,
11		but WITHOUT ANY WARRANTY; without even the implied warranty of
12		MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13		GNU General Public License for more details.
14
15		You should have received a copy of the GNU General Public License
16		along with this program. If not, see <https://www.gnu.org/licenses/>. */
17
18		#ifdef HAVE_CONFIG_H
19		# include <config.h>
20		#endif
21
22		#include <stdbool.h>
23		#include <stdlib.h>
24		#include <string.h>
25
26		#include "format.h"
27		#include "c-ctype.h"
28		#include "xalloc.h"
29		#include "format-invalid.h"
30		#include "gettext.h"
31
32	0	#define _(str) gettext (str)
33
34		/* Shell format strings are simply strings subjects to variable substitution.
35		A variable substitution starts with '$' and is finished by either
36		- a nonempty sequence of alphanumeric ASCII characters, the first being
37		not a digit, or
38		- an opening brace '{', a nonempty sequence of alphanumeric ASCII
39		characters, the first being not a digit, and a closing brace '}'.
40		We don't support variable references like $1, $$ or $? since they make
41		no sense when 'envsubst' is invoked.
42		We don't support non-ASCII variable names, to avoid dependencies w.r.t. the
43		current encoding: While "${\xe0}" looks like a variable access in ISO-8859-1
44		encoding, it doesn't look like one in the BIG5, BIG5-HKSCS, GBK, GB18030,
45		SHIFT_JIS, JOHAB encodings, because \xe0\x7d is a single character in these
46		encodings.
47		We don't support the POSIX syntax for default or alternate values:
48		${variable-default} ${variable:-default}
49		${variable=default} ${variable:=default}
50		${variable+replacement} ${variable:+replacement}
51		${variable?ignored} ${variable:?ignored}
52		because the translator might be tempted to change the default value; if
53		we allow it we have a security problem; if we don't allow it the translator
54		will be surprised.
55		*/
56
57		struct named_arg
58		{
59		char *name;
60		};
61
62		struct spec
63		{
64		size_t directives;
65		size_t named_arg_count;
66		struct named_arg *named;
67		};
68
69
70		static int
71		named_arg_compare (const void p1, const void p2)
72	0	{
73	0	return strcmp (((const struct named_arg *) p1)->name,
74	0	((const struct named_arg *) p2)->name);
75	0	}
76
77		#define INVALID_NON_ASCII_VARIABLE() \
78	0	xstrdup (_("The string refers to a shell variable with a non-ASCII name."))
79		#define INVALID_SHELL_SYNTAX() \
80	0	xstrdup (_("The string refers to a shell variable with complex shell brace syntax. This syntax is unsupported here due to security reasons."))
81		#define INVALID_CONTEXT_DEPENDENT_VARIABLE() \
82	0	xstrdup (_("The string refers to a shell variable whose value may be different inside shell functions."))
83		#define INVALID_EMPTY_VARIABLE() \
84	0	xstrdup (_("The string refers to a shell variable with an empty name."))
85
86		static void *
87		format_parse (const char format, bool translated, char fdi,
88		char **invalid_reason)
89	0	{
90	0	const char *const format_start = format;
91	0	struct spec spec;
92	0	size_t named_allocated;
93	0	struct spec *result;
94
95	0	spec.directives = 0;
96	0	spec.named_arg_count = 0;
97	0	spec.named = NULL;
98	0	named_allocated = 0;
99
100	0	for (; *format != '\0';)
101	0	if (*format++ == '$')
102	0	{
103		/* A variable substitution. */
104	0	char *name;
105
106	0	FDI_SET (format - 1, FMTDIR_START);
107	0	spec.directives++;
108
109	0	if (*format == '{')
110	0	{
111	0	const char *name_start;
112	0	const char *name_end;
113	0	size_t n;
114
115	0	name_start = ++format;
116	0	for (; *format != '\0'; format++)
117	0	{
118	0	if (*format == '}')
119	0	break;
120	0	if (!c_isascii (*format))
121	0	{
122	0	*invalid_reason = INVALID_NON_ASCII_VARIABLE ();
123	0	FDI_SET (format, FMTDIR_ERROR);
124	0	goto bad_format;
125	0	}
126	0	if (format > name_start
127	0	&& (format == '-' \|\| format == '=' \|\| *format == '+'
128	0	\|\| format == '?' \|\| format == ':'))
129	0	{
130	0	*invalid_reason = INVALID_SHELL_SYNTAX ();
131	0	FDI_SET (format, FMTDIR_ERROR);
132	0	goto bad_format;
133	0	}
134	0	if (!(c_isalnum (format) \|\| format == '_')
135	0	\|\| (format == name_start && c_isdigit (*format)))
136	0	{
137	0	*invalid_reason = INVALID_CONTEXT_DEPENDENT_VARIABLE ();
138	0	FDI_SET (format, FMTDIR_ERROR);
139	0	goto bad_format;
140	0	}
141	0	}
142	0	if (*format == '\0')
143	0	{
144	0	*invalid_reason = INVALID_UNTERMINATED_DIRECTIVE ();
145	0	FDI_SET (format - 1, FMTDIR_ERROR);
146	0	goto bad_format;
147	0	}
148	0	name_end = format++;
149
150	0	n = name_end - name_start;
151	0	if (n == 0)
152	0	{
153	0	*invalid_reason = INVALID_EMPTY_VARIABLE ();
154	0	FDI_SET (format - 1, FMTDIR_ERROR);
155	0	goto bad_format;
156	0	}
157	0	name = XNMALLOC (n + 1, char);
158	0	memcpy (name, name_start, n);
159	0	name[n] = '\0';
160	0	}
161	0	else if (c_isalpha (format) \|\| format == '_')
162	0	{
163	0	const char *name_start;
164	0	const char *name_end;
165	0	size_t n;
166
167	0	name_start = format;
168	0	do
169	0	format++;
170	0	while (format != '\0' && (c_isalnum (format) \|\| *format == '_'));
171	0	name_end = format;
172
173	0	n = name_end - name_start;
174	0	name = XNMALLOC (n + 1, char);
175	0	memcpy (name, name_start, n);
176	0	name[n] = '\0';
177	0	}
178	0	else if (*format != '\0')
179	0	{
180	0	if (!c_isascii (*format))
181	0	{
182	0	*invalid_reason = INVALID_NON_ASCII_VARIABLE ();
183	0	FDI_SET (format, FMTDIR_ERROR);
184	0	goto bad_format;
185	0	}
186	0	else
187	0	{
188	0	*invalid_reason = INVALID_CONTEXT_DEPENDENT_VARIABLE ();
189	0	FDI_SET (format, FMTDIR_ERROR);
190	0	goto bad_format;
191	0	}
192	0	}
193	0	else
194	0	{
195	0	*invalid_reason = INVALID_UNTERMINATED_DIRECTIVE ();
196	0	FDI_SET (format - 1, FMTDIR_ERROR);
197	0	goto bad_format;
198	0	}
199
200		/* Named argument. */
201	0	if (named_allocated == spec.named_arg_count)
202	0	{
203	0	named_allocated = 2 * named_allocated + 1;
204	0	spec.named = (struct named_arg ) xrealloc (spec.named, named_allocated sizeof (struct named_arg));
205	0	}
206	0	spec.named[spec.named_arg_count].name = name;
207	0	spec.named_arg_count++;
208
209	0	FDI_SET (format - 1, FMTDIR_END);
210	0	}
211
212		/* Sort the named argument array, and eliminate duplicates. */
213	0	if (spec.named_arg_count > 1)
214	0	{
215	0	size_t i, j;
216
217	0	qsort (spec.named, spec.named_arg_count, sizeof (struct named_arg),
218	0	named_arg_compare);
219
220		/* Remove duplicates: Copy from i to j, keeping 0 <= j <= i. */
221	0	for (i = j = 0; i < spec.named_arg_count; i++)
222	0	if (j > 0 && strcmp (spec.named[i].name, spec.named[j-1].name) == 0)
223	0	free (spec.named[i].name);
224	0	else
225	0	{
226	0	if (j < i)
227	0	spec.named[j].name = spec.named[i].name;
228	0	j++;
229	0	}
230	0	spec.named_arg_count = j;
231	0	}
232
233	0	result = XMALLOC (struct spec);
234	0	*result = spec;
235	0	return result;
236
237	0	bad_format:
238	0	if (spec.named != NULL)
239	0	{
240	0	size_t i;
241	0	for (i = 0; i < spec.named_arg_count; i++)
242	0	free (spec.named[i].name);
243	0	free (spec.named);
244	0	}
245	0	return NULL;
246	0	}
247
248		static void
249		format_free (void *descr)
250	0	{
251	0	struct spec spec = (struct spec ) descr;
252
253	0	if (spec->named != NULL)
254	0	{
255	0	size_t i;
256	0	for (i = 0; i < spec->named_arg_count; i++)
257	0	free (spec->named[i].name);
258	0	free (spec->named);
259	0	}
260	0	free (spec);
261	0	}
262
263		static int
264		format_get_number_of_directives (void *descr)
265	0	{
266	0	struct spec spec = (struct spec ) descr;
267
268	0	return spec->directives;
269	0	}
270
271		static bool
272		format_check (void msgid_descr, void msgstr_descr, bool equality,
273		formatstring_error_logger_t error_logger, void *error_logger_data,
274		const char pretty_msgid, const char pretty_msgstr)
275	0	{
276	0	struct spec spec1 = (struct spec ) msgid_descr;
277	0	struct spec spec2 = (struct spec ) msgstr_descr;
278	0	bool err = false;
279
280	0	if (spec1->named_arg_count + spec2->named_arg_count > 0)
281	0	{
282	0	size_t i, j;
283	0	size_t n1 = spec1->named_arg_count;
284	0	size_t n2 = spec2->named_arg_count;
285
286		/* Check the argument names in spec2 are contained in those of spec1.
287		Both arrays are sorted. We search for the first difference. */
288	0	for (i = 0, j = 0; i < n1 \|\| j < n2; )
289	0	{
290	0	int cmp = (i >= n1 ? 1 :
291	0	j >= n2 ? -1 :
292	0	strcmp (spec1->named[i].name, spec2->named[j].name));
293
294	0	if (cmp > 0)
295	0	{
296	0	if (error_logger)
297	0	error_logger (error_logger_data,
298	0	_("a format specification for argument '%s', as in '%s', doesn't exist in '%s'"),
299	0	spec2->named[j].name, pretty_msgstr,
300	0	pretty_msgid);
301	0	err = true;
302	0	break;
303	0	}
304	0	else if (cmp < 0)
305	0	{
306	0	if (equality)
307	0	{
308	0	if (error_logger)
309	0	error_logger (error_logger_data,
310	0	_("a format specification for argument '%s' doesn't exist in '%s'"),
311	0	spec1->named[i].name, pretty_msgstr);
312	0	err = true;
313	0	break;
314	0	}
315	0	else
316	0	i++;
317	0	}
318	0	else
319	0	j++, i++;
320	0	}
321	0	}
322
323	0	return err;
324	0	}
325
326
327		struct formatstring_parser formatstring_sh =
328		{
329		format_parse,
330		format_free,
331		format_get_number_of_directives,
332		NULL,
333		format_check
334		};
335
336
337		#ifdef TEST
338
339		/* Test program: Print the argument list specification returned by
340		format_parse for strings read from standard input. */
341
342		#include <stdio.h>
343
344		static void
345		format_print (void *descr)
346		{
347		struct spec spec = (struct spec ) descr;
348		size_t i;
349
350		if (spec == NULL)
351		{
352		printf ("INVALID");
353		return;
354		}
355
356		printf ("{");
357		for (i = 0; i < spec->named_arg_count; i++)
358		{
359		if (i > 0)
360		printf (", ");
361		printf ("'%s'", spec->named[i].name);
362		}
363		printf ("}");
364		}
365
366		int
367		main ()
368		{
369		for (;;)
370		{
371		char *line = NULL;
372		size_t line_size = 0;
373		int line_len;
374		char *invalid_reason;
375		void *descr;
376
377		line_len = getline (&line, &line_size, stdin);
378		if (line_len < 0)
379		break;
380		if (line_len > 0 && line[line_len - 1] == '\n')
381		line[--line_len] = '\0';
382
383		invalid_reason = NULL;
384		descr = format_parse (line, false, NULL, &invalid_reason);
385
386		format_print (descr);
387		printf ("\n");
388		if (descr == NULL)
389		printf ("%s\n", invalid_reason);
390
391		free (invalid_reason);
392		free (line);
393		}
394
395		return 0;
396		}
397
398		/*
399		* For Emacs M-x compile
400		* Local Variables:
401		* compile-command: "/bin/sh ../libtool --tag=CC --mode=link gcc -o a.out -static -O -g -Wall -I.. -I../gnulib-lib -I../../gettext-runtime/intl -DHAVE_CONFIG_H -DTEST format-sh.c ../gnulib-lib/libgettextlib.la"
402		* End:
403		*/
404
405		#endif /* TEST */