[thirdparty/git.git] / sh-i18n--envsubst.c

/*
 * sh-i18n--envsubst.c - a stripped-down version of gettext's envsubst(1)
 *
 * Copyright (C) 2010 Ævar Arnfjörð Bjarmason
 *
 * This is a modified version of
 * 67d0871a8c:gettext-runtime/src/envsubst.c from the gettext.git
 * repository. It has been stripped down to only implement the
 * envsubst(1) features that we need in the git-sh-i18n fallbacks.
 *
 * The "Close standard error" part in main() is from
 * 8dac033df0:gnulib-local/lib/closeout.c. The copyright notices for
 * both files are reproduced immediately below.
 */

#include "git-compat-util.h"

/* Substitution of environment variables in shell format strings.
   Copyright (C) 2003-2007 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 2, 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/>.  */

/* closeout.c - close standard output and standard error
   Copyright (C) 1998-2007 Free Software Foundation, Inc.

   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, 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 <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/* If true, substitution shall be performed on all variables.  */
static unsigned short int all_variables;

/* Forward declaration of local functions.  */
static void print_variables (const char *string);
static void note_variables (const char *string);
static void subst_from_stdin (void);

int
cmd_main (int argc, const char *argv[])
{
  /* Default values for command line options.  */
  /* unsigned short int show_variables = 0; */

  switch (argc)
	{
	case 1:
	  error ("we won't substitute all variables on stdin for you");
	  break;
	  /*
	  all_variables = 1;
      subst_from_stdin ();
	  */
	case 2:
	  /* echo '$foo and $bar' | git sh-i18n--envsubst --variables '$foo and $bar' */
	  all_variables = 0;
	  note_variables (argv[1]);
      subst_from_stdin ();
	  break;
	case 3:
	  /* git sh-i18n--envsubst --variables '$foo and $bar' */
	  if (strcmp(argv[1], "--variables"))
		error ("first argument must be --variables when two are given");
	  /* show_variables = 1; */
      print_variables (argv[2]);
	  break;
	default:
	  error ("too many arguments");
	  break;
	}

  /* Close standard error.  This is simpler than fwriteerror_no_ebadf, because
     upon failure we don't need an errno - all we can do at this point is to
     set an exit status.  */
  errno = 0;
  if (ferror (stderr) || fflush (stderr))
    {
      fclose (stderr);
      exit (EXIT_FAILURE);
    }
  if (fclose (stderr) && errno != EBADF)
    exit (EXIT_FAILURE);

  exit (EXIT_SUCCESS);
}

/* Parse the string and invoke the callback each time a $VARIABLE or
   ${VARIABLE} construct is seen, where VARIABLE is a nonempty sequence
   of ASCII alphanumeric/underscore characters, starting with an ASCII
   alphabetic/underscore character.
   We allow only ASCII characters, to avoid dependencies w.r.t. the current
   encoding: While "${\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.  */
static void
find_variables (const char *string,
		void (*callback) (const char *var_ptr, size_t var_len))
{
  for (; *string != '\0';)
    if (*string++ == '$')
      {
	const char *variable_start;
	const char *variable_end;
	unsigned short int valid;
	char c;

	if (*string == '{')
	  string++;

	variable_start = string;
	c = *string;
	if ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || c == '_')
	  {
	    do
	      c = *++string;
	    while ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z')
		   || (c >= '0' && c <= '9') || c == '_');
	    variable_end = string;

	    if (variable_start[-1] == '{')
	      {
		if (*string == '}')
		  {
		    string++;
		    valid = 1;
		  }
		else
		  valid = 0;
	      }
	    else
	      valid = 1;

	    if (valid)
	      callback (variable_start, variable_end - variable_start);
	  }
      }
}


/* Print a variable to stdout, followed by a newline.  */
static void
print_variable (const char *var_ptr, size_t var_len)
{
  fwrite (var_ptr, var_len, 1, stdout);
  putchar ('\n');
}

/* Print the variables contained in STRING to stdout, each one followed by a
   newline.  */
static void
print_variables (const char *string)
{
  find_variables (string, &print_variable);
}


/* Type describing list of immutable strings,
   implemented using a dynamic array.  */
typedef struct string_list_ty string_list_ty;
struct string_list_ty
{
  const char **item;
  size_t nitems;
  size_t nitems_max;
};

/* Initialize an empty list of strings.  */
static inline void
string_list_init (string_list_ty *slp)
{
  slp->item = NULL;
  slp->nitems = 0;
  slp->nitems_max = 0;
}

/* Append a single string to the end of a list of strings.  */
static inline void
string_list_append (string_list_ty *slp, const char *s)
{
  /* Grow the list.  */
  if (slp->nitems >= slp->nitems_max)
    {
      slp->nitems_max = slp->nitems_max * 2 + 4;
      REALLOC_ARRAY(slp->item, slp->nitems_max);
    }

  /* Add the string to the end of the list.  */
  slp->item[slp->nitems++] = s;
}

/* Compare two strings given by reference.  */
static int
cmp_string (const void *pstr1, const void *pstr2)
{
  const char *str1 = *(const char **)pstr1;
  const char *str2 = *(const char **)pstr2;

  return strcmp (str1, str2);
}

/* Sort a list of strings.  */
static inline void
string_list_sort (string_list_ty *slp)
{
  QSORT(slp->item, slp->nitems, cmp_string);
}

/* Test whether a sorted string list contains a given string.  */
static int
sorted_string_list_member (const string_list_ty *slp, const char *s)
{
  size_t j1, j2;

  j1 = 0;
  j2 = slp->nitems;
  if (j2 > 0)
    {
      /* Binary search.  */
      while (j2 - j1 > 1)
	{
	  /* Here we know that if s is in the list, it is at an index j
	     with j1 <= j < j2.  */
	  size_t j = (j1 + j2) >> 1;
	  int result = strcmp (slp->item[j], s);

	  if (result > 0)
	    j2 = j;
	  else if (result == 0)
	    return 1;
	  else
	    j1 = j + 1;
	}
      if (j2 > j1)
	if (strcmp (slp->item[j1], s) == 0)
	  return 1;
    }
  return 0;
}


/* Set of variables on which to perform substitution.
   Used only if !all_variables.  */
static string_list_ty variables_set;

/* Adds a variable to variables_set.  */
static void
note_variable (const char *var_ptr, size_t var_len)
{
  char *string = xmemdupz (var_ptr, var_len);

  string_list_append (&variables_set, string);
}

/* Stores the variables occurring in the string in variables_set.  */
static void
note_variables (const char *string)
{
  string_list_init (&variables_set);
  find_variables (string, &note_variable);
  string_list_sort (&variables_set);
}


static int
do_getc (void)
{
  int c = getc (stdin);

  if (c == EOF)
    {
      if (ferror (stdin))
	error ("error while reading standard input");
    }

  return c;
}

static inline void
do_ungetc (int c)
{
  if (c != EOF)
    ungetc (c, stdin);
}

/* Copies stdin to stdout, performing substitutions.  */
static void
subst_from_stdin (void)
{
  static char *buffer;
  static size_t bufmax;
  static size_t buflen;
  int c;

  for (;;)
    {
      c = do_getc ();
      if (c == EOF)
	break;
      /* Look for $VARIABLE or ${VARIABLE}.  */
      if (c == '$')
	{
	  unsigned short int opening_brace = 0;
	  unsigned short int closing_brace = 0;

	  c = do_getc ();
	  if (c == '{')
	    {
	      opening_brace = 1;
	      c = do_getc ();
	    }
	  if ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || c == '_')
	    {
	      unsigned short int valid;

	      /* Accumulate the VARIABLE in buffer.  */
	      buflen = 0;
	      do
		{
		  if (buflen >= bufmax)
		    {
		      bufmax = 2 * bufmax + 10;
		      buffer = xrealloc (buffer, bufmax);
		    }
		  buffer[buflen++] = c;

		  c = do_getc ();
		}
	      while ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z')
		     || (c >= '0' && c <= '9') || c == '_');

	      if (opening_brace)
		{
		  if (c == '}')
		    {
		      closing_brace = 1;
		      valid = 1;
		    }
		  else
		    {
		      valid = 0;
		      do_ungetc (c);
		    }
		}
	      else
		{
		  valid = 1;
		  do_ungetc (c);
		}

	      if (valid)
		{
		  /* Terminate the variable in the buffer.  */
		  if (buflen >= bufmax)
		    {
		      bufmax = 2 * bufmax + 10;
		      buffer = xrealloc (buffer, bufmax);
		    }
		  buffer[buflen] = '\0';

		  /* Test whether the variable shall be substituted.  */
		  if (!all_variables
		      && !sorted_string_list_member (&variables_set, buffer))
		    valid = 0;
		}

	      if (valid)
		{
		  /* Substitute the variable's value from the environment.  */
		  const char *env_value = getenv (buffer);

		  if (env_value != NULL)
		    fputs (env_value, stdout);
		}
	      else
		{
		  /* Perform no substitution at all.  Since the buffered input
		     contains no other '$' than at the start, we can just
		     output all the buffered contents.  */
		  putchar ('$');
		  if (opening_brace)
		    putchar ('{');
		  fwrite (buffer, buflen, 1, stdout);
		  if (closing_brace)
		    putchar ('}');
		}
	    }
	  else
	    {
	      do_ungetc (c);
	      putchar ('$');
	      if (opening_brace)
		putchar ('{');
	    }
	}
      else
	putchar (c);
    }
}
Commit	Line	Data
ba67aaf2 ÆAB	1	/*
	2	* sh-i18n--envsubst.c - a stripped-down version of gettext's envsubst(1)
	3	*
	4	* Copyright (C) 2010 Ævar Arnfjörð Bjarmason
	5	*
	6	* This is a modified version of
	7	* 67d0871a8c:gettext-runtime/src/envsubst.c from the gettext.git
	8	* repository. It has been stripped down to only implement the
	9	* envsubst(1) features that we need in the git-sh-i18n fallbacks.
	10	*
	11	* The "Close standard error" part in main() is from
	12	* 8dac033df0:gnulib-local/lib/closeout.c. The copyright notices for
	13	* both files are reproduced immediately below.
	14	*/
	15
	16	#include "git-compat-util.h"
	17
	18	/* Substitution of environment variables in shell format strings.
	19	Copyright (C) 2003-2007 Free Software Foundation, Inc.
	20	Written by Bruno Haible <bruno@clisp.org>, 2003.
	21
	22	This program is free software; you can redistribute it and/or modify
	23	it under the terms of the GNU General Public License as published by
	24	the Free Software Foundation; either version 2, or (at your option)
	25	any later version.
	26
	27	This program is distributed in the hope that it will be useful,
	28	but WITHOUT ANY WARRANTY; without even the implied warranty of
	29	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	30	GNU General Public License for more details.
	31
	32	You should have received a copy of the GNU General Public License
48425792	33	along with this program; if not, see <http://www.gnu.org/licenses/>. */
ba67aaf2 ÆAB	34
	35	/* closeout.c - close standard output and standard error
	36	Copyright (C) 1998-2007 Free Software Foundation, Inc.
	37
	38	This program is free software; you can redistribute it and/or modify
	39	it under the terms of the GNU General Public License as published by
	40	the Free Software Foundation; either version 2, or (at your option)
	41	any later version.
	42
	43	This program is distributed in the hope that it will be useful,
	44	but WITHOUT ANY WARRANTY; without even the implied warranty of
	45	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	46	GNU General Public License for more details.
	47
	48	You should have received a copy of the GNU General Public License
48425792	49	along with this program; if not, see <http://www.gnu.org/licenses/>. */
ba67aaf2 ÆAB	50
ba67aaf2 ÆAB	51	#include <errno.h>
ba67aaf2 ÆAB	52	#include <stdio.h>
	53	#include <stdlib.h>
	54	#include <string.h>
	55
	56	/* If true, substitution shall be performed on all variables. */
	57	static unsigned short int all_variables;
	58
	59	/* Forward declaration of local functions. */
	60	static void print_variables (const char *string);
	61	static void note_variables (const char *string);
	62	static void subst_from_stdin (void);
	63
	64	int
3f2e2297	65	cmd_main (int argc, const char *argv[])
ba67aaf2 ÆAB	66	{
ba67aaf2 ÆAB	67	/* Default values for command line options. */
600a6a68	68	/* unsigned short int show_variables = 0; */
ba67aaf2 ÆAB	69
	70	switch (argc)
	71	{
	72	case 1:
	73	error ("we won't substitute all variables on stdin for you");
8c92516f	74	break;
ba67aaf2 ÆAB	75	/*
	76	all_variables = 1;
	77	subst_from_stdin ();
	78	*/
	79	case 2:
	80	/* echo '$foo and $bar' \| git sh-i18n--envsubst --variables '$foo and $bar' */
	81	all_variables = 0;
	82	note_variables (argv[1]);
	83	subst_from_stdin ();
	84	break;
	85	case 3:
	86	/* git sh-i18n--envsubst --variables '$foo and $bar' */
	87	if (strcmp(argv[1], "--variables"))
	88	error ("first argument must be --variables when two are given");
600a6a68	89	/* show_variables = 1; */
ba67aaf2 ÆAB	90	print_variables (argv[2]);
	91	break;
	92	default:
	93	error ("too many arguments");
	94	break;
	95	}
	96
	97	/* Close standard error. This is simpler than fwriteerror_no_ebadf, because
	98	upon failure we don't need an errno - all we can do at this point is to
	99	set an exit status. */
	100	errno = 0;
	101	if (ferror (stderr) \|\| fflush (stderr))
	102	{
	103	fclose (stderr);
	104	exit (EXIT_FAILURE);
	105	}
	106	if (fclose (stderr) && errno != EBADF)
	107	exit (EXIT_FAILURE);
	108
	109	exit (EXIT_SUCCESS);
	110	}
	111
	112	/* Parse the string and invoke the callback each time a $VARIABLE or
	113	${VARIABLE} construct is seen, where VARIABLE is a nonempty sequence
	114	of ASCII alphanumeric/underscore characters, starting with an ASCII
	115	alphabetic/underscore character.
	116	We allow only ASCII characters, to avoid dependencies w.r.t. the current
	117	encoding: While "${\xe0}" looks like a variable access in ISO-8859-1
	118	encoding, it doesn't look like one in the BIG5, BIG5-HKSCS, GBK, GB18030,
	119	SHIFT_JIS, JOHAB encodings, because \xe0\x7d is a single character in these
	120	encodings. */
	121	static void
	122	find_variables (const char *string,
	123	void (callback) (const char var_ptr, size_t var_len))
	124	{
	125	for (; *string != '\0';)
	126	if (*string++ == '$')
	127	{
	128	const char *variable_start;
	129	const char *variable_end;
	130	unsigned short int valid;
	131	char c;
	132
	133	if (*string == '{')
	134	string++;
	135
	136	variable_start = string;
	137	c = *string;
	138	if ((c >= 'A' && c <= 'Z') \|\| (c >= 'a' && c <= 'z') \|\| c == '_')
	139	{
	140	do
	141	c = *++string;
	142	while ((c >= 'A' && c <= 'Z') \|\| (c >= 'a' && c <= 'z')
	143	\|\| (c >= '0' && c <= '9') \|\| c == '_');
	144	variable_end = string;
	145
	146	if (variable_start[-1] == '{')
	147	{
	148	if (*string == '}')
	149	{
	150	string++;
	151	valid = 1;
	152	}
	153	else
154	valid = 0;
155	}
156	else
157	valid = 1;
158
159	if (valid)
160	callback (variable_start, variable_end - variable_start);
161	}
162	}
163	}
164
165
166	/* Print a variable to stdout, followed by a newline. */
167	static void
168	print_variable (const char *var_ptr, size_t var_len)
169	{
170	fwrite (var_ptr, var_len, 1, stdout);
171	putchar ('\n');
172	}
173
174	/* Print the variables contained in STRING to stdout, each one followed by a
175	newline. */
176	static void
177	print_variables (const char *string)
178	{
179	find_variables (string, &print_variable);
180	}
181
182
183	/* Type describing list of immutable strings,
184	implemented using a dynamic array. */
185	typedef struct string_list_ty string_list_ty;
186	struct string_list_ty
187	{
188	const char **item;
189	size_t nitems;
190	size_t nitems_max;
191	};
192
193	/* Initialize an empty list of strings. */
194	static inline void
195	string_list_init (string_list_ty *slp)
196	{
197	slp->item = NULL;
198	slp->nitems = 0;
199	slp->nitems_max = 0;
200	}
201
202	/* Append a single string to the end of a list of strings. */
203	static inline void
204	string_list_append (string_list_ty slp, const char s)
205	{
206	/* Grow the list. */
207	if (slp->nitems >= slp->nitems_max)
208	{
ba67aaf2	209	slp->nitems_max = slp->nitems_max * 2 + 4;
2756ca43	210	REALLOC_ARRAY(slp->item, slp->nitems_max);
ba67aaf2 ÆAB	211	}
	212
	213	/* Add the string to the end of the list. */
	214	slp->item[slp->nitems++] = s;
	215	}
	216
	217	/* Compare two strings given by reference. */
	218	static int
	219	cmp_string (const void pstr1, const void pstr2)
	220	{
	221	const char str1 = (const char **)pstr1;
	222	const char str2 = (const char **)pstr2;
	223
	224	return strcmp (str1, str2);
	225	}
	226
	227	/* Sort a list of strings. */
	228	static inline void
	229	string_list_sort (string_list_ty *slp)
	230	{
76dd98c1	231	QSORT(slp->item, slp->nitems, cmp_string);
ba67aaf2 ÆAB	232	}
ba67aaf2 ÆAB	233
ba67aaf2 ÆAB	234	/* Test whether a sorted string list contains a given string. */
	235	static int
	236	sorted_string_list_member (const string_list_ty slp, const char s)
	237	{
	238	size_t j1, j2;
	239
	240	j1 = 0;
	241	j2 = slp->nitems;
	242	if (j2 > 0)
	243	{
	244	/* Binary search. */
	245	while (j2 - j1 > 1)
	246	{
	247	/* Here we know that if s is in the list, it is at an index j
	248	with j1 <= j < j2. */
	249	size_t j = (j1 + j2) >> 1;
	250	int result = strcmp (slp->item[j], s);
	251
	252	if (result > 0)
	253	j2 = j;
	254	else if (result == 0)
	255	return 1;
	256	else
	257	j1 = j + 1;
	258	}
	259	if (j2 > j1)
	260	if (strcmp (slp->item[j1], s) == 0)
	261	return 1;
	262	}
	263	return 0;
	264	}
	265
	266
	267	/* Set of variables on which to perform substitution.
	268	Used only if !all_variables. */
	269	static string_list_ty variables_set;
	270
	271	/* Adds a variable to variables_set. */
	272	static void
	273	note_variable (const char *var_ptr, size_t var_len)
	274	{
5c0b13f8	275	char *string = xmemdupz (var_ptr, var_len);
ba67aaf2 ÆAB	276
	277	string_list_append (&variables_set, string);
	278	}
	279
	280	/* Stores the variables occurring in the string in variables_set. */
	281	static void
	282	note_variables (const char *string)
	283	{
	284	string_list_init (&variables_set);
	285	find_variables (string, &note_variable);
	286	string_list_sort (&variables_set);
	287	}
	288
	289
	290	static int
	291	do_getc (void)
	292	{
	293	int c = getc (stdin);
	294
	295	if (c == EOF)
	296	{
	297	if (ferror (stdin))
	298	error ("error while reading standard input");
	299	}
	300
	301	return c;
	302	}
	303
	304	static inline void
	305	do_ungetc (int c)
	306	{
	307	if (c != EOF)
	308	ungetc (c, stdin);
	309	}
	310
	311	/* Copies stdin to stdout, performing substitutions. */
	312	static void
	313	subst_from_stdin (void)
	314	{
	315	static char *buffer;
	316	static size_t bufmax;
	317	static size_t buflen;
	318	int c;
	319
	320	for (;;)
	321	{
	322	c = do_getc ();
	323	if (c == EOF)
	324	break;
	325	/* Look for $VARIABLE or ${VARIABLE}. */
	326	if (c == '$')
	327	{
	328	unsigned short int opening_brace = 0;
	329	unsigned short int closing_brace = 0;
	330
	331	c = do_getc ();
	332	if (c == '{')
	333	{
	334	opening_brace = 1;
	335	c = do_getc ();
	336	}
	337	if ((c >= 'A' && c <= 'Z') \|\| (c >= 'a' && c <= 'z') \|\| c == '_')
	338	{
	339	unsigned short int valid;
340
341	/* Accumulate the VARIABLE in buffer. */
342	buflen = 0;
343	do
344	{
345	if (buflen >= bufmax)
346	{
347	bufmax = 2 * bufmax + 10;
348	buffer = xrealloc (buffer, bufmax);
349	}
350	buffer[buflen++] = c;
351
352	c = do_getc ();
353	}
354	while ((c >= 'A' && c <= 'Z') \|\| (c >= 'a' && c <= 'z')
355	\|\| (c >= '0' && c <= '9') \|\| c == '_');
356
357	if (opening_brace)
358	{
359	if (c == '}')
360	{
361	closing_brace = 1;
362	valid = 1;
363	}
364	else
365	{
366	valid = 0;
367	do_ungetc (c);
368	}
369	}
370	else
371	{
372	valid = 1;
373	do_ungetc (c);
374	}
375
376	if (valid)
377	{
378	/* Terminate the variable in the buffer. */
379	if (buflen >= bufmax)
380	{
381	bufmax = 2 * bufmax + 10;
382	buffer = xrealloc (buffer, bufmax);
383	}
384	buffer[buflen] = '\0';
385
386	/* Test whether the variable shall be substituted. */
387	if (!all_variables
388	&& !sorted_string_list_member (&variables_set, buffer))
389	valid = 0;
390	}
391
392	if (valid)
393	{
394	/* Substitute the variable's value from the environment. */
395	const char *env_value = getenv (buffer);
396
397	if (env_value != NULL)
398	fputs (env_value, stdout);
399	}
400	else
401	{
402	/* Perform no substitution at all. Since the buffered input
403	contains no other '$' than at the start, we can just
404	output all the buffered contents. */
405	putchar ('$');
406	if (opening_brace)
407	putchar ('{');
408	fwrite (buffer, buflen, 1, stdout);
409	if (closing_brace)
410	putchar ('}');
411	}
412	}
413	else
414	{
415	do_ungetc (c);
416	putchar ('$');
417	if (opening_brace)
418	putchar ('{');
419	}
420	}
421	else
422	putchar (c);
423	}
424	}