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+/*
+ * 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, write to the Free Software Foundation,
+ Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+/* 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, write to the Free Software Foundation,
+ Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+#include <errno.h>
+#include <getopt.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
+main (int argc, 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");
+ /*
+ 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)
+ {
+ size_t nbytes;
+
+ slp->nitems_max = slp->nitems_max * 2 + 4;
+ nbytes = slp->nitems_max * sizeof (slp->item[0]);
+ slp->item = (const char **) xrealloc (slp->item, nbytes);
+ }
+
+ /* 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)
+{
+ if (slp->nitems > 0)
+ qsort (slp->item, slp->nitems, sizeof (slp->item[0]), cmp_string);
+}
+
+/* Test whether a string list contains a given string. */
+static inline int
+string_list_member (const string_list_ty *slp, const char *s)
+{
+ size_t j;
+
+ for (j = 0; j < slp->nitems; ++j)
+ if (strcmp (slp->item[j], s) == 0)
+ return 1;
+ return 0;
+}
+
+/* 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 = xmalloc (var_len + 1);
+ memcpy (string, var_ptr, var_len);
+ string[var_len] = '\0';
+
+ 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);
+ }
+}