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-rw-r--r--braces.c687
1 files changed, 687 insertions, 0 deletions
diff --git a/braces.c b/braces.c
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+/* braces.c -- code for doing word expansion in curly braces. */
+
+/* Copyright (C) 1987-2009 Free Software Foundation, Inc.
+
+ This file is part of GNU Bash, the Bourne Again SHell.
+
+ Bash 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.
+
+ Bash 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 Bash. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/* Stuff in curly braces gets expanded before all other shell expansions. */
+
+#include "config.h"
+
+#if defined (BRACE_EXPANSION)
+
+#if defined (HAVE_UNISTD_H)
+# ifdef _MINIX
+# include <sys/types.h>
+# endif
+# include <unistd.h>
+#endif
+
+#include "bashansi.h"
+
+#if defined (SHELL)
+# include "shell.h"
+#endif /* SHELL */
+
+#include "general.h"
+#include "shmbutil.h"
+#include "chartypes.h"
+
+#define brace_whitespace(c) (!(c) || (c) == ' ' || (c) == '\t' || (c) == '\n')
+
+#define BRACE_SEQ_SPECIFIER ".."
+
+extern int asprintf __P((char **, const char *, ...)) __attribute__((__format__ (printf, 2, 3)));
+
+/* Basic idea:
+
+ Segregate the text into 3 sections: preamble (stuff before an open brace),
+ postamble (stuff after the matching close brace) and amble (stuff after
+ preamble, and before postamble). Expand amble, and then tack on the
+ expansions to preamble. Expand postamble, and tack on the expansions to
+ the result so far.
+ */
+
+/* The character which is used to separate arguments. */
+static const int brace_arg_separator = ',';
+
+#if defined (__P)
+static int brace_gobbler __P((char *, size_t, int *, int));
+static char **expand_amble __P((char *, size_t, int));
+static char **expand_seqterm __P((char *, size_t));
+static char **mkseq __P((int, int, int, int, int));
+static char **array_concat __P((char **, char **));
+#else
+static int brace_gobbler ();
+static char **expand_amble ();
+static char **expand_seqterm ();
+static char **mkseq();
+static char **array_concat ();
+#endif
+
+#if 0
+static void
+dump_result (a)
+ char **a;
+{
+ int i;
+
+ for (i = 0; a[i]; i++)
+ printf ("dump_result: a[%d] = -%s-\n", i, a[i]);
+}
+#endif
+
+/* Return an array of strings; the brace expansion of TEXT. */
+char **
+brace_expand (text)
+ char *text;
+{
+ register int start;
+ size_t tlen;
+ char *preamble, *postamble, *amble;
+ size_t alen;
+ char **tack, **result;
+ int i, j, c, c1;
+
+ DECLARE_MBSTATE;
+
+ /* Find the text of the preamble. */
+ tlen = strlen (text);
+ i = 0;
+#if defined (CSH_BRACE_COMPAT)
+ c = brace_gobbler (text, tlen, &i, '{'); /* } */
+#else
+ /* Make sure that when we exit this loop, c == 0 or text[i] begins a
+ valid brace expansion sequence. */
+ do
+ {
+ c = brace_gobbler (text, tlen, &i, '{'); /* } */
+ c1 = c;
+ /* Verify that c begins a valid brace expansion word. If it doesn't, we
+ go on. Loop stops when there are no more open braces in the word. */
+ if (c)
+ {
+ start = j = i + 1; /* { */
+ c = brace_gobbler (text, tlen, &j, '}');
+ if (c == 0) /* it's not */
+ {
+ i++;
+ c = c1;
+ continue;
+ }
+ else /* it is */
+ {
+ c = c1;
+ break;
+ }
+ }
+ else
+ break;
+ }
+ while (c);
+#endif /* !CSH_BRACE_COMPAT */
+
+ preamble = (char *)xmalloc (i + 1);
+ strncpy (preamble, text, i);
+ preamble[i] = '\0';
+
+ result = (char **)xmalloc (2 * sizeof (char *));
+ result[0] = preamble;
+ result[1] = (char *)NULL;
+
+ /* Special case. If we never found an exciting character, then
+ the preamble is all of the text, so just return that. */
+ if (c != '{')
+ return (result);
+
+ /* Find the amble. This is the stuff inside this set of braces. */
+ start = ++i;
+ c = brace_gobbler (text, tlen, &i, '}');
+
+ /* What if there isn't a matching close brace? */
+ if (c == 0)
+ {
+#if defined (NOTDEF)
+ /* Well, if we found an unquoted BRACE_ARG_SEPARATOR between START
+ and I, then this should be an error. Otherwise, it isn't. */
+ j = start;
+ while (j < i)
+ {
+ if (text[j] == '\\')
+ {
+ j++;
+ ADVANCE_CHAR (text, tlen, j);
+ continue;
+ }
+
+ if (text[j] == brace_arg_separator)
+ { /* { */
+ strvec_dispose (result);
+ report_error ("no closing `%c' in %s", '}', text);
+ throw_to_top_level ();
+ }
+ ADVANCE_CHAR (text, tlen, j);
+ }
+#endif
+ free (preamble); /* Same as result[0]; see initialization. */
+ result[0] = savestring (text);
+ return (result);
+ }
+
+#if defined (SHELL)
+ amble = substring (text, start, i);
+ alen = i - start;
+#else
+ amble = (char *)xmalloc (1 + (i - start));
+ strncpy (amble, &text[start], (i - start));
+ alen = i - start;
+ amble[alen] = '\0';
+#endif
+
+#if defined (SHELL)
+ INITIALIZE_MBSTATE;
+
+ /* If the amble does not contain an unquoted BRACE_ARG_SEPARATOR, then
+ just return without doing any expansion. */
+ j = 0;
+ while (amble[j])
+ {
+ if (amble[j] == '\\')
+ {
+ j++;
+ ADVANCE_CHAR (amble, alen, j);
+ continue;
+ }
+
+ if (amble[j] == brace_arg_separator)
+ break;
+
+ ADVANCE_CHAR (amble, alen, j);
+ }
+
+ if (amble[j] == 0)
+ {
+ tack = expand_seqterm (amble, alen);
+ if (tack)
+ goto add_tack;
+ else
+ {
+ free (amble);
+ free (preamble);
+ result[0] = savestring (text);
+ return (result);
+ }
+ }
+#endif /* SHELL */
+
+ tack = expand_amble (amble, alen, 0);
+add_tack:
+ result = array_concat (result, tack);
+ free (amble);
+ strvec_dispose (tack);
+
+ postamble = text + i + 1;
+
+ tack = brace_expand (postamble);
+ result = array_concat (result, tack);
+ strvec_dispose (tack);
+
+ return (result);
+}
+
+/* Expand the text found inside of braces. We simply try to split the
+ text at BRACE_ARG_SEPARATORs into separate strings. We then brace
+ expand each slot which needs it, until there are no more slots which
+ need it. */
+static char **
+expand_amble (text, tlen, flags)
+ char *text;
+ size_t tlen;
+ int flags;
+{
+ char **result, **partial;
+ char *tem;
+ int start, i, c;
+
+ DECLARE_MBSTATE;
+
+ result = (char **)NULL;
+
+ start = i = 0;
+ c = 1;
+ while (c)
+ {
+ c = brace_gobbler (text, tlen, &i, brace_arg_separator);
+#if defined (SHELL)
+ tem = substring (text, start, i);
+#else
+ tem = (char *)xmalloc (1 + (i - start));
+ strncpy (tem, &text[start], (i - start));
+ tem[i- start] = '\0';
+#endif
+
+ partial = brace_expand (tem);
+
+ if (!result)
+ result = partial;
+ else
+ {
+ register int lr, lp, j;
+
+ lr = strvec_len (result);
+ lp = strvec_len (partial);
+
+ result = strvec_resize (result, lp + lr + 1);
+
+ for (j = 0; j < lp; j++)
+ result[lr + j] = partial[j];
+
+ result[lr + j] = (char *)NULL;
+ free (partial);
+ }
+ free (tem);
+ ADVANCE_CHAR (text, tlen, i);
+ start = i;
+ }
+ return (result);
+}
+
+#define ST_BAD 0
+#define ST_INT 1
+#define ST_CHAR 2
+#define ST_ZINT 3
+
+static char **
+mkseq (start, end, incr, type, width)
+ int start, end, incr, type, width;
+{
+ int n, i;
+ char **result, *t;
+
+ n = abs (end - start) + 1;
+ result = strvec_create (n + 1);
+
+ if (incr == 0)
+ incr = 1;
+
+ if (start > end && incr > 0)
+ incr = -incr;
+ else if (start < end && incr < 0)
+ incr = -incr;
+
+ /* Make sure we go through the loop at least once, so {3..3} prints `3' */
+ i = 0;
+ n = start;
+ do
+ {
+#if defined (SHELL)
+ QUIT; /* XXX - memory leak here */
+#endif
+ if (type == ST_INT)
+ result[i++] = itos (n);
+ else if (type == ST_ZINT)
+ {
+ int len;
+ len = asprintf (&t, "%0*d", width, n);
+ result[i++] = t;
+ }
+ else
+ {
+ t = (char *)xmalloc (2);
+ t[0] = n;
+ t[1] = '\0';
+ result[i++] = t;
+ }
+ n += incr;
+ if ((incr < 0 && n < end) || (incr > 0 && n > end))
+ break;
+ }
+ while (1);
+
+ result[i] = (char *)0;
+ return (result);
+}
+
+static char **
+expand_seqterm (text, tlen)
+ char *text;
+ size_t tlen;
+{
+ char *t, *lhs, *rhs;
+ int i, lhs_t, rhs_t, lhs_v, rhs_v, incr, lhs_l, rhs_l, width;
+ intmax_t tl, tr;
+ char **result, *ep, *oep;
+
+ t = strstr (text, BRACE_SEQ_SPECIFIER);
+ if (t == 0)
+ return ((char **)NULL);
+
+ lhs_l = t - text; /* index of start of BRACE_SEQ_SPECIFIER */
+ lhs = substring (text, 0, lhs_l);
+ rhs = substring (text, lhs_l + sizeof(BRACE_SEQ_SPECIFIER) - 1, tlen);
+
+ if (lhs[0] == 0 || rhs[0] == 0)
+ {
+ free (lhs);
+ free (rhs);
+ return ((char **)NULL);
+ }
+
+ /* Now figure out whether LHS and RHS are integers or letters. Both
+ sides have to match. */
+ lhs_t = (legal_number (lhs, &tl)) ? ST_INT :
+ ((ISALPHA (lhs[0]) && lhs[1] == 0) ? ST_CHAR : ST_BAD);
+
+ /* Decide on rhs and whether or not it looks like the user specified
+ an increment */
+ ep = 0;
+ if (ISDIGIT (rhs[0]) || ((rhs[0] == '+' || rhs[0] == '-') && ISDIGIT (rhs[1])))
+ {
+ rhs_t = ST_INT;
+ tr = strtoimax (rhs, &ep, 10);
+ if (ep && *ep != 0 && *ep != '.')
+ rhs_t = ST_BAD; /* invalid */
+ }
+ else if (ISALPHA (rhs[0]) && (rhs[1] == 0 || rhs[1] == '.'))
+ {
+ rhs_t = ST_CHAR;
+ ep = rhs + 1;
+ }
+ else
+ {
+ rhs_t = ST_BAD;
+ ep = 0;
+ }
+
+ incr = 1;
+ if (rhs_t != ST_BAD)
+ {
+ oep = ep;
+ if (ep && *ep == '.' && ep[1] == '.' && ep[2])
+ incr = strtoimax (ep + 2, &ep, 10);
+ if (*ep != 0)
+ rhs_t = ST_BAD; /* invalid incr */
+ tlen -= ep - oep;
+ }
+
+ if (lhs_t != rhs_t || lhs_t == ST_BAD || rhs_t == ST_BAD)
+ {
+ free (lhs);
+ free (rhs);
+ return ((char **)NULL);
+ }
+
+ /* OK, we have something. It's either a sequence of integers, ascending
+ or descending, or a sequence or letters, ditto. Generate the sequence,
+ put it into a string vector, and return it. */
+
+ if (lhs_t == ST_CHAR)
+ {
+ lhs_v = (unsigned char)lhs[0];
+ rhs_v = (unsigned char)rhs[0];
+ width = 1;
+ }
+ else
+ {
+ lhs_v = tl; /* integer truncation */
+ rhs_v = tr;
+
+ /* Decide whether or not the terms need zero-padding */
+ rhs_l = tlen - lhs_l - sizeof (BRACE_SEQ_SPECIFIER) + 1;
+ width = 0;
+ if (lhs_l > 1 && lhs[0] == '0')
+ width = lhs_l, lhs_t = ST_ZINT;
+ if (lhs_l > 2 && lhs[0] == '-' && lhs[1] == '0')
+ width = lhs_l, lhs_t = ST_ZINT;
+ if (rhs_l > 1 && rhs[0] == '0' && width < rhs_l)
+ width = rhs_l, lhs_t = ST_ZINT;
+ if (rhs_l > 2 && rhs[0] == '-' && rhs[1] == '0' && width < rhs_l)
+ width = rhs_l, lhs_t = ST_ZINT;
+
+ if (width < lhs_l && lhs_t == ST_ZINT)
+ width = lhs_l;
+ if (width < rhs_l && lhs_t == ST_ZINT)
+ width = rhs_l;
+ }
+
+ result = mkseq (lhs_v, rhs_v, incr, lhs_t, width);
+
+ free (lhs);
+ free (rhs);
+
+ return (result);
+}
+
+/* Start at INDEX, and skip characters in TEXT. Set INDEX to the
+ index of the character matching SATISFY. This understands about
+ quoting. Return the character that caused us to stop searching;
+ this is either the same as SATISFY, or 0. */
+/* If SATISFY is `}', we are looking for a brace expression, so we
+ should enforce the rules that govern valid brace expansions:
+ 1) to count as an arg separator, a comma or `..' has to be outside
+ an inner set of braces.
+*/
+static int
+brace_gobbler (text, tlen, indx, satisfy)
+ char *text;
+ size_t tlen;
+ int *indx;
+ int satisfy;
+{
+ register int i, c, quoted, level, commas, pass_next;
+#if defined (SHELL)
+ int si;
+ char *t;
+#endif
+ DECLARE_MBSTATE;
+
+ level = quoted = pass_next = 0;
+#if defined (CSH_BRACE_COMPAT)
+ commas = 1;
+#else
+ commas = (satisfy == '}') ? 0 : 1;
+#endif
+
+ i = *indx;
+ while (c = text[i])
+ {
+ if (pass_next)
+ {
+ pass_next = 0;
+ ADVANCE_CHAR (text, tlen, i);
+ continue;
+ }
+
+ /* A backslash escapes the next character. This allows backslash to
+ escape the quote character in a double-quoted string. */
+ if (c == '\\' && (quoted == 0 || quoted == '"' || quoted == '`'))
+ {
+ pass_next = 1;
+ i++;
+ continue;
+ }
+
+#if defined (SHELL)
+ /* If compiling for the shell, treat ${...} like \{...} */
+ if (c == '$' && text[i+1] == '{' && quoted != '\'') /* } */
+ {
+ pass_next = 1;
+ i++;
+ if (quoted == 0)
+ level++;
+ continue;
+ }
+#endif
+
+ if (quoted)
+ {
+ if (c == quoted)
+ quoted = 0;
+ ADVANCE_CHAR (text, tlen, i);
+ continue;
+ }
+
+ if (c == '"' || c == '\'' || c == '`')
+ {
+ quoted = c;
+ i++;
+ continue;
+ }
+
+#if defined (SHELL)
+ /* Pass new-style command and process substitutions through unchanged. */
+ if ((c == '$' || c == '<' || c == '>') && text[i+1] == '(') /* ) */
+ {
+ si = i + 2;
+ t = extract_command_subst (text, &si, 0);
+ i = si;
+ free (t);
+ i++;
+ continue;
+ }
+#endif
+
+ if (c == satisfy && level == 0 && quoted == 0 && commas > 0)
+ {
+ /* We ignore an open brace surrounded by whitespace, and also
+ an open brace followed immediately by a close brace preceded
+ by whitespace. */
+ if (c == '{' &&
+ ((!i || brace_whitespace (text[i - 1])) &&
+ (brace_whitespace (text[i + 1]) || text[i + 1] == '}')))
+ {
+ i++;
+ continue;
+ }
+
+ break;
+ }
+
+ if (c == '{')
+ level++;
+ else if (c == '}' && level)
+ level--;
+#if !defined (CSH_BRACE_COMPAT)
+ else if (satisfy == '}' && c == brace_arg_separator && level == 0)
+ commas++;
+ else if (satisfy == '}' && STREQN (text+i, BRACE_SEQ_SPECIFIER, 2) &&
+ text[i+2] != satisfy && level == 0)
+ commas++;
+#endif
+
+ ADVANCE_CHAR (text, tlen, i);
+ }
+
+ *indx = i;
+ return (c);
+}
+
+/* Return a new array of strings which is the result of appending each
+ string in ARR2 to each string in ARR1. The resultant array is
+ len (arr1) * len (arr2) long. For convenience, ARR1 (and its contents)
+ are free ()'ed. ARR1 can be NULL, in that case, a new version of ARR2
+ is returned. */
+static char **
+array_concat (arr1, arr2)
+ char **arr1, **arr2;
+{
+ register int i, j, len, len1, len2;
+ register char **result;
+
+ if (arr1 == 0)
+ return (strvec_copy (arr2));
+
+ if (arr2 == 0)
+ return (strvec_copy (arr1));
+
+ len1 = strvec_len (arr1);
+ len2 = strvec_len (arr2);
+
+ result = (char **)xmalloc ((1 + (len1 * len2)) * sizeof (char *));
+
+ len = 0;
+ for (i = 0; i < len1; i++)
+ {
+ int strlen_1 = strlen (arr1[i]);
+
+ for (j = 0; j < len2; j++)
+ {
+ result[len] = (char *)xmalloc (1 + strlen_1 + strlen (arr2[j]));
+ strcpy (result[len], arr1[i]);
+ strcpy (result[len] + strlen_1, arr2[j]);
+ len++;
+ }
+ free (arr1[i]);
+ }
+ free (arr1);
+
+ result[len] = (char *)NULL;
+ return (result);
+}
+
+#if defined (TEST)
+#include <stdio.h>
+
+fatal_error (format, arg1, arg2)
+ char *format, *arg1, *arg2;
+{
+ report_error (format, arg1, arg2);
+ exit (1);
+}
+
+report_error (format, arg1, arg2)
+ char *format, *arg1, *arg2;
+{
+ fprintf (stderr, format, arg1, arg2);
+ fprintf (stderr, "\n");
+}
+
+main ()
+{
+ char example[256];
+
+ for (;;)
+ {
+ char **result;
+ int i;
+
+ fprintf (stderr, "brace_expand> ");
+
+ if ((!fgets (example, 256, stdin)) ||
+ (strncmp (example, "quit", 4) == 0))
+ break;
+
+ if (strlen (example))
+ example[strlen (example) - 1] = '\0';
+
+ result = brace_expand (example);
+
+ for (i = 0; result[i]; i++)
+ printf ("%s\n", result[i]);
+
+ free_array (result);
+ }
+}
+
+/*
+ * Local variables:
+ * compile-command: "gcc -g -Bstatic -DTEST -o brace_expand braces.c general.o"
+ * end:
+ */
+
+#endif /* TEST */
+#endif /* BRACE_EXPANSION */