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Diffstat (limited to 'tilde.c')
| -rw-r--r-- | tilde.c | 386 |
1 files changed, 386 insertions, 0 deletions
@@ -0,0 +1,386 @@ +/* tilde.c -- Tilde expansion code (~/foo := $HOME/foo). */ + +/* Copyright (C) 1988,1989 Free Software Foundation, Inc. + + This file is part of GNU Readline, a library for reading lines + of text with interactive input and history editing. + + Readline 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 1, or (at your option) any + later version. + + Readline 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 Readline; see the file COPYING. If not, write to the Free + Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ + +#include "memalloc.h" + +#if defined (HAVE_STRING_H) +# include <string.h> +#else /* !HAVE_STRING_H */ +# include <strings.h> +#endif /* !HAVE_STRING_H */ + +#if defined (HAVE_STDLIB_H) +# include <stdlib.h> +#else +# include "ansi_stdlib.h" +#endif /* HAVE_STDLIB_H */ + +#include "tilde.h" +#include <pwd.h> + +#if defined (USG) && !defined (HAVE_GETPW_DECLS) +extern struct passwd *getpwuid (), *getpwnam (); +#endif /* USG && !defined (HAVE_GETPW_DECLS) */ + +#if !defined (savestring) +extern char *xmalloc (); +# ifndef strcpy +extern char *strcpy (); +# endif +#define savestring(x) strcpy (xmalloc (1 + strlen (x)), (x)) +#endif /* !savestring */ + +#if !defined (NULL) +# if defined (__STDC__) +# define NULL ((void *) 0) +# else +# define NULL 0x0 +# endif /* !__STDC__ */ +#endif /* !NULL */ + +#if defined (TEST) || defined (STATIC_MALLOC) +static char *xmalloc (), *xrealloc (); +#else +extern char *xmalloc (), *xrealloc (); +#endif /* TEST || STATIC_MALLOC */ + +/* The default value of tilde_additional_prefixes. This is set to + whitespace preceding a tilde so that simple programs which do not + perform any word separation get desired behaviour. */ +static char *default_prefixes[] = + { " ~", "\t~", (char *)NULL }; + +/* The default value of tilde_additional_suffixes. This is set to + whitespace or newline so that simple programs which do not + perform any word separation get desired behaviour. */ +static char *default_suffixes[] = + { " ", "\n", (char *)NULL }; + +/* If non-null, this contains the address of a function to call if the + standard meaning for expanding a tilde fails. The function is called + with the text (sans tilde, as in "foo"), and returns a malloc()'ed string + which is the expansion, or a NULL pointer if there is no expansion. */ +CPFunction *tilde_expansion_failure_hook = (CPFunction *)NULL; + +/* When non-null, this is a NULL terminated array of strings which + are duplicates for a tilde prefix. Bash uses this to expand + `=~' and `:~'. */ +char **tilde_additional_prefixes = default_prefixes; + +/* When non-null, this is a NULL terminated array of strings which match + the end of a username, instead of just "/". Bash sets this to + `:' and `=~'. */ +char **tilde_additional_suffixes = default_suffixes; + +/* Find the start of a tilde expansion in STRING, and return the index of + the tilde which starts the expansion. Place the length of the text + which identified this tilde starter in LEN, excluding the tilde itself. */ +static int +tilde_find_prefix (string, len) + char *string; + int *len; +{ + register int i, j, string_len; + register char **prefixes = tilde_additional_prefixes; + + string_len = strlen (string); + *len = 0; + + if (!*string || *string == '~') + return (0); + + if (prefixes) + { + for (i = 0; i < string_len; i++) + { + for (j = 0; prefixes[j]; j++) + { + if (strncmp (string + i, prefixes[j], strlen (prefixes[j])) == 0) + { + *len = strlen (prefixes[j]) - 1; + return (i + *len); + } + } + } + } + return (string_len); +} + +/* Find the end of a tilde expansion in STRING, and return the index of + the character which ends the tilde definition. */ +static int +tilde_find_suffix (string) + char *string; +{ + register int i, j, string_len; + register char **suffixes = tilde_additional_suffixes; + + string_len = strlen (string); + + for (i = 0; i < string_len; i++) + { + if (string[i] == '/' || !string[i]) + break; + + for (j = 0; suffixes && suffixes[j]; j++) + { + if (strncmp (string + i, suffixes[j], strlen (suffixes[j])) == 0) + return (i); + } + } + return (i); +} + +/* Return a new string which is the result of tilde expanding STRING. */ +char * +tilde_expand (string) + char *string; +{ + char *result, *tilde_expand_word (); + int result_size, result_index; + + result_size = result_index = 0; + result = (char *)NULL; + + /* Scan through STRING expanding tildes as we come to them. */ + while (1) + { + register int start, end; + char *tilde_word, *expansion; + int len; + + /* Make START point to the tilde which starts the expansion. */ + start = tilde_find_prefix (string, &len); + + /* Copy the skipped text into the result. */ + if ((result_index + start + 1) > result_size) + result = (char *)xrealloc (result, 1 + (result_size += (start + 20))); + + strncpy (result + result_index, string, start); + result_index += start; + + /* Advance STRING to the starting tilde. */ + string += start; + + /* Make END be the index of one after the last character of the + username. */ + end = tilde_find_suffix (string); + + /* If both START and END are zero, we are all done. */ + if (!start && !end) + break; + + /* Expand the entire tilde word, and copy it into RESULT. */ + tilde_word = (char *)xmalloc (1 + end); + strncpy (tilde_word, string, end); + tilde_word[end] = '\0'; + string += end; + + expansion = tilde_expand_word (tilde_word); + free (tilde_word); + + len = strlen (expansion); + if ((result_index + len + 1) > result_size) + result = (char *)xrealloc (result, 1 + (result_size += (len + 20))); + + strcpy (result + result_index, expansion); + result_index += len; + free (expansion); + } + + result[result_index] = '\0'; + + return (result); +} + +/* Do the work of tilde expansion on FILENAME. FILENAME starts with a + tilde. If there is no expansion, call tilde_expansion_failure_hook. */ +char * +tilde_expand_word (filename) + char *filename; +{ + char *dirname; + + dirname = filename ? savestring (filename) : (char *)NULL; + + if (dirname && *dirname == '~') + { + char *temp_name; + if (!dirname[1] || dirname[1] == '/') + { + /* Prepend $HOME to the rest of the string. */ + char *temp_home = (char *)getenv ("HOME"); + + /* If there is no HOME variable, look up the directory in + the password database. */ + if (!temp_home) + { + struct passwd *entry; + + entry = getpwuid (getuid ()); + if (entry) + temp_home = entry->pw_dir; + } + + temp_name = xmalloc (1 + strlen (&dirname[1]) + + (temp_home ? strlen (temp_home) : 0)); + temp_name[0] = '\0'; + if (temp_home) + strcpy (temp_name, temp_home); + strcat (temp_name, dirname + 1); + free (dirname); + dirname = temp_name; + } + else + { + char u_name[257]; + struct passwd *user_entry; + char *username; + int i, c; + + username = u_name; + for (i = 1; c = dirname[i]; i++) + { + if (c == '/') + break; + else + username[i - 1] = c; + } + username[i - 1] = '\0'; + + if (!(user_entry = getpwnam (username))) + { + /* If the calling program has a special syntax for + expanding tildes, and we couldn't find a standard + expansion, then let them try. */ + if (tilde_expansion_failure_hook) + { + char *expansion; + + expansion = (*tilde_expansion_failure_hook) (username); + + if (expansion) + { + temp_name = xmalloc (1 + strlen (expansion) + + strlen (&dirname[i])); + strcpy (temp_name, expansion); + strcat (temp_name, &dirname[i]); + free (expansion); + free (dirname); + dirname = temp_name; + } + } + /* We shouldn't report errors. */ + } + else + { + temp_name = xmalloc (1 + strlen (user_entry->pw_dir) + + strlen (&dirname[i])); + strcpy (temp_name, user_entry->pw_dir); + strcat (temp_name, &dirname[i]); + free (dirname); + dirname = temp_name; + } + endpwent (); + } + } + return (dirname); +} + + +#if defined (TEST) +#undef NULL +#include <stdio.h> + +main (argc, argv) + int argc; + char **argv; +{ + char *result, line[512]; + int done = 0; + + while (!done) + { + printf ("~expand: "); + fflush (stdout); + + if (!gets (line)) + strcpy (line, "done"); + + if ((strcmp (line, "done") == 0) || + (strcmp (line, "quit") == 0) || + (strcmp (line, "exit") == 0)) + { + done = 1; + break; + } + + result = tilde_expand (line); + printf (" --> %s\n", result); + free (result); + } + exit (0); +} + +static void memory_error_and_abort (); + +static char * +xmalloc (bytes) + int bytes; +{ + char *temp = (char *)malloc (bytes); + + if (!temp) + memory_error_and_abort (); + return (temp); +} + +static char * +xrealloc (pointer, bytes) + char *pointer; + int bytes; +{ + char *temp; + + if (!pointer) + temp = (char *)malloc (bytes); + else + temp = (char *)realloc (pointer, bytes); + + if (!temp) + memory_error_and_abort (); + + return (temp); +} + +static void +memory_error_and_abort () +{ + fprintf (stderr, "readline: Out of virtual memory!\n"); + abort (); +} + +/* + * Local variables: + * compile-command: "gcc -g -DTEST -o tilde tilde.c" + * end: + */ +#endif /* TEST */ |