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Diffstat (limited to '')
-rw-r--r-- | builtins/umask.def | 317 |
1 files changed, 317 insertions, 0 deletions
diff --git a/builtins/umask.def b/builtins/umask.def new file mode 100644 index 0000000..d3138d4 --- /dev/null +++ b/builtins/umask.def @@ -0,0 +1,317 @@ +This file is umask.def, from which is created umask.c. +It implements the builtin "umask" in Bash. + +Copyright (C) 1987-2015 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/>. + +$PRODUCES umask.c + +$BUILTIN umask +$FUNCTION umask_builtin +$SHORT_DOC umask [-p] [-S] [mode] +Display or set file mode mask. + +Sets the user file-creation mask to MODE. If MODE is omitted, prints +the current value of the mask. + +If MODE begins with a digit, it is interpreted as an octal number; +otherwise it is a symbolic mode string like that accepted by chmod(1). + +Options: + -p if MODE is omitted, output in a form that may be reused as input + -S makes the output symbolic; otherwise an octal number is output + +Exit Status: +Returns success unless MODE is invalid or an invalid option is given. +$END + +#include <config.h> + +#include "../bashtypes.h" +#include "filecntl.h" +#if ! defined(_MINIX) && defined (HAVE_SYS_FILE_H) +# include <sys/file.h> +#endif + +#if defined (HAVE_UNISTD_H) +#include <unistd.h> +#endif + +#include <stdio.h> +#include <chartypes.h> + +#include "../bashintl.h" + +#include "../shell.h" +#include "posixstat.h" +#include "common.h" +#include "bashgetopt.h" + +/* **************************************************************** */ +/* */ +/* UMASK Builtin and Helpers */ +/* */ +/* **************************************************************** */ + +static void print_symbolic_umask __P((mode_t)); +static int symbolic_umask __P((WORD_LIST *)); + +/* Set or display the mask used by the system when creating files. Flag + of -S means display the umask in a symbolic mode. */ +int +umask_builtin (list) + WORD_LIST *list; +{ + int print_symbolically, opt, umask_value, pflag; + mode_t umask_arg; + + print_symbolically = pflag = 0; + reset_internal_getopt (); + while ((opt = internal_getopt (list, "Sp")) != -1) + { + switch (opt) + { + case 'S': + print_symbolically++; + break; + case 'p': + pflag++; + break; + CASE_HELPOPT; + default: + builtin_usage (); + return (EX_USAGE); + } + } + + list = loptend; + + if (list) + { + if (DIGIT (*list->word->word)) + { + umask_value = read_octal (list->word->word); + + /* Note that other shells just let you set the umask to zero + by specifying a number out of range. This is a problem + with those shells. We don't change the umask if the input + is lousy. */ + if (umask_value == -1) + { + sh_erange (list->word->word, _("octal number")); + return (EXECUTION_FAILURE); + } + } + else + { + umask_value = symbolic_umask (list); + if (umask_value == -1) + return (EXECUTION_FAILURE); + } + umask_arg = (mode_t)umask_value; + umask (umask_arg); + if (print_symbolically) + print_symbolic_umask (umask_arg); + } + else /* Display the UMASK for this user. */ + { + umask_arg = umask (022); + umask (umask_arg); + + if (pflag) + printf ("umask%s ", (print_symbolically ? " -S" : "")); + if (print_symbolically) + print_symbolic_umask (umask_arg); + else + printf ("%04lo\n", (unsigned long)umask_arg); + } + + return (sh_chkwrite (EXECUTION_SUCCESS)); +} + +/* Print the umask in a symbolic form. In the output, a letter is + printed if the corresponding bit is clear in the umask. */ +static void +#if defined (__STDC__) +print_symbolic_umask (mode_t um) +#else +print_symbolic_umask (um) + mode_t um; +#endif +{ + char ubits[4], gbits[4], obits[4]; /* u=rwx,g=rwx,o=rwx */ + int i; + + i = 0; + if ((um & S_IRUSR) == 0) + ubits[i++] = 'r'; + if ((um & S_IWUSR) == 0) + ubits[i++] = 'w'; + if ((um & S_IXUSR) == 0) + ubits[i++] = 'x'; + ubits[i] = '\0'; + + i = 0; + if ((um & S_IRGRP) == 0) + gbits[i++] = 'r'; + if ((um & S_IWGRP) == 0) + gbits[i++] = 'w'; + if ((um & S_IXGRP) == 0) + gbits[i++] = 'x'; + gbits[i] = '\0'; + + i = 0; + if ((um & S_IROTH) == 0) + obits[i++] = 'r'; + if ((um & S_IWOTH) == 0) + obits[i++] = 'w'; + if ((um & S_IXOTH) == 0) + obits[i++] = 'x'; + obits[i] = '\0'; + + printf ("u=%s,g=%s,o=%s\n", ubits, gbits, obits); +} + +int +parse_symbolic_mode (mode, initial_bits) + char *mode; + int initial_bits; +{ + int who, op, perm, bits, c; + char *s; + + for (s = mode, bits = initial_bits;;) + { + who = op = perm = 0; + + /* Parse the `who' portion of the symbolic mode clause. */ + while (member (*s, "agou")) + { + switch (c = *s++) + { + case 'u': + who |= S_IRWXU; + continue; + case 'g': + who |= S_IRWXG; + continue; + case 'o': + who |= S_IRWXO; + continue; + case 'a': + who |= S_IRWXU | S_IRWXG | S_IRWXO; + continue; + default: + break; + } + } + + /* The operation is now sitting in *s. */ + op = *s++; + switch (op) + { + case '+': + case '-': + case '=': + break; + default: + builtin_error (_("`%c': invalid symbolic mode operator"), op); + return (-1); + } + + /* Parse out the `perm' section of the symbolic mode clause. */ + while (member (*s, "rwx")) + { + c = *s++; + + switch (c) + { + case 'r': + perm |= S_IRUGO; + break; + case 'w': + perm |= S_IWUGO; + break; + case 'x': + perm |= S_IXUGO; + break; + } + } + + /* Now perform the operation or return an error for a + bad permission string. */ + if (!*s || *s == ',') + { + if (who) + perm &= who; + + switch (op) + { + case '+': + bits |= perm; + break; + case '-': + bits &= ~perm; + break; + case '=': + if (who == 0) + who = S_IRWXU | S_IRWXG | S_IRWXO; + bits &= ~who; + bits |= perm; + break; + + /* No other values are possible. */ + } + + if (*s == '\0') + break; + else + s++; /* skip past ',' */ + } + else + { + builtin_error (_("`%c': invalid symbolic mode character"), *s); + return (-1); + } + } + + return (bits); +} + +/* Set the umask from a symbolic mode string similar to that accepted + by chmod. If the -S argument is given, then print the umask in a + symbolic form. */ +static int +symbolic_umask (list) + WORD_LIST *list; +{ + int um, bits; + + /* Get the initial umask. Don't change it yet. */ + um = umask (022); + umask (um); + + /* All work is done with the complement of the umask -- it's + more intuitive and easier to deal with. It is complemented + again before being returned. */ + bits = parse_symbolic_mode (list->word->word, ~um & 0777); + if (bits == -1) + return (-1); + + um = ~bits & 0777; + return (um); +} |