getopt: add feature to ignore unknown options

This feature addition will add the '-U' and '--unknown' options
It'll allow getopt to ignore unknown options and leave them untouched.
Additionally, it will surpress any error messages generated by getopt(3).

Addresses: #701
Signed-off-by: Christian Goeschel Ndjomouo <cgoesc2@wgu.edu>

diff --git a/Documentation/TODO b/Documentation/TODO
index 880a92cde576465118878d693d4581f82933bec9..f62acdb49d7012093a67c3193439945b51e11540 100644 (file)
--- a/Documentation/TODO
+++ b/Documentation/TODO
@@ -103,15 +103,6 @@ partx
 
  - support mapping by device-mapper if argv[0] is "kpartx" or --dm option is used.
 
-
-getopt
-------
-  It would be great if getopt could optionally ignore unknown options.
-  Currently, it outputs -- for every option it doesn't recognize but leaving the
-  option as it is could beneficial wrapper scripts which could then pass the
-  options they don't recognize as they are to the command they are wrapping.
-  https://github.com/util-linux/util-linux/issues/701
-
 docs
 ----
 

diff --git a/misc-utils/getopt.1.adoc b/misc-utils/getopt.1.adoc
index 0108c300aae12d959a16ab349f9bed1050101526..5fa729a52d33d4bbae2efdf16e93f71d7977ae9a 100644 (file)
--- a/misc-utils/getopt.1.adoc
+++ b/misc-utils/getopt.1.adoc
@@ -59,6 +59,9 @@ Test if your *getopt*(1) is this enhanced version or an old version. This genera
 *-u*, *--unquoted*::
 Do not quote the output. Note that whitespace and special (shell-dependent) characters can cause havoc in this mode (like they do with other *getopt*(1) implementations).
 
+*-U*, *--unknown*::
+Leave unknown options as they are and surpress error messages from *getopt(3)*. Since there is no way to know whether an unknown option requires an argument, a non-option argument that follows the unknown option after a whitespace, is considered an option argument, therefore the argument will be left untouched and printed next to the respective unknown option. To prevent unexpected behavior, short options should be specified individually.
+
 include::man-common/help-version.adoc[]
 
 == PARSING

diff --git a/misc-utils/getopt.c b/misc-utils/getopt.c
index 35737d504727f34ed4175fc174f776d11c30182f..4cab96682178187c57523c20ea51eb1e7ce63853 100644 (file)
--- a/misc-utils/getopt.c
+++ b/misc-utils/getopt.c
@@ -77,6 +77,8 @@
 #define NON_OPT 1
 /* LONG_OPT is the code that is returned when a long option is found. */
 #define LONG_OPT 0
+/* IS_OPT tests whether the token is an option or not. */
+#define IS_OPT(a) (*a == '-')
 
 /* The shells recognized. */
 typedef enum { BASH, TCSH } shell_t;
@@ -89,6 +91,7 @@ struct getopt_control {
        int long_options_length;        /* length of options array */
        int long_options_nr;            /* number of used elements in array */
        bool    compatible,             /* compatibility mode for 'difficult' programs */
+               ignore_unknown,         /* leave unknown options as they are */
                quiet_errors,           /* print errors */
                quiet_output,           /* print output */
                quote;                  /* quote output */
@@ -190,7 +193,7 @@ static int generate_output(struct getopt_control *ctl, char *argv[], int argc)
        int longindex;
        const char *charptr;
 
-       if (ctl->quiet_errors)
+       if (ctl->quiet_errors || ctl->ignore_unknown)
                /* No error reporting from getopt(3) */
                opterr = 0;
        /* Reset getopt(3) */
@@ -201,6 +204,13 @@ static int generate_output(struct getopt_control *ctl, char *argv[], int argc)
                 (argc, argv, ctl->optstr,
                  (const struct option *)ctl->long_options, &longindex)))
               != EOF) {
+
+               if (ctl->ignore_unknown && opt == '?' && !getenv("POSIXLY_CORRECT") && !ctl->quiet_output) {
+                       print_normalized(ctl, argv[optind-1]);
+                       if ((optind <= argc-1) && !IS_OPT(argv[optind])) {
+                               print_normalized(ctl, argv[optind++]);
+                       }
+               }
                /* Given that these two characters are returned by the getopt(3) routines 
                 * to distinguish between two distinct internal error states, they should
                 * not be used as option characters.
@@ -270,7 +280,7 @@ static void add_longopt(struct getopt_control *ctl, const char *name, int has_ar
                ctl->long_options[nr].val = ctl->long_options_nr;
                ctl->long_options[nr].name = xstrdup(name);
        } else {
-               /* lets use add_longopt(ct, NULL, 0) to terminate the array */
+               /* lets use add_longopt(ctl, NULL, 0) to terminate the array */
                ctl->long_options[nr].name = NULL;
                ctl->long_options[nr].has_arg = 0;
                ctl->long_options[nr].flag = NULL;
@@ -361,6 +371,7 @@ static void __attribute__((__noreturn__)) usage(void)
        fputs(_(" -s, --shell <shell>           set quoting conventions to those of <shell>\n"), stdout);
        fputs(_(" -T, --test                    test for getopt(1) version\n"), stdout);
        fputs(_(" -u, --unquoted                do not quote the output\n"), stdout);
+       fputs(_(" -U, --unknown                 leave unknown options as they are and disable getopt(3) error messages\n"), stdout);
        fputs(USAGE_SEPARATOR, stdout);
        fprintf(stdout, USAGE_HELP_OPTIONS(31));
        fprintf(stdout, USAGE_MAN_TAIL("getopt(1)"));
@@ -376,7 +387,7 @@ int main(int argc, char *argv[])
        int opt;
 
        /* Stop scanning as soon as a non-option argument is found! */
-       static const char *shortopts = "+ao:l:n:qQs:TuhV";
+       static const char *shortopts = "+ao:l:n:qQs:TuUhV";
        static const struct option longopts[] = {
                {"options", required_argument, NULL, 'o'},
                {"longoptions", required_argument, NULL, 'l'},
@@ -385,6 +396,7 @@ int main(int argc, char *argv[])
                {"shell", required_argument, NULL, 's'},
                {"test", no_argument, NULL, 'T'},
                {"unquoted", no_argument, NULL, 'u'},
+               {"unknown", no_argument, NULL, 'U'},
                {"help", no_argument, NULL, 'h'},
                {"alternative", no_argument, NULL, 'a'},
                {"name", required_argument, NULL, 'n'},
@@ -453,7 +465,9 @@ int main(int argc, char *argv[])
                case 'u':
                        ctl.quote = 0;
                        break;
-
+               case 'U':
+                       ctl.ignore_unknown = 1;
+                       break;
                case 'V':
                        print_version(EXIT_SUCCESS);
                case '?':