Implements getopt for avr

cpu/atmega_common/getopt.c

@@ -0,0 +1,162 @@
+/*
+ * Copyright (C) 2018 Viraj Sahai <vsahai@usc.edu, virajsahai32@gmail.com>
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser General
+ * Public License v2.1. See the file LICENSE in the top level directory for more
+ * details.
+ */
+
+/**
+ * @ingroup     cpu_atmega_common
+ * @{
+ *
+ * @file        getopt.c
+ * @brief       Implementation of getopt lib.
+ *
+ *
+ * @author      Viraj Sahai <vsahai@usc.edu, virajsahai32@gmail.com>
+ *
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include "getopt.h"
+
+char *optarg;
+int optind = 1, opterr = 1, optopt;
+
+int getopt(int argc, char *const argv[], const char *optstring)
+{
+    char *loc_optstr = NULL;
+    char *loc_argvptr = NULL;
+    char opt;
+
+    optarg = NULL;
+
+    if (optind < 1 || optind >= argc) {
+        return -1;
+    }
+
+    if (*argv[optind] != '-' || !(argv[optind] + 1) || *(argv[optind] + 1) == '\0') {
+        return -1;
+    }
+
+    if (*(argv[optind] + 1) == '-') {
+        return -1;
+    }
+
+    opt = *(argv[optind] + 1);
+    loc_optstr = strchr(optstring, (int)opt);
+
+    if (loc_optstr == NULL) {
+        if (opterr && optstring[0] != ':') {
+            fprintf(stderr, "%s: unknown option -%c\n", argv[0], opt);
+        }
+        optopt = opt;
+        return '?';
+    }
+
+    if ((argv[optind] + 2) && *(argv[optind] + 2) != '\0') {
+        loc_argvptr = argv[optind] + 2;
+    }
+
+    ++optind;
+    ++loc_optstr;
+
+    if (*loc_optstr == ':') {
+        ++loc_optstr;
+
+        if (*loc_optstr == ':') {
+            if (loc_argvptr != NULL) {
+                optarg = loc_argvptr;
+            }
+        }
+        else {
+            if (loc_argvptr != NULL) {
+                optarg = loc_argvptr;
+            }
+            else {
+                if (optind < argc && *(argv[optind]) != '-') {
+                    optarg = argv[optind++];
+                }
+                else {
+                    if (opterr && optstring[0] != ':') {
+                        fprintf(stderr, "%s: missing argument for -%c\n", argv[0], opt);
+                    }
+                    if (optstring[0] == ':') {
+                        return ':';
+                    }
+                    return '?';
+                }
+            }
+        }
+    }
+    return opt;
+}
+
+int getopt_r(int argc, char *const argv[], const char *optstring, opt_t *r)
+{
+    char *loc_optstr = NULL;
+    char *loc_argvptr = NULL;
+    char opt;
+
+    if (r->optind < 1 || r->optind >= argc) {
+        return -1;
+    }
+
+    if (*argv[r->optind] != '-' || !(argv[r->optind] + 1) || *(argv[r->optind] + 1) == '\0') {
+        return -1;
+    }
+
+    if (*(argv[r->optind] + 1) == '-') {
+        return -1;
+    }
+
+    opt = *(argv[r->optind] + 1);
+    loc_optstr = strchr(optstring, (int)opt);
+
+    if (loc_optstr == NULL) {
+        if (r->opterr && optstring[0] != ':') {
+            fprintf(stderr, "%s: unknown option -%c\n", argv[0], opt);
+        }
+        r->optopt = opt;
+        return '?';
+    }
+
+    if ((argv[r->optind] + 2) && *(argv[r->optind] + 2) != '\0') {
+        loc_argvptr = argv[r->optind] + 2;
+    }
+
+    ++r->optind;
+    ++loc_optstr;
+
+    if (*loc_optstr == ':') {
+        ++loc_optstr;
+
+        if (*loc_optstr == ':') {
+            if (loc_argvptr != NULL) {
+                r->optarg = loc_argvptr;
+            }
+        }
+        else {
+            if (loc_argvptr != NULL) {
+                r->optarg = loc_argvptr;
+            }
+            else {
+                if (r->optind < argc && *(argv[r->optind]) != '-') {
+                    r->optarg = argv[r->optind++];
+                }
+                else {
+                    if (r->opterr && optstring[0] != ':') {
+                        fprintf(stderr, "%s: missing argument for -%c\n", argv[0], opt);
+                    }
+                    if (optstring[0] == ':') {
+                        return ':';
+                    }
+                    return '?';
+                }
+            }
+        }
+    }
+    return opt;
+}

cpu/atmega_common/include/getopt.h

@@ -0,0 +1,93 @@
+/*
+ * Copyright (C) 2018 Viraj Sahai <vsahai@usc.edu, virajsahai32@gmail.com>
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser General
+ * Public License v2.1. See the file LICENSE in the top level directory for more
+ * details.
+ */
+
+/**
+ * @ingroup     cpu_atmega_common
+ * @{
+ *
+ * @file        header
+ * @brief       Implementation of getopt lib.
+ *
+ * This implements the getopt() and getopt_r() functionality.
+ * getopt_r() has a few caveats, make sure to use it correctly.
+ *
+ * @author      Viraj Sahai <vsahai@usc.edu, virajsahai32@gmail.com>
+ *
+ */
+
+#ifndef GETOPT_H
+#define GETOPT_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief Used to implement a MT safe re-entrant version of getopt().
+ *
+ * User can set error reporting on or off by setting opterr to 0 or 1.
+ * Care must be taken to ensure that optind is initialized to atleast 1.
+ * Use INIT_OPT_T or INIT_OPT_T_PTR for initialization.
+ * Arguments of the option will be returned in optarg.
+ */
+typedef struct {
+    char *optarg;
+    int optind;
+    int opterr;
+    int optopt;
+} opt_t;
+
+/**
+ * @brief Used to initialize opt_t* variable for use with getopt_r().
+ *
+ * Ensures that required variables pointed by opt_t* are initialized to prevent
+ * undefined behavior when using getopt_r().
+ */
+#define INIT_OPT_T_PTR &(opt_t){ NULL, 1, 1, -1 }
+
+/**
+ * @brief Used to initialize opt_t variable for use with getopt_r().
+ *
+ * Ensures that required variables in opt_t are initialized to prevent
+ * undefined behavior when using getopt_r().
+ */
+#define INIT_OPT_T { NULL, 1, 1, -1 }
+
+extern char *optarg;
+extern int optind, opterr, optopt;
+
+/**
+ * @brief      Non re-entrant version of getopt.
+ *
+ * @param[in]  argc           The count of the number of arguments.
+ * @param[in]  argv           The array containing all the arguments.
+ * @param[in]  optstring      The string of expected options.
+ *
+ * @return ASCII value of the option if option was successfully found.
+ *         '?' or ':' when unknown option is found or argument is missing.
+ */
+int getopt(int argc, char *const argv[], const char *optstring);
+
+/**
+ * @brief      Re-entrant version of getopt.
+ *
+ * @param[in]  argc           The count of the number of arguments.
+ * @param[in]  argv           The array containing all the arguments.
+ * @param[in]  optstring      The string of expected options.
+ * @param[out] r              The per call struct for holding return args and other options.
+ *
+ * @return ASCII value of the option if option was successfully found.
+ *         '?' or ':' when unknown option is found or argument is missing.
+ */
+int getopt_r(int argc, char *const argv[], const char *optstring, opt_t *r);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GETOPT_H */