tools: Add mailutil groundwork

Signed-off-by: Ian Moffett <ian@mirocom.org>

Makefile

@@ -4,7 +4,7 @@
 #
 
 .PHONY: all
-all: bin libremail endpoint
+all: bin libremail tools endpoint
 
 .PHONY: bin
 bin:
@@ -14,6 +14,10 @@ bin:
 libremail:
 	cd libremail/; make
 
+.PHONY: tools
+tools:
+	cd tools/; make
+
 .PHONY: endpoint
 endpoint:
 	cd endpoint/; make
@@ -21,3 +25,5 @@ endpoint:
 .PHONY: clean
 clean:
 	cd endpoint/; make clean
+	cd libremail/; make clean
+	cd tools/; make clean

tools/Makefile

@@ -0,0 +1,12 @@
+#
+# Copyright (c) 2026, Chloe Moffett
+# Provided under the BSD-3 clause
+#
+
+.PHONY: all
+all:
+	cd mailutil/; make
+
+.PHONY: clean
+clean:
+	cd mailutil/; make clean

tools/mailutil/Makefile

@@ -0,0 +1,34 @@
+#
+# Copyright (c) 2026, Chloe Moffett
+# Provided under the BSD-3 clause
+#
+
+CFILES = $(shell find . -name "*.c")
+OFILES = $(CFILES:.c=.o)
+OFILES += $(shell find ../../libremail/ -name "*.o")
+DFILES = $(CFILES:.c=.d)
+
+OUTPUT = ../../bin/mailutil
+CC = gcc
+
+CFLAGS = 				\
+	-Wall				\
+	-pedantic			\
+	-MMD				\
+	-Iinc				\
+	-I../../libremail/inc
+
+.PHONY: all
+all: $(OUTPUT) $(OFILES)
+
+.PHONY: $(OUTPUT)
+$(OUTPUT): $(OFILES)
+	$(CC) $^ -o $@
+
+-include $(DFILES)
+%.o: %.c
+	$(CC) -c $< $(CFLAGS) -o $@
+
+.PHONY: clean
+clean:
+	rm -f $(OFILES) $(DFILES)

tools/mailutil/core/mailutil.c

@@ -0,0 +1,160 @@
+/*
+ * Copyright (c) 2026, Chloe Moffett
+ * Provided under the BSD-3 clause
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <unistd.h>
+#include "libremail/file.h"
+
+/* Maximum command components */
+#define CMD_MAX_CNP 6
+
+/* Mailutil version */
+#define MAILUTIL_VERSION "0.0.1"
+
+#define DEFAULT_MAILBOX_MODE 0600
+
+/*
+ * Macro used to assert that the command list count is not
+ * zero to avoid code duplication.
+ */
+#define ASSERT_COUNT(CNT)                           \
+    if ((CNT) == 0) {                               \
+        printf("error: cmdlist count is zero\n");   \
+        return -1;                                  \
+    }
+
+/*
+ * Macro used to ensure that overflows don't happen
+ */
+#define ASSERT_COUNT_N(CNT, MAX)                            \
+    if ((CNT) < (MAX)) {                                    \
+        printf("error: too few parameters for command\n");  \
+        return -1;                                          \
+    }
+
+static void
+help(void)
+{
+    printf("usage: ./mailutil [... flags] [verb] [...]\n");
+    printf("... [-h] Display this help menu\n");
+    printf("... [-v] Display the version\n");
+}
+
+static void
+version(void)
+{
+    printf("Version v%s\n", MAILUTIL_VERSION);
+}
+
+/*
+ * Parse a "mailbox create" command
+ *
+ * @cmdlist: Command list to parse
+ * @count:   Number of entries inside command list
+ *
+ * Returns zero on success
+ */
+static int
+cmd_mailbox_create(const char *cmdlist[CMD_MAX_CNP], size_t count)
+{
+    char pathbuf[64];
+
+    ASSERT_COUNT_N(count, 3);
+
+    snprintf(pathbuf, sizeof(pathbuf), "/var/mail/%s", cmdlist[2]);
+
+    /* Create the mailbox */
+    if (try_mkdir(pathbuf, DEFAULT_MAILBOX_MODE) < 0) {
+        printf("fatal: failed to create mailbox\n");
+        perror("try_mkdir");
+        return -1;
+    }
+
+    printf("created mailbox '%s' @ %s\n",
+        cmdlist[2], pathbuf);
+
+    return 0;
+}
+
+/*
+ * Parse a "mailbox" command
+ *
+ * @cmdlist: Command list to parse
+ * @count:   Number of entries inside command list
+ *
+ * Returns zero on success
+ */
+static int
+cmd_mailbox(const char *cmdlist[CMD_MAX_CNP], size_t count)
+{
+    ASSERT_COUNT_N(count, 2);
+
+    if (strcmp(cmdlist[1], "create") == 0) {
+        return cmd_mailbox_create(cmdlist, count);
+    }
+
+    printf("error: bad parameter\n");
+    return -1;
+}
+
+/*
+ * Parse a command given from the command line
+ *
+ * @cmdlist: Command list to parse
+ * @count:   Number of entries inside command list
+ *
+ * Returns zero on success
+ */
+static int
+parse_cmd(const char *cmdlist[CMD_MAX_CNP], size_t count)
+{
+    ASSERT_COUNT(count);
+
+    if (strcmp(cmdlist[0], "mailbox") == 0) {
+        return cmd_mailbox(cmdlist, count);
+    }
+
+    printf("error: bad parameter\n");
+    return -1;
+}
+
+int
+main(int argc, char **argv)
+{
+    int opt;
+    const char *cmdlist[CMD_MAX_CNP];
+    size_t cmdlist_i = 0;
+
+    if (argc < 2) {
+        printf("fatal: too few arguments\n");
+        help();
+        return -1;
+    }
+
+    while ((opt = getopt(argc, argv, "hv")) != -1) {
+        switch (opt) {
+        case 'h':
+            help();
+            return -1;
+        case 'v':
+            version();
+            return 0;
+        }
+    }
+
+    /* Accumulate command line parameters */
+    while (optind < argc) {
+        cmdlist[cmdlist_i++] = argv[optind++];
+    }
+
+    if (parse_cmd(cmdlist, cmdlist_i) < 0) {
+        printf("fatal: error parsing command list\n");
+        return -1;
+    }
+
+    return 0;
+}