Add some sources

src/common.h

@@ -0,0 +1,13 @@
+#ifndef COMMON_H
+#define COMMON_H
+
+
+#define CONCAT(x,y) _CONCAT(x,y)
+#define _CONCAT(x,y) (x##y)
+
+
+#define TOSTR(x) _TOSTR(x)
+#define _TOSTR(x) (#x)
+
+
+#endif /* COMMON_H */

src/icmd.c

@@ -0,0 +1,65 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+#include "icmd.h"
+#include "common.h"
+
+
+#define ICMDS_SIZE                                  \
+    (sizeof(g_icmds) / sizeof(g_icmds[0]))
+
+#define ICMD(name)                                  \
+    {                                               \
+        .cmd = TOSTR(name),                         \
+        .len = sizeof(TOSTR(name)),                 \
+        .func = CONCAT(icmd_, name),                \
+    }
+
+
+struct icmd g_icmds[] =
+{
+    ICMD(exit),
+    ICMD(cd),
+    ICMD(ls),
+};
+
+
+int
+call_icmds(char *line)
+{
+    size_t i;
+
+    for (i = 0; i < ICMDS_SIZE; i++)
+    {
+        printf("cmp: %s : %s \n", g_icmds[i].cmd, line);
+        if (strncmp(g_icmds[i].cmd, line, g_icmds[i].len) == 0)
+            return g_icmds[i].func(line);
+    }
+
+    return INT_MAX;
+}
+
+
+int
+icmd_exit(char *line)
+{
+    printf("exiting with reason: %s", line);
+    exit(0);
+}
+
+
+int
+icmd_cd(char *line)
+{
+    printf("I'm a cd! line: %s\n", line);
+    return 0;
+}
+
+
+int
+icmd_ls(char *line)
+{
+    printf("I'm a ls! line: %s\n", line);
+    return 1;
+}

src/icmd.h

@@ -0,0 +1,23 @@
+#ifndef ICMD_H
+#define ICMD_H
+
+
+struct icmd
+{
+    char *cmd;
+    int len;
+    int (*func)(char *);
+};
+
+
+/* interface */
+int call_icmds(char *line);
+
+
+/* internal commands as functions */
+int icmd_exit(char *line);
+int icmd_cd(char *line);
+int icmd_ls(char *line);
+
+
+#endif /* ICMD_H */

src/main.c

@@ -0,0 +1,49 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <limits.h>
+#include "icmd.h"
+
+
+/* should be enough */
+#define CMD_LINE_MAX    1024
+#define CMD_PATH_MAX    4096
+
+
+int
+die(char *s)
+{
+    perror(s);
+    exit(-1);
+}
+
+
+int
+main(int argc, char **argv)
+{
+    char line[CMD_LINE_MAX];
+    char cwd[CMD_PATH_MAX];
+    char *pline = line;
+    int ret;
+
+    for (;;)
+    {
+        /* todo: does it really fail? */
+        if (getcwd(cwd, sizeof(cwd)) == NULL)
+            die("getcwd()");
+
+        printf("[%s] ", cwd);
+        fgets(line, sizeof(line), stdin);
+
+        ret = call_icmds(line);
+        if (ret == INT_MAX)
+            puts("no such internal command, going on...");
+        else if (ret == 0)
+            puts("internal command succeded!");
+         else
+            puts("internal command succeded!");
+    }
+
+    return 0;
+}