1 files changed, 66 insertions, 0 deletions
diff --git a/checkenv/checkenv.c b/checkenv/checkenv.c
new file mode 100644
index 0000000..d2d6c57
--- /dev/null
+++ b/checkenv/checkenv.c
@@ -0,0 +1,66 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+static void
+help(void)
+{
+    printf("usage: ./checkenv <ENV>:<...>:<...>\n");
+    printf("[-h]    Display this help menu\n");
+}
+
+static int
+check_envs(const char *envlist)
+{
+    char *p, *tok;
+    char *env;
+
+    p = strdup(envlist);
+    if (p == NULL) {
+        printf("fatal: out of memory\n");
+        return -1;
+    }
+
+    tok = strtok(p, ":");
+    while (tok != NULL) {
+        if ((env = getenv(tok)) == NULL) {
+            printf("env '%s' not set\n", tok);
+            return -1;
+        }
+        tok = strtok(NULL, ":");
+    }
+
+    return 0;
+}
+
+int
+main(int argc, char **argv)
+{
+    int opt;
+    char *envlist;
+    int error;
+
+    if (argc < 2) {
+        printf("fatal: too few arguments\n");
+        help();
+        return -1;
+    }
+
+    while ((opt = getopt(argc, argv, "h")) != -1) {
+        switch (opt) {
+        case 'h':
+            help();
+            return -1;
+        }
+    }
+
+    while (optind < argc) {
+        envlist = argv[optind++];
+        if ((error = check_envs(envlist)) < 0) {
+            return error;
+        }
+    }
+
+    return 0;
+}