exec: initHEAD1.0master

2 files changed, 119 insertions, 0 deletions

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..14ffa64
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,14 @@
+PREFIX ?= /usr/local
+BINDIR ?= $(PREFIX)/bin
+CACHEDIR ?= $(PWD)
+
+.PHONY: all
+all: $(CACHEDIR)/exec
+
+.PHONY: install
+install: $(CACHEDIR)/exec
+	mkdir -p $(BINDIR)
+	cp $(CACHEDIR)/exec $(BINDIR)/
+
+$(CACHEDIR)/%: %.c
+	gcc -Wall -Os -o $@ $<
diff --git a/exec.c b/exec.c
new file mode 100644
index 0000000..739ae74
--- /dev/null
+++ b/exec.c
@@ -0,0 +1,105 @@
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+static void usage(const char *progname) {
+    fprintf(stderr, "Usage: %s [-n name] COMMAND [ARGS...]\n", progname);
+}
+
+int main(int argc, char *argv[]) {
+    int opt;
+    char *cmd_name = NULL;
+
+    // Parse options
+    while ((opt = getopt(argc, argv, "n:")) != -1) {
+        switch (opt) {
+            case 'n':
+                cmd_name = optarg;
+                break;
+            case '?':
+                usage(argv[0]);
+                return 1;
+        }
+    }
+
+    // Remaining args are COMMAND [ARGS...]
+    if (optind >= argc) {
+        usage(argv[0]);
+        return 1;
+    }
+
+    char *command = argv[optind];
+    char *final_argv0 = cmd_name ? cmd_name : command;
+
+    // Prepare new argv for execvp
+    int new_argc = argc - optind;
+    char *new_argv[argc + 1];
+
+    new_argv[0] = final_argv0;
+    for (int i = 1; i < new_argc; i++) {
+        new_argv[i] = argv[optind + i];
+    }
+    new_argv[new_argc] = NULL;
+
+    execvp(command, new_argv);
+    perror("execvp");
+    return 1;
+}
+
+//#define _GNU_SOURCE
+//#include <stdio.h>
+//#include <stdlib.h>
+//#include <string.h>
+//#include <unistd.h>
+//#include <getopt.h>
+//
+//Int main(int argc, char *argv[]) {
+//    char *command_name = NULL;
+//
+//    // Define long options
+//    static struct option long_options[] = {
+//        {"name", required_argument, 0, 'n'},
+//        {0, 0, 0, 0}
+//    };
+//
+//    // Parse options
+//    int opt_index = 0;
+//    int c;
+//    while ((c = getopt_long(argc, argv, "n:", long_options, &opt_index)) != -1) {
+//        switch (c) {
+//            case 'n':
+//                command_name = optarg;
+//                break;
+//            default:
+//                fprintf(stderr, "Usage: %s --name=NEW_NAME COMMAND [ARGS...]\n", argv[0]);
+//                return 1;
+//        }
+//    }
+//
+//    if (!command_name || optind >= argc) {
+//        fprintf(stderr, "Usage: %s --name=NEW_NAME COMMAND [ARGS...]\n", argv[0]);
+//        return 1;
+//    }
+//
+//    // Construct new argv with custom argv[0]
+//    int new_argc = argc - optind + 1;
+//    char **new_argv = malloc(sizeof(char *) * (new_argc + 1));
+//    if (!new_argv) {
+//        perror("malloc failed");
+//        return 1;
+//    }
+//
+//    new_argv[0] = command_name;
+//    for (int i = 0; i < argc - optind; ++i) {
+//        new_argv[i + 1] = argv[optind + i];
+//    }
+//    new_argv[new_argc] = NULL;
+//
+//    // Exec the command
+//    execvp(new_argv[0], new_argv);
+//
+//    // If we’re here, exec failed
+//    perror("execvp failed");
+//    free(new_argv);
+//    return 1;
+//}