feat: watch: init

package/c/watch/main.c

@@ -0,0 +1,152 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/select.h>
+#include <time.h>
+#include <ctype.h>
+#include <limits.h>
+
+#ifndef PATH_MAX
+#define PATH_MAX 4096
+#endif
+
+#define MAX_FILES 1024
+#define POLL_INTERVAL_MS 100  // milliseconds
+
+void print_usage(const char *prog_name) {
+    fprintf(stderr, "Usage: %s <command> <file1> [file2] ...\n", prog_name);
+    fprintf(stderr, "   or: find <pattern> | %s <command>\n", prog_name);
+    exit(EXIT_FAILURE);
+}
+
+struct file_info {
+    char *path;
+    time_t last_mtime;
+    struct stat st;
+};
+
+int check_file_modified(struct file_info *file) {
+    struct stat new_st;
+    if (stat(file->path, &new_st) != 0) {
+        perror("stat");
+        return -1;
+    }
+
+    // Check if file was modified
+    if (new_st.st_mtime != file->st.st_mtime) {
+        file->st = new_st;
+        return 1;
+    }
+    return 0;
+}
+
+int main(int argc, char *argv[]) {
+    if (argc < 2) {
+        print_usage(argv[0]);
+    }
+
+    char *command = argv[1];
+    struct file_info files[MAX_FILES];
+    int num_files = 0;
+
+    // Check if we're getting input from stdin (find command)
+    if (!isatty(fileno(stdin))) {
+        // Read files from stdin
+        char line[PATH_MAX];
+        while (fgets(line, sizeof(line), stdin) && num_files < MAX_FILES) {
+            // Remove newline and any whitespace
+            line[strcspn(line, "\n")] = 0;
+            char *end = line + strlen(line) - 1;
+            while (end >= line && isspace(*end)) end--;
+            *(end + 1) = 0;
+            
+            if (strlen(line) > 0) {
+                files[num_files].path = strdup(line);
+                if (!files[num_files].path) {
+                    perror("strdup");
+                    exit(EXIT_FAILURE);
+                }
+                if (stat(files[num_files].path, &files[num_files].st) != 0) {
+                    perror("stat");
+                    fprintf(stderr, "Skipping invalid path: %s\n", line);
+                    free(files[num_files].path);
+                    continue;
+                }
+                num_files++;
+            }
+        }
+    } else {
+        // No stdin input, use command line arguments
+        if (argc < 3) {
+            print_usage(argv[0]);
+        }
+        for (int i = 2; i < argc && num_files < MAX_FILES; i++) {
+            files[num_files].path = strdup(argv[i]);
+            if (!files[num_files].path) {
+                perror("strdup");
+                exit(EXIT_FAILURE);
+            }
+            if (stat(files[num_files].path, &files[num_files].st) != 0) {
+                perror("stat");
+                fprintf(stderr, "Skipping invalid path: %s\n", argv[i]);
+                free(files[num_files].path);
+                continue;
+            }
+            num_files++;
+        }
+    }
+
+    if (num_files == 0) {
+        fprintf(stderr, "No files to watch\n");
+        exit(EXIT_FAILURE);
+    }
+
+    // Print the files we're watching
+    fprintf(stderr, "Watching %d files:\n", num_files);
+    for (int i = 0; i < num_files; i++) {
+        fprintf(stderr, "  %s\n", files[i].path);
+    }
+
+    fprintf(stderr, "Waiting for file modifications...\n");
+
+    struct timeval tv;
+    tv.tv_sec = 0;
+    tv.tv_usec = POLL_INTERVAL_MS * 1000;  // Convert to microseconds
+
+    while (1) {
+        // Use select to wait for the specified interval
+        select(0, NULL, NULL, NULL, &tv);
+
+        int any_modified = 0;
+        for (int i = 0; i < num_files; i++) {
+            int modified = check_file_modified(&files[i]);
+            if (modified > 0) {
+                fprintf(stderr, "File modified: %s\n", files[i].path);
+                any_modified = 1;
+            } else if (modified < 0) {
+                fprintf(stderr, "Error checking file: %s\n", files[i].path);
+            }
+        }
+
+        if (any_modified) {
+            fprintf(stderr, "Executing command: %s\n", command);
+            int res = system(command);
+            if (res != 0) {
+                perror("system");
+                exit(EXIT_FAILURE);
+            }
+        }
+
+        // Reset timeout for next iteration
+        tv.tv_sec = 0;
+        tv.tv_usec = POLL_INTERVAL_MS * 1000;
+    }
+
+    // Cleanup
+    for (int i = 0; i < num_files; i++) {
+        free(files[i].path);
+    }
+    return 0;
+}