1 files changed, 232 insertions, 0 deletions
diff --git a/command/chmod.c b/command/chmod.c
new file mode 100644
index 0000000..9e2972e
--- /dev/null
+++ b/command/chmod.c
@@ -0,0 +1,232 @@
+#include "args.h"
+#include "command.h"
+#include "lslib.h"
+
+#include <stdlib.h>
+#include <sys/types.h>
+#include <pwd.h>
+#include <unistd.h>
+#include <dirent.h>
+#include <errno.h>
+#include <string.h>
+
+enum method {
+    ADD,
+    SUB,
+    SET
+};
+
+static struct {
+    bool recurse;
+    bool list_changed;
+    bool verbose;
+    bool quiet;
+    enum method method;
+    mode_t mode;
+} flags;
+
+static void help (void) {
+    printf("Usage: chmod [-Rcvf] MODE[,MODE]... FILE...\n\n");
+    printf("MODE is octal number (bit pattern sstrwxrwxrwx) or [ugoa]{+|-|=}[rwxXst]\n\n");
+    printf("\t-R\tRecurse\n");
+	printf("\t-c\tList changed files\n");
+	printf("\t-v\tVerbose\n");
+	printf("\t-f\tHide errors\n");
+}
+
+static int short_arg(char c, char* next) {
+    UNUSED(next);
+    switch (c) {
+        case 'R':
+            flags.recurse = true;
+            break;
+        case 'c':
+            flags.list_changed = true;
+            break;
+        case 'v':
+            flags.verbose = true;
+            break;
+        case 'f':
+            flags.quiet = true;
+            break;
+        case 'r':
+        case 'w':
+        case 'x':
+        case 'X':
+        case 't':
+        case 's':
+            return ARG_IGNORE;
+        default:
+            return ARG_INVALID;
+    }
+    return ARG_UNUSED;
+}
+
+static void chmod_file(char* path) {
+    int save;
+    struct stat s;
+    DIR* d;
+    struct dirent* file;
+    mode_t mode = 0;
+
+    save = push_path_buffer(path);
+    
+    if (lstat(get_path_buffer(), &s) < 0) {
+        if (!flags.quiet) {
+            error_s("cannot stat '%s': %s", get_path_buffer(), strerror(errno));
+        }
+        pop_path_buffer(save);
+        return;
+    }
+
+    if (flags.method == SET) {
+        mode = flags.mode;;
+    } else if (flags.method == ADD) {
+        mode = s.st_mode | flags.mode;
+    } else if (flags.method == SUB) {
+        mode = s.st_mode & ~flags.mode;
+    }
+    
+    if (chmod(get_path_buffer(), mode) < 0) {
+        if (!flags.quiet) {
+            error_s("cannot chmod '%s': %s", get_path_buffer(), strerror(errno));
+        }
+        pop_path_buffer(save);
+        return;
+    } else if (flags.list_changed) {
+        printf("chmod: changed '%s' to %o\n", get_path_buffer(), mode);
+    }
+
+    if (!flags.recurse) {
+        pop_path_buffer(save);
+        return;
+    }
+
+    if (!S_ISDIR(s.st_mode)) {
+        pop_path_buffer(save);
+        return;
+    }
+
+    d = opendir(get_path_buffer());
+    if (d == NULL) {
+        if (!flags.quiet) {
+            error_s("cannot open dir '%s': %s", get_path_buffer(), strerror(errno));
+        }
+        pop_path_buffer(save);
+        return;
+    }
+
+    while ((file = readdir(d)) != NULL) {
+        if (is_dot_dir(file->d_name)) continue;
+        chmod_file(file->d_name);
+    }
+    
+    closedir(d);
+    pop_path_buffer(save);
+}
+
+static mode_t parse_mode(char** input) {
+    mode_t mode = 00000;
+    char* str = *input;
+
+    switch (*str) {
+        case '=':
+            flags.method = SET;
+            break;
+        case '+':
+            flags.method = ADD;
+            break;
+        case '-':
+            flags.method = SUB;
+            break;
+        default:
+            flags.method = SET;
+            mode = get_mode(str);
+            goto end;
+    }
+
+next:
+    str++;
+    switch (*str) {
+        case 'r':
+            mode |= 00444;
+            goto next;
+        case 'w':
+            mode |= 00200;
+            goto next;
+        case 'x':
+            mode |= 00111;
+            goto next;
+        case 'X':
+            mode |= 00000;
+            goto next;
+        case 's':
+            mode |= 06000;
+            goto next;
+        case 't':
+            mode |= 01000;
+            goto next;
+        case '\0':
+        case ',':
+            goto end;
+        default:
+            error("invalid option: %c", *str);
+    }
+
+end:
+    while (true) {
+        
+        if (*str == '\0') {
+            *input = NULL;
+            break;
+        }
+
+        if (*str == ',') {
+            *input = ++str;
+            break;
+        }
+
+        str++;
+    }
+
+    return mode;
+}
+
+COMMAND(chmod_cmd) {
+    
+    int start, i;
+    
+    flags.recurse = false;
+    flags.list_changed = false;
+    flags.verbose = false;
+    flags.quiet = false;
+    flags.mode = 0;
+
+    start = parse_args(argc, argv, help, short_arg, NULL);
+
+    if (argc - start < 1) {
+        if (!flags.quiet) {
+            error("no mode provided");
+        } else {
+            return EXIT_FAILURE;
+        }
+    }
+
+    do {
+        flags.mode |= parse_mode(&argv[start]);
+    } while (argv[start] != NULL);
+
+    if (argc - start < 2) {
+        if (!flags.quiet) {
+            error("no files passed");
+        } else {
+            return EXIT_FAILURE;
+        }
+    }
+
+    for (i = start + 1; i < argc; i++) {
+        chmod_file(argv[i]);
+    }
+
+    return EXIT_SUCCESS;
+}