CHMOD(1L) CHMOD(1L) NNAAMMEE chmod - change the access permissions of files SSYYNNOOPPSSIISS cchhmmoodd [-Rcfv] [--recursive] [--changes] [--silent] [--quiet] [--verbose] [--help] [--version] mode file... DDEESSCCRRIIPPTTIIOONN This manual page documents the GNU version of cchhmmoodd. cchhmmoodd changes the permissions of each given file according to _m_o_d_e, which can be either a symbolic representation of changes to make, or an octal number representing the bit pattern for the new permissions. The format of a symbolic mode is `[ugoa...][[+-=][rwxXstugo...]...][,...]'. Multiple sym- bolic operations can be given, separated by commas. A combination of the letters `ugoa' controls which users' access to the file will be changed: the user who owns it (u), other users in the file's group (g), other users not in the file's group (o), or all users (a). If none of these are given, the effect is as if `a' were given, but bits that are set in the umask are not affected. The operator `+' causes the permissions selected to be added to the existing permissions of each file; `-' causes them to be removed; and `=' causes them to be the only permissions that the file has. The letters `rwxXstugo' select the new permissions for the affected users: read (r), write (w), execute (or access for directories) (x), execute only if the file is a direc- tory or already has execute permission for some user (X), set user or group ID on execution (s), save program text on swap device (t), the permissions that the user who owns the file currently has for it (u), the permissions that other users in the file's group have for it (g), and the permissions that other users not in the file's group have for it (o). A numeric mode is from one to four octal digits (0-7), derived by adding up the bits with values 4, 2, and 1. Any omitted digits are assumed to be leading zeros. The first digit selects the set user ID (4) and set group ID (2) and save text image (1) attributes. The second digit selects permissions for the user who owns the file: read (4), write (2), and execute (1); the third selects permis- sions for other users in the file's group, with the same values; and the fourth for other users not in the file's group, with the same values. cchhmmoodd never changes the permissions of symbolic links; the cchhmmoodd system call cannot change their permissions. This FSF GNU File Utilities 1 CHMOD(1L) CHMOD(1L) is not a problem since the permissions of symbolic links are never used. However, for each symbolic link listed on the command line, cchhmmoodd changes the permissions of the pointed-to file. In contrast, cchhmmoodd ignores symbolic links encountered during recursive directory traversals. OOPPTTIIOONNSS _-_c_, _-_-_c_h_a_n_g_e_s Verbosely describe only files whose permissions actually change. _-_f_, _-_-_s_i_l_e_n_t_, _-_-_q_u_i_e_t Do not print error messages about files whose per- missions cannot be changed. _-_v_, _-_-_v_e_r_b_o_s_e Verbosely describe changed permissions. _-_R_, _-_-_r_e_c_u_r_s_i_v_e Recursively change permissions of directories and their contents. _-_-_h_e_l_p Print a usage message on standard output and exit successfully. _-_-_v_e_r_s_i_o_n Print version information on standard output then exit successfully. FSF GNU File Utilities 2 .