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diff --git a/man-pages-posix-2003/man1p/umask.1p b/man-pages-posix-2003/man1p/umask.1p new file mode 100644 index 0000000..c8a644c --- /dev/null +++ b/man-pages-posix-2003/man1p/umask.1p @@ -0,0 +1,315 @@ +.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved +.TH "UMASK" 1P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual" +.\" umask +.SH PROLOG +This manual page is part of the POSIX Programmer's Manual. +The Linux implementation of this interface may differ (consult +the corresponding Linux manual page for details of Linux behavior), +or the interface may not be implemented on Linux. +.SH NAME +umask \- get or set the file mode creation mask +.SH SYNOPSIS +.LP +\fBumask\fP \fB[\fP\fB-S\fP\fB][\fP\fImask\fP\fB]\fP +.SH DESCRIPTION +.LP +The \fIumask\fP utility shall set the file mode creation mask of the +current shell execution environment (see \fIShell Execution Environment\fP +) to the value specified by the \fImask\fP operand. This mask +shall affect the initial value of the file permission bits of subsequently +created files. If \fIumask\fP is called in a subshell +or separate utility execution environment, such as one of the following: +.sp +.RS +.nf + +\fB(umask 002) +nohup umask ... +find . -exec umask ... \\; +\fP +.fi +.RE +.LP +it shall not affect the file mode creation mask of the caller's environment. +.LP +If the \fImask\fP operand is not specified, the \fIumask\fP utility +shall write to standard output the value of the invoking +process' file mode creation mask. +.SH OPTIONS +.LP +The \fIumask\fP utility shall conform to the Base Definitions volume +of IEEE\ Std\ 1003.1-2001, Section 12.2, Utility Syntax Guidelines. +.LP +The following option shall be supported: +.TP 7 +\fB-S\fP +Produce symbolic output. +.sp +.LP +The default output style is unspecified, but shall be recognized on +a subsequent invocation of \fIumask\fP on the same system +as a \fImask\fP operand to restore the previous file mode creation +mask. +.SH OPERANDS +.LP +The following operand shall be supported: +.TP 7 +\fImask\fP +A string specifying the new file mode creation mask. The string is +treated in the same way as the \fImode\fP operand described +in the EXTENDED DESCRIPTION section for \fIchmod\fP. +.LP +For a \fIsymbolic_mode\fP value, the new value of the file mode creation +mask shall be the logical complement of the file +permission bits portion of the file mode specified by the \fIsymbolic_mode\fP +string. +.LP +In a \fIsymbolic_mode\fP value, the permissions \fIop\fP characters +\fB'+'\fP and \fB'-'\fP shall be interpreted +relative to the current file mode creation mask; \fB'+'\fP shall cause +the bits for the indicated permissions to be cleared in +the mask; \fB'-'\fP shall cause the bits for the indicated permissions +to be set in the mask. +.LP +The interpretation of \fImode\fP values that specify file mode bits +other than the file permission bits is unspecified. +.LP +In the octal integer form of \fImode\fP, the specified bits are set +in the file mode creation mask. +.LP +The file mode creation mask shall be set to the resulting numeric +value. +.LP +The default output of a prior invocation of \fIumask\fP on the same +system with no operand also shall be recognized as a +\fImask\fP operand. +.sp +.SH STDIN +.LP +Not used. +.SH INPUT FILES +.LP +None. +.SH ENVIRONMENT VARIABLES +.LP +The following environment variables shall affect the execution of +\fIumask\fP: +.TP 7 +\fILANG\fP +Provide a default value for the internationalization variables that +are unset or null. (See the Base Definitions volume of +IEEE\ Std\ 1003.1-2001, Section 8.2, Internationalization Variables +for +the precedence of internationalization variables used to determine +the values of locale categories.) +.TP 7 +\fILC_ALL\fP +If set to a non-empty string value, override the values of all the +other internationalization variables. +.TP 7 +\fILC_CTYPE\fP +Determine the locale for the interpretation of sequences of bytes +of text data as characters (for example, single-byte as +opposed to multi-byte characters in arguments). +.TP 7 +\fILC_MESSAGES\fP +Determine the locale that should be used to affect the format and +contents of diagnostic messages written to standard +error. +.TP 7 +\fINLSPATH\fP +Determine the location of message catalogs for the processing of \fILC_MESSAGES +\&.\fP +.sp +.SH ASYNCHRONOUS EVENTS +.LP +Default. +.SH STDOUT +.LP +When the \fImask\fP operand is not specified, the \fIumask\fP utility +shall write a message to standard output that can later +be used as a \fIumask\fP \fImask\fP operand. +.LP +If \fB-S\fP is specified, the message shall be in the following format: +.sp +.RS +.nf + +\fB"u=%s,g=%s,o=%s\\n", <\fP\fIowner permissions\fP\fB>, <\fP\fIgroup permissions\fP\fB>, + <\fP\fIother permissions\fP\fB> +\fP +.fi +.RE +.LP +where the three values shall be combinations of letters from the set +{ \fIr\fP, \fIw\fP, \fIx\fP}; the presence of a letter +shall indicate that the corresponding bit is clear in the file mode +creation mask. +.LP +If a \fImask\fP operand is specified, there shall be no output written +to standard output. +.SH STDERR +.LP +The standard error shall be used only for diagnostic messages. +.SH OUTPUT FILES +.LP +None. +.SH EXTENDED DESCRIPTION +.LP +None. +.SH EXIT STATUS +.LP +The following exit values shall be returned: +.TP 7 +\ 0 +The file mode creation mask was successfully changed, or no \fImask\fP +operand was supplied. +.TP 7 +>0 +An error occurred. +.sp +.SH CONSEQUENCES OF ERRORS +.LP +Default. +.LP +\fIThe following sections are informative.\fP +.SH APPLICATION USAGE +.LP +Since \fIumask\fP affects the current shell execution environment, +it is generally provided as a shell regular built-in. +.LP +In contrast to the negative permission logic provided by the file +mode creation mask and the octal number form of the +\fImask\fP argument, the symbolic form of the \fImask\fP argument +specifies those permissions that are left alone. +.SH EXAMPLES +.LP +Either of the commands: +.sp +.RS +.nf + +\fBumask a=rx,ug+w +.sp + +umask 002 +\fP +.fi +.RE +.LP +sets the mode mask so that subsequently created files have their S_IWOTH +bit cleared. +.LP +After setting the mode mask with either of the above commands, the +\fIumask\fP command can be used to write out the current +value of the mode mask: +.sp +.RS +.nf + +\fB$\fP \fBumask +\fP\fB0002\fP +.fi +.RE +.LP +(The output format is unspecified, but historical implementations +use the octal integer mode format.) +.sp +.RS +.nf + +\fB$\fP \fBumask -S +\fP\fBu=rwx,g=rwx,o=rx\fP +.fi +.RE +.LP +Either of these outputs can be used as the mask operand to a subsequent +invocation of the \fIumask\fP utility. +.LP +Assuming the mode mask is set as above, the command: +.sp +.RS +.nf + +\fBumask g-w +\fP +.fi +.RE +.LP +sets the mode mask so that subsequently created files have their S_IWGRP +and S_IWOTH bits cleared. +.LP +The command: +.sp +.RS +.nf + +\fBumask -- -w +\fP +.fi +.RE +.LP +sets the mode mask so that subsequently created files have all their +write bits cleared. Note that \fImask\fP operands +\fB-r\fP, \fB-w\fP, \fB-x\fP or anything beginning with a hyphen, +must be preceded by \fB"--"\fP to keep it from being +interpreted as an option. +.SH RATIONALE +.LP +Since \fIumask\fP affects the current shell execution environment, +it is generally provided as a shell regular built-in. If it +is called in a subshell or separate utility execution environment, +such as one of the following: +.sp +.RS +.nf + +\fB(umask 002) +nohup umask ... +find . -exec umask ... \\; +\fP +.fi +.RE +.LP +it does not affect the file mode creation mask of the environment +of the caller. +.LP +The description of the historical utility was modified to allow it +to use the symbolic modes of \fIchmod\fP. The \fB-s\fP option used +in early proposals was changed to \fB-S\fP because \fB-s\fP +could be confused with a \fIsymbolic_mode\fP form of mask referring +to the S_ISUID and S_ISGID bits. +.LP +The default output style is implementation-defined to permit implementors +to provide migration to the new symbolic style at the +time most appropriate to their users. A \fB-o\fP flag to force octal +mode output was omitted because the octal mode may not be +sufficient to specify all of the information that may be present in +the file mode creation mask when more secure file access +permission checks are implemented. +.LP +It has been suggested that trusted systems developers might appreciate +ameliorating the requirement that the mode mask +"affects" the file access permissions, since it seems access control +lists might replace the mode mask to some degree. The +wording has been changed to say that it affects the file permission +bits, and it leaves the details of the behavior of how they +affect the file access permissions to the description in the System +Interfaces volume of IEEE\ Std\ 1003.1-2001. +.SH FUTURE DIRECTIONS +.LP +None. +.SH SEE ALSO +.LP +\fIShell Command Language\fP, \fIchmod\fP, the System +Interfaces volume of IEEE\ Std\ 1003.1-2001, \fIumask\fP() +.SH COPYRIGHT +Portions of this text are reprinted and reproduced in electronic form +from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology +-- Portable Operating System Interface (POSIX), The Open Group Base +Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of +Electrical and Electronics Engineers, Inc and The Open Group. In the +event of any discrepancy between this version and the original IEEE and +The Open Group Standard, the original IEEE and The Open Group Standard +is the referee document. The original Standard can be obtained online at +http://www.opengroup.org/unix/online.html . |