port.html

IEEE 1003.1-2003, Single Unix Specification v3

<h5><a name="tag_04_02_11_01"></a>Unsatisfied Requirements</h5>

<p>The command line interface to individual utilities is as intuitive and consistent as historical practice allows. Work underway
based on graphical user interfaces may be more suitable for novice or occasional users of the system.</p>

<h4><a name="tag_04_02_12"></a>Accomplish Multiple Tasks Simultaneously</h4>

<p>The shell command language offers background processing through the asynchronous list command form; see the Shell and Utilities
volume of IEEE&nbsp;Std&nbsp;1003.1-2001, <a href="../utilities/xcu_chap02.html#tag_02_09">Section 2.9, Shell Commands</a>. The <a
href="../utilities/nohup.html"><i>nohup</i></a> utility makes background processing more robust and usable. The <a href=
"../utilities/kill.html"><i>kill</i></a> utility can terminate background jobs. When the User Portability Utilities option is
supported, the following utilities allow manipulation of jobs: <a href="../utilities/bg.html"><i>bg</i></a>, <a href=
"../utilities/fg.html"><i>fg</i></a>, and <a href="../utilities/jobs.html"><i>jobs</i></a>. Also, if the User Portability Utilities
option is supported, the following can support periodic job scheduling, control, and display: <a href=
"../utilities/at.html"><i>at</i></a>, <a href="../utilities/batch.html"><i>batch</i></a>, <a href=
"../utilities/crontab.html"><i>crontab</i></a>, <a href="../utilities/nice.html"><i>nice</i></a>, <a href=
"../utilities/ps.html"><i>ps</i></a>, and <a href="../utilities/renice.html"><i>renice</i></a>.</p>

<h5><a name="tag_04_02_12_01"></a>Unsatisfied Requirements</h5>

<p>Terminals with multiple windows may be more suitable for some multi-tasking interactive uses than the job control approach in
IEEE&nbsp;Std&nbsp;1003.1-2001. See the comments on graphical user interfaces in <a href="#tag_04_02_11">Interactive Facilities</a>
. The <a href="../utilities/nice.html"><i>nice</i></a> and <a href="../utilities/renice.html"><i>renice</i></a> utilities do not
necessarily take advantage of complex system scheduling algorithms that are supported by the realtime options within
IEEE&nbsp;Std&nbsp;1003.1-2001.</p>

<h4><a name="tag_04_02_13"></a>Complex Data Manipulation</h4>

<p>The following utilities address user requirements in this area: <a href="../utilities/asa.html"><i>asa</i></a>, <a href=
"../utilities/awk.html"><i>awk</i></a>, <a href="../utilities/bc.html"><i>bc</i></a>, <a href=
"../utilities/cmp.html"><i>cmp</i></a>, <a href="../utilities/comm.html"><i>comm</i></a>, <a href=
"../utilities/csplit.html"><i>csplit</i></a>*, <a href="../utilities/cut.html"><i>cut</i></a>, <a href=
"../utilities/dd.html"><i>dd</i></a>, <a href="../utilities/diff.html"><i>diff</i></a>, <a href=
"../utilities/ed.html"><i>ed</i></a>, <a href="../utilities/ex.html"><i>ex</i></a>*, <a href=
"../utilities/expand.html"><i>expand</i></a>*, <a href="../utilities/expr.html"><i>expr</i></a>, <a href=
"../utilities/find.html"><i>find</i></a>, <a href="../utilities/fold.html"><i>fold</i></a>, <a href=
"../utilities/grep.html"><i>grep</i></a>, <a href="../utilities/head.html"><i>head</i></a>, <a href=
"../utilities/join.html"><i>join</i></a>, <a href="../utilities/od.html"><i>od</i></a>, <a href=
"../utilities/paste.html"><i>paste</i></a>, <a href="../utilities/pr.html"><i>pr</i></a>, <a href=
"../utilities/printf.html"><i>printf</i></a>, <a href="../utilities/sed.html"><i>sed</i></a>, <a href=
"../utilities/sort.html"><i>sort</i></a>, <a href="../utilities/split.html"><i>split</i></a>*, <a href=
"../utilities/tabs.html"><i>tabs</i></a>*, <a href="../utilities/tail.html"><i>tail</i></a>, <a href=
"../utilities/tr.html"><i>tr</i></a>, <a href="../utilities/unexpand.html"><i>unexpand</i></a>*, <a href=
"../utilities/uniq.html"><i>uniq</i></a>, <a href="../utilities/uudecode.html"><i>uudecode</i></a>*, <a href=
"../utilities/uuencode.html"><i>uuencode</i></a>*, and <a href="../utilities/wc.html"><i>wc</i></a>.</p>

<h5><a name="tag_04_02_13_01"></a>Unsatisfied Requirements</h5>

<p>Sophisticated text formatting utilities, such as <i>troff</i> or <i>TeX</i>, are not included. Standards work in the area of
SGML may satisfy this.</p>

<h4><a name="tag_04_02_14"></a>File Hierarchy Manipulation</h4>

<p>The following utilities address user requirements in this area: <a href="../utilities/basename.html"><i>basename</i></a>, <a
href="../utilities/cd.html"><i>cd</i></a>, <a href="../utilities/chgrp.html"><i>chgrp</i></a>, <a href=
"../utilities/chmod.html"><i>chmod</i></a>, <a href="../utilities/chown.html"><i>chown</i></a>, <a href=
"../utilities/cksum.html"><i>cksum</i></a>, <a href="../utilities/cp.html"><i>cp</i></a>, <a href=
"../utilities/dd.html"><i>dd</i></a>, <a href="../utilities/df.html"><i>df</i></a>*, <a href=
"../utilities/diff.html"><i>diff</i></a>, <a href="../utilities/dirname.html"><i>dirname</i></a>, <a href=
"../utilities/du.html"><i>du</i></a>*, <a href="../utilities/find.html"><i>find</i></a>, <a href=
"../utilities/ls.html"><i>ls</i></a>, <a href="../utilities/ln.html"><i>ln</i></a>, <a href=
"../utilities/mkdir.html"><i>mkdir</i></a>, <a href="../utilities/mkfifo.html"><i>mkfifo</i></a>, <a href=
"../utilities/mv.html"><i>mv</i></a>, <a href="../utilities/patch.html"><i>patch</i></a>*, <a href=
"../utilities/pathchk.html"><i>pathchk</i></a>, <a href="../utilities/pax.html"><i>pax</i></a>, <a href=
"../utilities/pwd.html"><i>pwd</i></a>, <a href="../utilities/rm.html"><i>rm</i></a>, <a href=
"../utilities/rmdir.html"><i>rmdir</i></a>, <a href="../utilities/test.html"><i>test</i></a>, and <a href=
"../utilities/touch.html"><i>touch</i></a>.</p>

<h5><a name="tag_04_02_14_01"></a>Unsatisfied Requirements</h5>

<p>Some graphical user interfaces offer more intuitive file manager components that allow file manipulation through the use of
icons for novice users.</p>

<h4><a name="tag_04_02_15"></a>Locale Configuration</h4>

<p>The standard utilities are affected by the various <i>LC_</i> variables to achieve locale-dependent operation: character
classification, collation sequences, regular expressions and shell pattern matching, date and time formats, numeric formatting, and
monetary formatting. When the POSIX2_LOCALEDEF option is supported, applications can provide their own locale definition files. The
following utilities address user requirements in this area: <a href="../utilities/date.html"><i>date</i></a>, <a href=
"../utilities/ed.html"><i>ed</i></a>, <a href="../utilities/ex.html"><i>ex</i></a>*, <a href=
"../utilities/find.html"><i>find</i></a>, <a href="../utilities/grep.html"><i>grep</i></a>, <a href=
"../utilities/locale.html"><i>locale</i></a>, <a href="../utilities/localedef.html"><i>localedef</i></a>, <a href=
"../utilities/more.html"><i>more</i></a>*, <a href="../utilities/sed.html"><i>sed</i></a>, <a href=
"../utilities/sh.html"><i>sh</i></a>, <a href="../utilities/sort.html"><i>sort</i></a>, <a href=
"../utilities/tr.html"><i>tr</i></a>, <a href="../utilities/uniq.html"><i>uniq</i></a>, and <a href=
"../utilities/vi.html"><i>vi</i></a>*.</p>

<p>The <a href="../functions/iconv.html"><i>iconv</i>()</a>, <a href="../functions/iconv_close.html"><i>iconv_close</i>()</a>, and
<a href="../functions/iconv_open.html"><i>iconv_open</i>()</a> functions are available to allow an application to convert character
data between supported character sets.</p>

<p>The <a href="../utilities/gencat.html"><i>gencat</i></a> utility and the <a href=
"../functions/catopen.html"><i>catopen</i>()</a>, <a href="../functions/catclose.html"><i>catclose</i>()</a>, and <a href=
"../functions/catgets.html"><i>catgets</i>()</a> functions for message catalog manipulation are available on XSI-conformant
systems.</p>

<h5><a name="tag_04_02_15_01"></a>Unsatisfied Requirements</h5>

<p>Some aspects of multi-byte character and state-encoded character encodings have not yet been addressed. The C-language
functions, such as <a href="../functions/getopt.html"><i>getopt</i>()</a>, are generally limited to single-byte characters. The
effect of the <i>LC_MESSAGES</i> variable on message formats is only suggested at this time.</p>

<h4><a name="tag_04_02_16"></a>Inter-User Communication</h4>

<p>The following utilities address user requirements in this area: <a href="../utilities/cksum.html"><i>cksum</i></a>, <a href=
"../utilities/mailx.html"><i>mailx</i></a>*, <a href="../utilities/mesg.html"><i>mesg</i></a>*, <a href=
"../utilities/patch.html"><i>patch</i></a>*, <a href="../utilities/pax.html"><i>pax</i></a>, <a href=
"../utilities/talk.html"><i>talk</i></a>*, <a href="../utilities/uudecode.html"><i>uudecode</i></a>*, <a href=
"../utilities/uuencode.html"><i>uuencode</i></a>*, <a href="../utilities/who.html"><i>who</i></a>*, and <a href=
"../utilities/write.html"><i>write</i></a>*.</p>

<p>The historical UUCP utilities are included on XSI-conformant systems.</p>

<h5><a name="tag_04_02_16_01"></a>Unsatisfied Requirements</h5>

<p>None.</p>

<h4><a name="tag_04_02_17"></a>System Environment</h4>

<p>The following utilities address user requirements in this area: <a href="../utilities/chgrp.html"><i>chgrp</i></a>, <a href=
"../utilities/chmod.html"><i>chmod</i></a>, <a href="../utilities/chown.html"><i>chown</i></a>, <a href=
"../utilities/df.html"><i>df</i></a>*, <a href="../utilities/du.html"><i>du</i></a>*, <a href=
"../utilities/env.html"><i>env</i></a>, <a href="../utilities/getconf.html"><i>getconf</i></a>, <a href=
"../utilities/id.html"><i>id</i></a>, <a href="../utilities/logger.html"><i>logger</i></a>, <a href=
"../utilities/logname.html"><i>logname</i></a>, <a href="../utilities/mesg.html"><i>mesg</i></a>*, <a href=
"../utilities/newgrp.html"><i>newgrp</i></a>*, <a href="../utilities/ps.html"><i>ps</i></a>*, <a href=
"../utilities/stty.html"><i>stty</i></a>, <a href="../utilities/tput.html"><i>tput</i></a>*, <a href=
"../utilities/tty.html"><i>tty</i></a>, <a href="../utilities/umask.html"><i>umask</i></a>, <a href=
"../utilities/uname.html"><i>uname</i></a>, and <a href="../utilities/who.html"><i>who</i></a>*.</p>

<p>The <a href="../functions/closelog.html"><i>closelog</i>()</a>, <a href="../functions/openlog.html"><i>openlog</i>()</a>, <a
href="../functions/setlogmask.html"><i>setlogmask</i>()</a>, and <a href="../functions/syslog.html"><i>syslog</i>()</a> functions
provide System Logging facilities on XSI-conformant systems; these are analogous to the <a href=
"../utilities/logger.html"><i>logger</i></a> utility.</p>

<h5><a name="tag_04_02_17_01"></a>Unsatisfied Requirements</h5>

<p>None.</p>

<h4><a name="tag_04_02_18"></a>Printing</h4>

<p>The following utilities address user requirements in this area: <a href="../utilities/pr.html"><i>pr</i></a> and <a href=
"../utilities/lp.html"><i>lp</i></a>.</p>

<h5><a name="tag_04_02_18_01"></a>Unsatisfied Requirements</h5>

<p>There are no features to control the formatting or scheduling of the print jobs.</p>

<h4><a name="tag_04_02_19"></a>Software Development</h4>

<p>The following utilities address user requirements in this area: <a href="../utilities/ar.html"><i>ar</i></a>, <a href=
"../utilities/asa.html"><i>asa</i></a>, <a href="../utilities/awk.html"><i>awk</i></a>, <a href=
"../utilities/c99.html"><i>c99</i></a>, <a href="../utilities/ctags.html"><i>ctags</i></a>*, <a href=
"../utilities/fort77.html"><i>fort77</i></a>, <a href="../utilities/getconf.html"><i>getconf</i></a>, <a href=
"../utilities/getopts.html"><i>getopts</i></a>, <a href="../utilities/lex.html"><i>lex</i></a>, <a href=
"../utilities/localedef.html"><i>localedef</i></a>, <a href="../utilities/make.html"><i>make</i></a>, <a href=
"../utilities/nm.html"><i>nm</i></a>*, <a href="../utilities/od.html"><i>od</i></a>, <a href=
"../utilities/patch.html"><i>patch</i></a>*, <a href="../utilities/pax.html"><i>pax</i></a>, <a href=
"../utilities/strings.html"><i>strings</i></a>*, <a href="../utilities/strip.html"><i>strip</i></a>, <a href=
"../utilities/time.html"><i>time</i></a>*, and <a href="../utilities/yacc.html"><i>yacc</i></a>.</p>

<p>The <a href="../functions/system.html"><i>system</i>()</a>, <a href="../functions/popen.html"><i>popen</i>()</a>, <a href=
"../functions/pclose.html"><i>pclose</i>()</a>, <a href="../functions/regcomp.html"><i>regcomp</i>()</a>, <a href=
"../functions/regexec.html"><i>regexec</i>()</a>, <a href="../functions/regerror.html"><i>regerror</i>()</a>, <a href=
"../functions/regfree.html"><i>regfree</i>()</a>, <a href="../functions/fnmatch.html"><i>fnmatch</i>()</a>, <a href=
"../functions/getopt.html"><i>getopt</i>()</a>, <a href="../functions/glob.html"><i>glob</i>()</a>, <a href=
"../functions/globfree.html"><i>globfree</i>()</a>, <a href="../functions/wordexp.html"><i>wordexp</i>()</a>, and <a href=
"../functions/wordfree.html"><i>wordfree</i>()</a> functions allow C-language programmers to access some of the interfaces used by
the utilities, such as argument processing, regular expressions, and pattern matching.</p>

<p>The SCCS source-code control system utilities are available on systems supporting the XSI Development option.</p>

<h5><a name="tag_04_02_19_01"></a>Unsatisfied Requirements</h5>

<p>There are no language-specific development tools related to languages other than C and FORTRAN. The C tools are more complete
and varied than the FORTRAN tools. There is no data dictionary or other CASE-like development tools.</p>

<h4><a name="tag_04_02_20"></a>Future Growth</h4>

<p>It is arguable whether or not all functionality to support applications is potentially within the scope of
IEEE&nbsp;Std&nbsp;1003.1-2001. As a simple matter of practicality, it cannot be. Areas such as graphics, application
domain-specific functionality, windowing, and so on, should be in unique standards. As such, they are properly &quot;Unsatisfied
Requirements&quot; in terms of providing fully conforming applications, but ones which are outside the scope of
IEEE&nbsp;Std&nbsp;1003.1-2001.</p>

<p>However, as the standards evolve, certain functionality once considered &quot;exotic&quot; enough to be part of a separate standard
become common enough to be included in a core standard such as this. Realtime and networking, for example, have both moved from
separate standards (with much difficult cross-referencing) into IEEE&nbsp;Std&nbsp;1003.1 over time, and although no specific areas
have been identified for inclusion in future revisions, such inclusions seem likely.</p>

<h3><a name="tag_04_03"></a>Profiling Considerations</h3>

<p>This section offers guidance to writers of profiles on how the configurable options, limits, and optional behavior of
IEEE&nbsp;Std&nbsp;1003.1-2001 should be cited in profiles. Profile writers should consult the general guidance in POSIX.0 when
writing POSIX Standardized Profiles.</p>

<p>The information in this section is an inclusive list of features that should be considered by profile writers. Subsetting of
IEEE&nbsp;Std&nbsp;1003.1-2001 should follow the Base Definitions volume of IEEE&nbsp;Std&nbsp;1003.1-2001, <a href=
"../basedefs/xbd_chap02.html#tag_02_01_05_01">Section 2.1.5.1, Subprofiling Considerations</a>. A set of profiling options is
described in <a href="subprofiles.html#tag_05"><i>Subprofiling Considerations (Informative)</i></a> .</p>

<h4><a name="tag_04_03_01"></a>Configuration Options</h4>

<p>There are two set of options suggested by IEEE&nbsp;Std&nbsp;1003.1-2001: those for POSIX-conforming systems and those for
X/Open System Interface (XSI) conformance. The requirements for XSI conformance are documented in the Base Definitions volume of
IEEE&nbsp;Std&nbsp;1003.1-2001 and not discussed further here, as they superset the POSIX conformance requirements.</p>

<h4><a name="tag_04_03_02"></a>Configuration Options (Shell and Utilities)</h4>

<p>There are three broad optional configurations for the Shell and Utilities volume of IEEE&nbsp;Std&nbsp;1003.1-2001: basic
execution system, development system, and user portability interactive system. The options to support these, and other minor
configuration options, are listed in the Base Definitions volume of IEEE&nbsp;Std&nbsp;1003.1-2001, <a href=
"../basedefs/xbd_chap02.html#tag_02">Chapter 2, Conformance</a>. Profile writers should consult the following list and the comments
concerning user requirements addressed by various components in <a href="#tag_04_02">Portability Capabilities</a> .</p>

<dl compact>
<dt>POSIX2_UPE</dt>

<dd>
The system supports the User Portability Utilities option. 

<p>This option is a requirement for a user portability interactive system. It is required frequently except for those systems, such
as embedded realtime or dedicated application systems, that support little or no interactive time-sharing work by users or
operators. XSI-conformant systems support this option.</p>
</dd>

<dt>POSIX2_SW_DEV</dt>

<dd>
The system supports the Software Development Utilities option. 

<p>This option is required by many systems, even those in which actual software development does not occur. The <a href=
"../utilities/make.html"><i>make</i></a> utility, in particular, is required by many application software packages as they are
installed onto the system. If POSIX2_C_DEV is supported, POSIX2_SW_DEV is almost a mandatory requirement because of <a href=
"../utilities/ar.html"><i>ar</i></a> and <a href="../utilities/make.html"><i>make</i></a>.</p>
</dd>

<dt>POSIX2_C_BIND</dt>

<dd>
The system supports the C-Language Bindings option. 

<p>This option is required on some implementations developing complex C applications or on any system installing C applications in
source form that require the functions in this option. The <a href="../functions/system.html"><i>system</i>()</a> and <a href=
"../functions/popen.html"><i>popen</i>()</a> functions, in particular, are widely used by applications; the others are rather more
specialized.</p>
</dd>

<dt>POSIX2_C_DEV</dt>

<dd>
The system supports the C-Language Development Utilities option. 

<p>This option is required by many systems, even those in which actual C-language software development does not occur. The <a href=
"../utilities/c99.html"><i>c99</i></a> utility, in particular, is required by many application software packages as they are
installed onto the system. The <a href="../utilities/lex.html"><i>lex</i></a> and <a href="../utilities/yacc.html"><i>yacc</i></a>
utilities are used less frequently.</p>
</dd>

<dt>POSIX2_FORT_DEV</dt>