iconv(1posix)
NAME
iconv --- codeset conversion
SYNOPSIS
iconv [cs] f frommap t tomap [file...] iconv f fromcode [cs] [t tocode] [file...] iconv t tocode [cs] [f fromcode] [file...] iconv l
DESCRIPTION
The iconv utility shall convert the encoding of characters in file from one codeset to another and write the results to standard output. When the options indicate that charmap files are used to specify the codesets (see OPTIONS), the codeset conversion shall be accomplished by performing a logical join on the symbolic character names in the two charmaps. The implementation need not support the use of charmap files for codeset conversion unless the POSIX2_LOCALEDEF symbol is defined on the system.
OPTIONS
The iconv utility shall conform to the Base Definitions volume of
POSIX.12008, Section 12.2, Utility Syntax Guidelines.
The following options shall be supported:
c Omit any characters that are invalid in the codeset of the
input file from the output. When c is not used, the results
of encountering invalid characters in the input stream
(either those that are not characters in the codeset of the
input file or that have no corresponding character in the
codeset of the output file) shall be specified in the system
documentation. The presence or absence of c shall not affect
the exit status of iconv.
f fromcodeset
Identify the codeset of the input file. The implementation
shall recognize the following two forms of the fromcodeset
option-argument:
fromcode The fromcode option-argument must not contain a
<slash> character. It shall be interpreted as the
name of one of the codeset descriptions provided by
the implementation in an unspecified format. Valid
values of fromcode are implementation-defined.
frommap The frommap option-argument must contain a <slash>
character. It shall be interpreted as the pathname
of a charmap file as defined in the Base
Definitions volume of POSIX.12008, Section 6.4,
Character Set Description File. If the pathname
does not represent a valid, readable charmap file,
the results are undefined.
If this option is omitted, the codeset of the current locale
shall be used.
l Write all supported fromcode and tocode values to standard
output in an unspecified format.
s Suppress any messages written to standard error concerning
invalid characters. When s is not used, the results of
encountering invalid characters in the input stream (either
those that are not valid characters in the codeset of the
input file or that have no corresponding character in the
codeset of the output file) shall be specified in the system
documentation. The presence or absence of s shall not affect
the exit status of iconv.
t tocodeset
Identify the codeset to be used for the output file. The
implementation shall recognize the following two forms of the
tocodeset option-argument:
tocode The semantics shall be equivalent to the f
fromcode option.
tomap The semantics shall be equivalent to the f frommap
option.
If this option is omitted, the codeset of the current locale
shall be used.
If either f or t represents a charmap file, but the other does not
(or is omitted), or both f and t are omitted, the results are
undefined.
OPERANDS
The following operand shall be supported:
file A pathname of an input file. If no file operands are
specified, or if a file operand is '', the standard input
shall be used.
STDIN
The standard input shall be used only if no file operands are specified, or if a file operand is ''.
INPUT FILES
The input file shall be a text file.
ENVIRONMENT VARIABLES
The following environment variables shall affect the execution of
iconv:
LANG Provide a default value for the internationalization
variables that are unset or null. (See the Base Definitions
volume of POSIX.12008, Section 8.2, Internationalization
Variables for the precedence of internationalization
variables used to determine the values of locale categories.)
LC_ALL If set to a non-empty string value, override the values of
all the other internationalization variables.
LC_CTYPE 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). During
translation of the file, this variable is superseded by the
use of the fromcode option-argument.
LC_MESSAGES
Determine the locale that should be used to affect the format
and contents of diagnostic messages written to standard
error.
NLSPATH Determine the location of message catalogs for the processing
of LC_MESSAGES.
ASYNCHRONOUS EVENTS
Default.
STDOUT
When the l option is used, the standard output shall contain all supported fromcode and tocode values, written in an unspecified format. When the l option is not used, the standard output shall contain the sequence of characters read from the input files, translated to the specified codeset. Nothing else shall be written to the standard output.
STDERR
The standard error shall be used only for diagnostic messages.
OUTPUT FILES
None.
EXTENDED DESCRIPTION
None.
EXIT STATUS
The following exit values shall be returned:
0 Successful completion.
>0 An error occurred.
CONSEQUENCES OF ERRORS
Default. The following sections are informative.
APPLICATION USAGE
The user must ensure that both charmap files use the same symbolic names for characters the two codesets have in common.
EXAMPLES
The following example converts the contents of file mail.x400 from the
ISO/IEC 6937:2001 standard codeset to the ISO/IEC 88591:1998 standard
codeset, and stores the results in file mail.local:
iconv f IS6937 t IS8859 mail.x400 > mail.local
RATIONALE
The iconv utility can be used portably only when the user provides two charmap files as option-arguments. This is because a single charmap provided by the user cannot reliably be joined with the names in a system-provided character set description. The valid values for fromcode and tocode are implementation-defined and do not have to have any relation to the charmap mechanisms. As an aid to interactive users, the l option was adopted from the Plan 9 operating system. It writes information concerning these implementation-defined values. The format is unspecified because there are many possible useful formats that could be chosen, such as a matrix of valid combinations of fromcode and tocode. The l option is not intended for shell script usage; conforming applications will have to use charmaps. The iconv utility may support the conversion between ASCII and EBCDIC- based encodings, but is not required to do so. In an XSI-compliant implementation, the dd utility is the only method guaranteed to support conversion between these two character sets.
FUTURE DIRECTIONS
None.
SEE ALSO
dd, gencat The Base Definitions volume of POSIX.12008, Section 6.4, Character Set Description File, Chapter 8, Environment Variables, Section 12.2, Utility Syntax Guidelines
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, Copyright (C) 2013 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/online.html . Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .
Opportunity
Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.
Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.
Free Software
Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.
Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.
Free Books
The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.
Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.
Education
Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.
Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.
