xenial (1) iconv.1posix.gz

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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.

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.1‐2008, 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.1‐2008, 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.1‐2008, 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 8859‐1:1998 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.1‐2008, Section 6.4, Character Set Description File, Chapter 8,
       Environment Variables, Section 12.2, Utility Syntax Guidelines

       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 .

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