iconv1

Usage

Overview

The iconv program reads in text in one encoding and outputs the text in another encoding. If no input files are given, or if it is given as a dash (-), iconv reads from standard input. If no output file is given, iconv writes to standard output.

If no from-encoding is given, the default is derived from the current locale's character encoding. If no to-encoding is given, the default is derived from the current locale's character encoding.

Options

--from-code=from-encoding
-f from-encoding

Use from-encoding for input characters.

--to-code=to-encoding
-t to-encoding

Use to-encoding for output characters.

If the string //IGNORE is appended to to-encoding, characters that cannot be converted are discarded and an error is printed after conversion. (Characters that cannot be decoded are treated as an error with or without this flag.)

If the string //TRANSLIT is appended to to-encoding, characters being converted are transliterated when needed and possible. This means that when a character cannot be represented in the target character set, it can be approximated through one or several similar looking characters. Characters that are outside of the target character set and cannot be transliterated are replaced with a question mark (?) in the output.

--list
-l

List all known character set encodings.

-c

Discard characters that cannot be converted instead of terminating when encountering such characters. POSIX requires that this option does not change the exit status of the program.

--output=outputfile
-o outputfile

Use outputfile for output.

--silent
-s

This option is ignored; it is provided only for compatibility.

--verbose

Print progress information on standard error when processing multiple files.

--help
-?

Print a usage summary and exit.

--usage

Print a short usage summary and exit.

--version
-V

Print the version number, license, and disclaimer of warranty for iconv.

Exit status

Zero on success, nonzero on errors.

Environment

Internally, the iconv program uses the iconv(3) function which in turn uses gconv modules (dynamically loaded shared libraries) to convert to and from a character set. Before calling iconv(3), the iconv program must first allocate a conversion descriptor using iconv_open(3). The operation of the latter function is influenced by the setting of the GCONV_PATH environment variable:

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If GCONV_PATH is not set, iconv_open(3) loads the system gconv module configuration cache file created by iconvconfig(8) and then, based on the configuration, loads the gconv modules needed to perform the conversion. If the system gconv module configuration cache file is not available then the system gconv module configuration file is used.

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If GCONV_PATH is defined (as a colon-separated list of pathnames), the system gconv module configuration cache is not used. Instead, iconv_open(3) first tries to load the configuration files by searching the directories in GCONV_PATH in order, followed by the system default gconv module configuration file. If a directory does not contain a gconv module configuration file, any gconv modules that it may contain are ignored. If a directory contains a gconv module configuration file and it is determined that a module needed for this conversion is available in the directory, then the needed module is loaded from that directory, the order being such that the first suitable module found in GCONV_PATH is used. This allows users to use custom modules and even replace system-provided modules by providing such modules in GCONV_PATH directories.

Files

/usr/lib/gconv

Usual default gconv module path.

/usr/lib/gconv/gconv-modules

Usual system default gconv module configuration file.

/usr/lib/gconv/gconv-modules.cache

Usual system gconv module configuration cache.

Depending on the architecture, the above files may instead be located at directories with the path prefix /usr/lib64.

Examples

Convert text from the ISO/IEC 8859-15 character encoding to UTF-8:

$ iconv -f ISO-8859-15 -t UTF-8 < input.txt > output.txt;

The next example converts from UTF-8 to ASCII, transliterating when possible:

$ echo abc ß α € àḃç | iconv -f UTF-8 -t ASCII//TRANSLIT;
abc ss ? EUR abc