Installing stringi


In 99.9% of cases, stringi can be successfully installed by simply calling:


However, due to the overwhelming complexity of the ICU4C library, on which stringi is based, and the colourful variety of operating systems, their flavors, and particular setups, some users may still be subject to a few issues.

Also, some additional build tweaks are possible to those who want a more customised installation.


The stringi package depends on the ICU4C >= 55 library.

If you build the package from sources and either:

  • this requirement is not met (check out, the libicu-devel rpm on Fedora/CentOS/OpenSUSE, libicu-dev on Ubuntu/Debian, etc.),

  • pkg-config is fails to find appropriate build settings for ICU-based projects, or

  • R CMD INSTALL is called with the --configure-args='--disable-pkg-config' argument or install.packages("stringi", configure.args="--disable-pkg-config") is executed,

then the library will be built together with stringi (a custom subset of ICU4C 55.1 and 61.1 is shipped with the package).

To get the most out of stringi, end users are encouraged to rely on our ICU4C package bundle. This guarantees maximum portability.

If you decide to use our ICU4C bundle, then – by default – the ICU data library will be downloaded from one of our mirror servers. However, if you already have downloaded a version of icudt*.zip suitable for your platform (big/little endian), you may wish to install the package by calling:

install.packages("stringi", configure.vars="ICUDT_DIR=<icudt_dir>")

Moreover, if you have absolutely no internet access on the machines you try to install stringi on, try fetching the latest development version of the package. It is already shipped with the ICU data archives. You can build a distributable source package that includes all the required ICU data files (for off-line use) by omitting some relevant lines in the .Rbuildignore file. The following command sequence should do the trick:

wget -O
sed -i '/\/icu..\/data/d' stringi-master/.Rbuildignore
R CMD build stringi-master

Assuming the most recent development version of the package is numbered 1.5.3, a file named stringi_1.5.3.tar.gz is created in the current working directory. The package can now be installed (the source bundle may be propagated via scp etc.) by executing:

R CMD INSTALL stringi_1.5.3.tar.gz

or by calling install.packages("stringi_1.3.1.tar.gz", repos=NULL), from within an R session.

C++11 Support

For R >= 3.1.0, we suggest (by default) C++11 support to build the package from sources. This is because older releases of ICU4C use the long long type in a few functions, and this is not part of the C++98 standard. Moreover, it has become required by newer versions of ICU4C.

However, if your compiler does not support C++11 or it has not been properly configured (check out <R_inst_dir>/etc/Makeconf) but you are sure it tolerates the long long type (which is very common – this is checked by the configure script anyway), you may disable the use of C++11 by passing the --disable-cxx11 argument to the configure script.

Customising the Build Process

Additional features and options of the ./configure script:

  • --disable-cxx11: Disable use of C++11; if you build ICU4C from sources, make sure your C++ compiler supports the long long type.

  • --disable-icu-bundle: Force the use of the system ICU.

  • --disable-pkg-config: Disable pkg-config usage for finding ICU4C-devel; in such a case ICU4C will be compiled from sources.

  • --with-extra-cflags=FLAGS: Additional C compiler flags.

  • --with-extra-cppflags=FLAGS: Additional C/C++ preprocessor flags.

  • --with-extra-cxxflags=FLAGS: Additional C++ compiler flags.

  • --with-extra-ldflags=FLAGS: Additional linker flags.

  • --with-extra-libs=FLAGS: Additional libraries to link against.

Some influential environment variables:

  • ICUDT_DIR: Optional directory from which an already downloaded ICU data archive (icudt*.zip) may be copied; either an absolute path or a path relative to <package source dir>/src; defaults to icu55/data.

  • PKG_CONFIG_PATH: An optional list of directories to search for pkg-configs .pc files.

  • R_HOME: Override default directory with R installation, e.g., /usr/lib64/R. Note that $R_HOME/bin/R should refer to the R executable.

  • CAT: The cat command used to generate the list of source files to compile.

  • PKG_CONFIG:The pkg-config command used to fetch the necessary compiler flags to link to and existing libicu installation.

  • STRINGI_DISABLE_CXX11: Disable the use of C++11, see also --disable-cxx11.

  • STRINGI_DISABLE_PKG_CONFIG: Force the use of the ICU bundle, see also --disable-pkg-config.

  • STRINGI_DISABLE_ICU_BUNDLE: Force the use of the system ICU, see also --disable-icu-bundle.

  • STRINGI_CFLAGS: see --with-extra-cflags.

  • STRINGI_CPPFLAGS: see --with-extra-cppflags.

  • STRINGI_CXXFLAGS: see --with-extra-cxxflags.

  • STRINGI_LDFLAGS: see --with-extra-ldflags.

  • STRINGI_LIBS: see --with-extra-libs.


We expect that with a correctly configured C++11 compiler and properly installed system ICU4C distribution, you should experience no problems with installing the package. Also, if you use our ICU4C bundle and you have a working internet access, all should lead to a happy ending.

If you do not manage to set up a successful stringi build, do not hesitate to file a bug report. However, please check the archived (closed) issues for similar problems experienced by other users — it is very likely that they have already been resolved successfully.