Installing stringi

In most cases, installing stringi is as simple as calling:


However, due to the overwhelming complexity of the ICU4C library, upon which stringi is based, and the colourful diversity of operating systems, their flavours, and particular setups, some users may still experience a few issues that hopefully can be resolved with the help of this short manual.

Also, some build tweaks are possible.


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

If we install 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 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 environment variable STRINGI_DISABLE_PKG_CONFIG is set to non-zero or install.packages("stringi", configure.args="--disable-pkg-config") is executed,

then ICU will be built together with stringi. A custom subset of ICU4C 69.1 is shipped with the package. We also include ICU4C 55.1 which can be used as a fallback version (e.g., on older Solaris boxes).

To get the most out of stringi, you are strongly encouraged to rely on our ICU4C package bundle. This ensures maximum portability across all platforms (Windows and macOS users by default fetch the pre-compiled binaries from CRAN built precisely this way).

ICU Data Library and No Internet Access

Note that if you choose to use our ICU4C bundle, then – by default – the ICU data library will be downloaded from one of our mirror servers. However, if you have already 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 no internet access on the machines you try to install stringi on, try fetching the latest development version of the package, as it is 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 x.y.z, a file named stringi_x.y.z.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_x.y.z.tar.gz

Alternatively, call from within an R session:

install.packages("stringi_x.y.z.tar.gz", repos=NULL)

C++11 Issues

A decent C++11 compiler is required to build ICU4C 69.1 from sources.

Note that Pre-4.9.0 GCC has a bug where ::max_align_t has been defined, but not std::max_align_t. If our built-in workaround does not work, you may try calling:

install.packages("stringi", configure.args="--with-extra-cxxflags='-std=c++11'")

Overall, your build chain may be misconfigured, check out, amongst others, <R_inst_dir>/etc/Makeconf (e.g., are you using -std=gnu++11 instead of -std=c++11?). Refer to for more details.

There is an option of using the fallback version of ICU4C 55.1. However, it requires the support of the long long type in a few functions, (this is not part of the C++98 standard; works on Solaris, though). Try:

install.packages("stringi", configure.args="--disable-cxx11")

Customising the Build Process

Additional features and options of the ./configure script:

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

  • --disable-icu-bundle: Enforce system ICU.

  • --disable-pkg-config: Disable pkg-config; 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 with an already downloaded ICU data archive (icudt*.zip); either an absolute path or a path relative to <package source dir>/src; defaults to icuXX/data.

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

  • R_HOME: Override the R directory, e.g., /usr/lib64/R. Note that $R_HOME/bin/R point 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 the existing libicu installation.

  • STRINGI_DISABLE_CXX11: Disable C++11; see also --disable-cxx11.

  • STRINGI_DISABLE_PKG_CONFIG: Compile ICU from sources; see also --disable-pkg-config.

  • STRINGI_DISABLE_ICU_BUNDLE: Enforce 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 face no problems installing the package, especially if you use our ICU4C bundle and have a working internet access.

If you do not manage to set up a successful stringi build, do not hesitate to file a bug report. However, please check the list of archived (closed) issues first – it is very likely that a solution to your problem has already been posted.

To help diagnose your error further, please run (from the terminal):

cd /tmp
cd stringi-master

And submit the output from ./configure as well as the contents of config.log.