Excuse me for reporting this bug here. It seems to be the upstream's bug. But I've failed to find proper upstream bugzilla. On OSF1 "apropos ++" works correctly. On my Gentoo GNU/Linux system using man-db I get the following error: $ apropos ++ apropos: fatal: regex `++': Invalid preceding regular expression $ apropos \+ apropos: fatal: regex `+': Invalid preceding regular expression $ apropos "+" apropos: fatal: regex `+': Invalid preceding regular expression $ apropos '+' apropos: fatal: regex `+': Invalid preceding regular expression related applications: $ eix -Ie man-db Available versions: (~)2.6.0.2 (~)2.6.1 (~)2.6.2 {{berkdb +gdbm nls static-libs zlib}} Installed versions: 2.6.2(10:17:27 AM 08/07/2012)(berkdb gdbm nls zlib -static-libs) Homepage: http://www.nongnu.org/man-db/ Description: a man replacement that utilizes berkdb instead of flat files $ eix -Ie gettext [I] sys-devel/gettext Available versions: 0.18.1.1-r1 ~0.18.1.1-r2 ~0.18.1.1-r3 {{acl -cvs +cxx doc elibc_FreeBSD elibc_glibc emacs git java nls openmp static-libs}} Installed versions: 0.18.1.1-r1(09:26:47 AM 06/08/2012)(acl cxx elibc_glibc nls openmp -doc -emacs -git) Homepage: http://www.gnu.org/software/gettext/ Description: GNU locale utilities $ emerge --info Portage 2.1.11.9 (default/linux/amd64/10.0, gcc-4.5.4, glibc-2.15-r2, 3.4.9-gentoo x86_64) ================================================================= System uname: Linux-3.4.9-gentoo-x86_64-AMD_Athlon-tm-_II_X2_250_Processor-with-gentoo-2.1 Timestamp of tree: Mon, 10 Sep 2012 00:45:01 +0000 app-shells/bash: 4.2_p37 dev-java/java-config: 2.1.11-r3 dev-lang/python: 2.7.3-r2, 3.2.3 dev-util/cmake: 2.8.7-r5 dev-util/pkgconfig: 0.27.1 sys-apps/baselayout: 2.1-r1 sys-apps/openrc: 0.9.8.4 sys-apps/sandbox: 2.5 sys-devel/autoconf: 2.13, 2.68 sys-devel/automake: 1.9.6-r3, 1.11.6 sys-devel/binutils: 2.22-r1 sys-devel/gcc: 4.5.4 sys-devel/gcc-config: 1.7.3 sys-devel/libtool: 2.4-r1 sys-devel/make: 3.82-r3 sys-kernel/linux-headers: 3.4-r2 (virtual/os-headers) sys-libs/glibc: 2.15-r2 Repositories: gentoo location: /usr/portage sync: rsync://rsync.mydomain.ru/gentoo-portage/ priority: -1000 x-portage location: /usr/local/portage masters: gentoo priority: 0 ABI="amd64" ACCEPT_KEYWORDS="amd64" ACCEPT_LICENSE="* -@EULA" ACCEPT_PROPERTIES="*" ALSA_CARDS="ali5451 als4000 atiixp atiixp-modem bt87x ca0106 cmipci emu10k1x ens1370 ens1371 es1938 es1968 fm801 hda-intel intel8x0 intel8x0m maestro3 trident usb-audio via82xx via82xx-modem ymfpci" ALSA_PCM_PLUGINS="adpcm alaw asym copy dmix dshare dsnoop empty extplug file hooks iec958 ioplug ladspa lfloat linear meter mmap_emul mulaw multi null plug rate route share shm softvol" APACHE2_MODULES="actions alias auth_basic authn_alias authn_anon authn_dbm authn_default authn_file authz_dbm authz_default authz_groupfile authz_host authz_owner authz_user autoindex cache cgi cgid dav dav_fs dav_lock deflate dir disk_cache env expires ext_filter file_cache filter headers include info log_config logio mem_cache mime mime_magic negotiation rewrite setenvif speling status unique_id userdir usertrack vhost_alias" ARCH="amd64" AUTOCLEAN="yes" BOOTSTRAP_USE="cxx unicode multilib" CALLIGRA_FEATURES="kexi words flow plan sheets stage tables krita karbon braindump" CAMERAS="ptp2" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-march=native -O2 -pipe" CFLAGS_amd64="-m64" CFLAGS_x32="-mx32" CFLAGS_x86="-m32" CHOST="x86_64-pc-linux-gnu" CHOST_amd64="x86_64-pc-linux-gnu" CHOST_x32="x86_64-pc-linux-gnux32" CHOST_x86="i686-pc-linux-gnu" CLEAN_DELAY="5" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" COLLISION_IGNORE="/lib/modules/* *.py[co]" COLORTERM="Terminal" CONFIG_PROTECT="/etc /usr/share/gnupg/qualified.txt /var/bind" CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/env.d /etc/env.d/java/ /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/php/apache2-php5.4/ext-active/ /etc/php/cgi-php5.4/ext-active/ /etc/php/cli-php5.4/ext-active/ /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo /etc/texmf/language.dat.d /etc/texmf/language.def.d /etc/texmf/updmap.d /etc/texmf/web2c" CXXFLAGS="-march=native -O2 -pipe" C_INCLUDE_PATH="/usr/lib64/oracle/10.2.0.3/client/include" DBUS_SESSION_BUS_ADDRESS="unix:abstract=/tmp/dbus-3Hj7RdHhyL,guid=bf85459a76daef6ebce7a50650501500" DEFAULT_ABI="amd64" DESKTOP_SESSION="xfce" DISPLAY=":0.0" DISTDIR="/usr/portage/distfiles" EDITOR="/usr/bin/vi" ELIBC="glibc" EMERGE_DEFAULT_OPTS="--ask --verbose --autounmask=n" EMERGE_WARNING_DELAY="10" EPREFIX="" EROOT="/" FCFLAGS="-O2 -pipe" FEATURES="assume-digests binpkg-logs buildsyspkg config-protect-if-modified distlocks ebuild-locks fixlafiles news parallel-fetch parse-eapi-ebuild-head protect-owned sandbox sfperms strict unknown-features-warn unmerge-logs unmerge-orphans userfetch" FETCHCOMMAND="wget -t 3 -T 60 --passive-ftp -O "${DISTDIR}/${FILE}" "${URI}"" FETCHCOMMAND_RSYNC="rsync -avP "${URI}" "${DISTDIR}/${FILE}"" FETCHCOMMAND_SFTP="bash -c "x=\${2#sftp://} ; host=\${x%%/*} ; port=\${host##*:} ; host=\${host%:*} ; [[ \${host} = \${port} ]] && port=22 ; exec sftp -P \${port} \"\${host}:/\${x#*/}\" \"\$1\"" sftp "${DISTDIR}/${FILE}" "${URI}"" FETCHCOMMAND_SSH="bash -c "x=\${2#ssh://} ; host=\${x%%/*} ; port=\${host##*:} ; host=\${host%:*} ; [[ \${host} = \${port} ]] && port=22 ; exec rsync --rsh=\"ssh -p\${port}\" -avP \"\${host}:/\${x#*/}\" \"\$1\"" rsync "${DISTDIR}/${FILE}" "${URI}"" FFLAGS="-O2 -pipe" GCC_SPECS="" GDK_USE_XFT="1" GENTOO_MIRRORS="http://mirror.yandex.ru/gentoo-distfiles/ ftp://mirror.yandex.ru/gentoo-distfiles/ http://ftp.chg.ru/pub/Linux/distributions/gentoo/ ftp://ftp.chg.ru/pub/Linux/distributions/gentoo/ http://ftp.corbina.net/pub/Linux/gentoo/ ftp://ftp.corbina.net/pub/Linux/gentoo/" GLADE_CATALOG_PATH=":" GLADE_MODULE_PATH=":" GLADE_PIXMAP_PATH=":" GPG_AGENT_INFO="/tmp/gpg-UNmTIu/S.gpg-agent:2301:1" GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt gpsclock itrax mtk3301 nmea ntrip navcom oceanserver oldstyle oncore rtcm104v2 rtcm104v3 sirf superstar2 timing tsip tripmate tnt ubx" GRUB_PLATFORMS="" GSETTINGS_BACKEND="gconf" HOME="/home/ftn" INFOPATH="/usr/share/info:/usr/share/gcc-data/x86_64-pc-linux-gnu/4.5.4/info:/usr/share/binutils-data/x86_64-pc-linux-gnu/2.22/info" INPUT_DEVICES="evdev" JAVAC="/etc/java-config-2/current-system-vm/bin/javac" JAVA_HOME="/etc/java-config-2/current-system-vm" JDK_HOME="/etc/java-config-2/current-system-vm" KERNEL="linux" LANG="en_US" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LC_ALL="" LC_NUMERIC="C" LDFLAGS="-Wl,-O1 -Wl,--as-needed" LDFLAGS_amd64="-m elf_x86_64" LDFLAGS_x32="-m elf32_x86_64" LDFLAGS_x86="-m elf_i386" LESS="-R -M --shift 5" LESSOPEN="|lesspipe %s" LIBDIR_amd64="lib64" LIBDIR_amd64_fbsd="lib64" LIBDIR_n32="lib32" LIBDIR_n64="lib64" LIBDIR_o32="lib" LIBDIR_ppc="lib32" LIBDIR_ppc64="lib64" LIBDIR_s390="lib32" LIBDIR_s390x="lib64" LIBDIR_sparc32="lib32" LIBDIR_sparc64="lib64" LIBDIR_x32="libx32" LIBDIR_x86="lib32" LIBDIR_x86_fbsd="lib32" LIBREOFFICE_EXTENSIONS="presenter-console presenter-minimizer" LINGUAS="ru" LOGNAME="user" LS_COLORS="rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=01;05;37;41:mi=01;05;37;41:su=37;41:sg=30;43:ca=30;41:tw=30;42:ow=34;42:st=37;44:ex=01;32:*.tar=01;31:*.tgz=01;31:*.arj=01;31:*.taz=01;31:*.lzh=01;31:*.lzma=01;31:*.tlz=01;31:*.txz=01;31:*.zip=01;31:*.z=01;31:*.Z=01;31:*.dz=01;31:*.gz=01;31:*.lz=01;31:*.xz=01;31:*.bz2=01;31:*.bz=01;31:*.tbz=01;31:*.tbz2=01;31:*.tz=01;31:*.deb=01;31:*.rpm=01;31:*.jar=01;31:*.war=01;31:*.ear=01;31:*.sar=01;31:*.rar=01;31:*.ace=01;31:*.zoo=01;31:*.cpio=01;31:*.7z=01;31:*.rz=01;31:*.jpg=01;35:*.jpeg=01;35:*.gif=01;35:*.bmp=01;35:*.pbm=01;35:*.pgm=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:*.tif=01;35:*.tiff=01;35:*.png=01;35:*.svg=01;35:*.svgz=01;35:*.mng=01;35:*.pcx=01;35:*.mov=01;35:*.mpg=01;35:*.mpeg=01;35:*.m2v=01;35:*.mkv=01;35:*.webm=01;35:*.ogm=01;35:*.mp4=01;35:*.m4v=01;35:*.mp4v=01;35:*.vob=01;35:*.qt=01;35:*.nuv=01;35:*.wmv=01;35:*.asf=01;35:*.rm=01;35:*.rmvb=01;35:*.flc=01;35:*.avi=01;35:*.fli=01;35:*.flv=01;35:*.gl=01;35:*.dl=01;35:*.xcf=01;35:*.xwd=01;35:*.yuv=01;35:*.cgm=01;35:*.emf=01;35:*.axv=01;35:*.anx=01;35:*.ogv=01;35:*.ogx=01;35:*.pdf=00;32:*.ps=00;32:*.txt=00;32:*.patch=00;32:*.diff=00;32:*.log=00;32:*.tex=00;32:*.doc=00;32:*.aac=00;36:*.au=00;36:*.flac=00;36:*.mid=00;36:*.midi=00;36:*.mka=00;36:*.mp3=00;36:*.mpc=00;36:*.ogg=00;36:*.ra=00;36:*.wav=00;36:*.axa=00;36:*.oga=00;36:*.spx=00;36:*.xspf=00;36:" MAIL="/var/mail/user" MAKEOPTS="-j2" MANPATH="/etc/java-config-2/current-system-vm/man:/usr/local/share/man:/usr/share/man:/usr/share/gcc-data/x86_64-pc-linux-gnu/4.5.4/man:/usr/share/binutils-data/x86_64-pc-linux-gnu/2.22/man:/etc/java-config/system-vm/man/:/usr/lib64/php5.4/man/" MULTILIB_ABIS="amd64 x86" MULTILIB_STRICT_DENY="64-bit.*shared object" MULTILIB_STRICT_DIRS="/lib32 /lib /usr/lib32 /usr/lib /usr/kde/*/lib32 /usr/kde/*/lib /usr/qt/*/lib32 /usr/qt/*/lib /usr/X11R6/lib32 /usr/X11R6/lib" MULTILIB_STRICT_EXEMPT="(perl5|gcc|gcc-lib|binutils|eclipse-3|debug|portage|udev)" NETBEANS="apisupport cnd groovy gsf harness ide identity j2ee java mobility nb php profiler soa visualweb webcommon websvccommon xml" NLS_LANG="russian_cis.cl8iso8859p5" OPENGL_PROFILE="xorg-x11" ORACLE_HOME="/usr/lib64/oracle/10.2.0.3/client" PAGER="/usr/bin/less" PATH="/usr/local/bin:/usr/bin:/bin:/opt/bin:/usr/x86_64-pc-linux-gnu/gcc-bin/4.5.4:~/bin" PHP_TARGETS="php5-3" PKGDIR="/usr/portage/packages" PORTAGE_ARCHLIST="ppc sparc64-freebsd ppc-openbsd x86-openbsd ppc64 x86-winnt x86-fbsd ppc-aix alpha arm x86-freebsd s390 amd64 arm-linux x86-macos x64-openbsd ia64-hpux hppa x86-netbsd ppc64-linux x86-cygwin amd64-linux ia64-linux x86 sparc-solaris x64-freebsd sparc64-solaris x86-linux x64-macos sparc m68k-mint ia64 mips ppc-macos x86-interix hppa-hpux amd64-fbsd x64-solaris m68k sh x86-solaris sparc-fbsd" PORTAGE_BINHOST_CHUNKSIZE="3000" PORTAGE_BIN_PATH="/usr/lib64/portage/bin" PORTAGE_COMPRESS_EXCLUDE_SUFFIXES="css gif htm[l]? jp[e]?g js pdf png" PORTAGE_CONFIGROOT="/" PORTAGE_DEBUG="0" PORTAGE_DEPCACHEDIR="/var/cache/edb/dep" PORTAGE_ELOG_CLASSES="log warn error" PORTAGE_ELOG_MAILFROM="portage@localhost" PORTAGE_ELOG_MAILSUBJECT="[portage] ebuild log for ${PACKAGE} on ${HOST}" PORTAGE_ELOG_MAILURI="root" PORTAGE_ELOG_SYSTEM="save_summary echo" PORTAGE_FETCH_CHECKSUM_TRY_MIRRORS="5" PORTAGE_FETCH_RESUME_MIN_SIZE="350K" PORTAGE_GID="250" PORTAGE_GPG_SIGNING_COMMAND="gpg --sign --digest-algo SHA256 --clearsign --yes --default-key "${PORTAGE_GPG_KEY}" --homedir "${PORTAGE_GPG_DIR}" "${FILE}"" PORTAGE_INST_GID="0" PORTAGE_INST_UID="0" PORTAGE_OVERRIDE_EPREFIX="" PORTAGE_PYM_PATH="/usr/lib64/portage/pym" PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --compress --force --whole-file --delete --stats --human-readable --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages" PORTAGE_RSYNC_RETRIES="-1" PORTAGE_SYNC_STALE="30" PORTAGE_TMPDIR="/var/tmp" PORTAGE_VERBOSE="1" PORTAGE_WORKDIR_MODE="0700" PORTDIR="/usr/portage" PORTDIR_OVERLAY="/usr/local/portage" PORT_LOGDIR_CLEAN="find "${PORT_LOGDIR}" -type f ! -name "summary.log*" -mtime +7 -delete" PRELINK_PATH_MASK="/usr/lib64/libfreebl3.so:/usr/lib64/libnssdbm3.so:/usr/lib64/libsoftokn3.so" PROFILE_ONLY_VARIABLES="ARCH ELIBC KERNEL USERLAND" PWD="/home/ftn" PYTHONDONTWRITEBYTECODE="1" PYTHON_TARGETS="python3_2 python2_7" QT_GRAPHICSSYSTEM="raster" RESUMECOMMAND="wget -c -t 3 -T 60 --passive-ftp -O "${DISTDIR}/${FILE}" "${URI}"" RESUMECOMMAND_RSYNC="rsync -avP "${URI}" "${DISTDIR}/${FILE}"" RESUMECOMMAND_SSH="bash -c "x=\${2#ssh://} ; host=\${x%%/*} ; port=\${host##*:} ; host=\${host%:*} ; [[ \${host} = \${port} ]] && port=22 ; exec rsync --rsh=\"ssh -p\${port}\" -avP \"\${host}:/\${x#*/}\" \"\$1\"" rsync "${DISTDIR}/${FILE}" "${URI}"" ROOT="/" ROOTPATH="/opt/bin:/usr/x86_64-pc-linux-gnu/gcc-bin/4.5.4" RPMDIR="/usr/portage/rpm" RUBYOPT="-rauto_gem" RUBY_TARGETS="ruby18 ruby19" SESSION_MANAGER="local/ftn.caotus.ru:@/tmp/.ICE-unix/2296,unix/ftn.caotus.ru:/tmp/.ICE-unix/2296" SHELL="/bin/bash" SHLVL="3" SSH_AGENT_PID="2301" SSH_AUTH_SOCK="/tmp/gpg-Ycxizx/S.gpg-agent.ssh" SYMLINK_LIB="yes" SYNC="rsync://rsync.mydomain.ru/gentoo-portage/" TERM="xterm" TNS_ADMIN="/etc/oracle/" UNINSTALL_IGNORE="/lib/modules/*" USE="X a52 ac3 acl alsa amd64 avi berkdb bold bzip2 cdr cli consolekit cracklib crypt cups cxx dbus djvu dri dvd flac fortran gdbm gif gtk iconv jpeg jpeg2k lock mmx modules mp3 mudflap multilib ncurses nls nptl ogg openmp pam pcre pdf png policykit pppd qt3support readline session sse sse2 ssl tcpd thunar tiff udev unicode utf8 vorbis xcb xulrunner zlib" ALSA_CARDS="ali5451 als4000 atiixp atiixp-modem bt87x ca0106 cmipci emu10k1x ens1370 ens1371 es1938 es1968 fm801 hda-intel intel8x0 intel8x0m maestro3 trident usb-audio via82xx via82xx-modem ymfpci" ALSA_PCM_PLUGINS="adpcm alaw asym copy dmix dshare dsnoop empty extplug file hooks iec958 ioplug ladspa lfloat linear meter mmap_emul mulaw multi null plug rate route share shm softvol" APACHE2_MODULES="actions alias auth_basic authn_alias authn_anon authn_dbm authn_default authn_file authz_dbm authz_default authz_groupfile authz_host authz_owner authz_user autoindex cache cgi cgid dav dav_fs dav_lock deflate dir disk_cache env expires ext_filter file_cache filter headers include info log_config logio mem_cache mime mime_magic negotiation rewrite setenvif speling status unique_id userdir usertrack vhost_alias" CALLIGRA_FEATURES="kexi words flow plan sheets stage tables krita karbon braindump" CAMERAS="ptp2" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" ELIBC="glibc" GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt gpsclock itrax mtk3301 nmea ntrip navcom oceanserver oldstyle oncore rtcm104v2 rtcm104v3 sirf superstar2 timing tsip tripmate tnt ubx" INPUT_DEVICES="evdev" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LIBREOFFICE_EXTENSIONS="presenter-console presenter-minimizer" LINGUAS="ru" PHP_TARGETS="php5-3" PYTHON_TARGETS="python3_2 python2_7" RUBY_TARGETS="ruby18 ruby19" USERLAND="GNU" VIDEO_CARDS="radeon" XTABLES_ADDONS="quota2 psd pknock lscan length2 ipv4options ipset ipp2p iface geoip fuzzy condition tee tarpit sysrq steal rawnat logmark ipmark dhcpmac delude chaos account" USER="ftn" USERLAND="GNU" USE_EXPAND="ALSA_CARDS ALSA_PCM_PLUGINS APACHE2_MODULES APACHE2_MPMS CALLIGRA_FEATURES CAMERAS COLLECTD_PLUGINS CROSSCOMPILE_OPTS CURL_SSL DRACUT_MODULES DVB_CARDS ELIBC FCDSL_CARDS FFTOOLS FOO2ZJS_DEVICES FRITZCAPI_CARDS GPSD_PROTOCOLS GRUB_PLATFORMS INPUT_DEVICES KERNEL LCD_DEVICES LIBREOFFICE_EXTENSIONS LINGUAS LIRC_DEVICES MISDN_CARDS NETBEANS_MODULES NGINX_MODULES_HTTP NGINX_MODULES_MAIL OFED_DRIVERS OPENMPI_FABRICS OPENMPI_OFED_FEATURES OPENMPI_RM PHP_TARGETS PYTHON_TARGETS QEMU_SOFTMMU_TARGETS QEMU_USER_TARGETS RUBY_TARGETS SANE_BACKENDS USERLAND VIDEO_CARDS VOICEMAIL_STORAGE XFCE_PLUGINS XTABLES_ADDONS" USE_EXPAND_HIDDEN="CROSSCOMPILE_OPTS ELIBC KERNEL USERLAND" USE_ORDER="env:pkg:conf:defaults:pkginternal:repo:env.d" VBOX_APP_HOME="/usr/lib64/virtualbox" VIDEO_CARDS="radeon" WINDOWID="56623151" XAUTHORITY="/home/ftn/.Xauthority" XDG_CONFIG_DIRS="/etc/xdg:/etc/xdg" XDG_DATA_DIRS="/usr/local/share:/usr/share:/usr/share" XDG_MENU_PREFIX="xfce-" XDG_SESSION_COOKIE="61b16b728b2c2559e6cf4af600003741-1347425535.497474-167628178" XSESSION="Xfce4" XTABLES_ADDONS="quota2 psd pknock lscan length2 ipv4options ipset ipp2p iface geoip fuzzy condition tee tarpit sysrq steal rawnat logmark ipmark dhcpmac delude chaos account"
apropos isn't specified by POSIX, so they're fairly free to make any tweaks they like. in this case, it takes a regular expression, not a plain string. your 2nd attempt did not escape things properly. your shell processed the \ which means apropos still saw just a +. to escape it, do: apropos '\+' or escape the backslash for the shell: apropos \\+ as the `apropos --help` states: The --regex option is enabled by default. which means this is functioning correctly
