sphinx.addnodesdocument)}( rawsourcechildren]( translations LanguagesNode)}(hhh](h pending_xref)}(hhh]docutils.nodesTextChinese (Simplified)}(hhparenthuba attributes}(ids]classes]names]dupnames]backrefs] refdomainstdreftypedoc reftarget$/translations/zh_CN/admin-guide/javamodnameN classnameN refexplicitutagnamehhh ubh)}(hhh]hChinese (Traditional)}(hhhh2ubah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget$/translations/zh_TW/admin-guide/javamodnameN classnameN refexplicituh1hhh ubh)}(hhh]hItalian}(hhhhFubah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget$/translations/it_IT/admin-guide/javamodnameN classnameN refexplicituh1hhh ubh)}(hhh]hJapanese}(hhhhZubah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget$/translations/ja_JP/admin-guide/javamodnameN classnameN refexplicituh1hhh ubh)}(hhh]hKorean}(hhhhnubah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget$/translations/ko_KR/admin-guide/javamodnameN classnameN refexplicituh1hhh ubh)}(hhh]hSpanish}(hhhhubah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget$/translations/sp_SP/admin-guide/javamodnameN classnameN refexplicituh1hhh ubeh}(h]h ]h"]h$]h&]current_languageEnglishuh1h hh _documenthsourceNlineNubhsection)}(hhh](htitle)}(h.Java(tm) Binary Kernel Support for Linux v1.03h]h.Java(tm) Binary Kernel Support for Linux v1.03}(hhhhhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhhh>/var/lib/git/docbuild/linux/Documentation/admin-guide/java.rsthKubh paragraph)}(hzLinux beats them ALL! While all other OS's are TALKING about direct support of Java Binaries in the OS, Linux is doing it!h]h|Linux beats them ALL! While all other OS’s are TALKING about direct support of Java Binaries in the OS, Linux is doing it!}(hhhhhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhhhhubh)}(hqYou can execute Java applications and Java Applets just like any other program after you have done the following:h]hqYou can execute Java applications and Java Applets just like any other program after you have done the following:}(hhhhhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhhhhubhenumerated_list)}(hhh](h list_item)}(hXYou MUST FIRST install the Java Developers Kit for Linux. The Java on Linux HOWTO gives the details on getting and installing this. This HOWTO can be found at: ftp://sunsite.unc.edu/pub/Linux/docs/HOWTO/Java-HOWTO You should also set up a reasonable CLASSPATH environment variable to use Java applications that make use of any nonstandard classes (not included in the same directory as the application itself). h](h)}(hYou MUST FIRST install the Java Developers Kit for Linux. The Java on Linux HOWTO gives the details on getting and installing this. This HOWTO can be found at:h]hYou MUST FIRST install the Java Developers Kit for Linux. The Java on Linux HOWTO gives the details on getting and installing this. This HOWTO can be found at:}(hhhhhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK hhubh block_quote)}(hhh]h)}(h5ftp://sunsite.unc.edu/pub/Linux/docs/HOWTO/Java-HOWTOh]h reference)}(hhh]h5ftp://sunsite.unc.edu/pub/Linux/docs/HOWTO/Java-HOWTO}(hhhhhhhNhNubah}(h]h ]h"]h$]h&]refurihuh1hhhubah}(h]h ]h"]h$]h&]uh1hhhhKhhubah}(h]h ]h"]h$]h&]uh1hhhubh)}(hYou should also set up a reasonable CLASSPATH environment variable to use Java applications that make use of any nonstandard classes (not included in the same directory as the application itself).h]hYou should also set up a reasonable CLASSPATH environment variable to use Java applications that make use of any nonstandard classes (not included in the same directory as the application itself).}(hjhjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhhubeh}(h]h ]h"]h$]h&]uh1hhhhhhhhNubh)}(hXoYou have to compile BINFMT_MISC either as a module or into the kernel (``CONFIG_BINFMT_MISC``) and set it up properly. If you choose to compile it as a module, you will have to insert it manually with modprobe/insmod, as kmod cannot easily be supported with binfmt_misc. Read the file 'binfmt_misc.txt' in this directory to know more about the configuration process. h]h)}(hXnYou have to compile BINFMT_MISC either as a module or into the kernel (``CONFIG_BINFMT_MISC``) and set it up properly. If you choose to compile it as a module, you will have to insert it manually with modprobe/insmod, as kmod cannot easily be supported with binfmt_misc. Read the file 'binfmt_misc.txt' in this directory to know more about the configuration process.h](hGYou have to compile BINFMT_MISC either as a module or into the kernel (}(hGYou have to compile BINFMT_MISC either as a module or into the kernel (hj+hhhNhNubhliteral)}(h``CONFIG_BINFMT_MISC``h]hCONFIG_BINFMT_MISC}(hhhj6hhhNhNubah}(h]h ]h"]h$]h&]uh1j4hj+ubhX) and set it up properly. If you choose to compile it as a module, you will have to insert it manually with modprobe/insmod, as kmod cannot easily be supported with binfmt_misc. Read the file ‘binfmt_misc.txt’ in this directory to know more about the configuration process.}(hX) and set it up properly. If you choose to compile it as a module, you will have to insert it manually with modprobe/insmod, as kmod cannot easily be supported with binfmt_misc. Read the file 'binfmt_misc.txt' in this directory to know more about the configuration process.hj+hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhKhj'ubah}(h]h ]h"]h$]h&]uh1hhhhhhhhNubh)}(hXVAdd the following configuration items to binfmt_misc (you should really have read ``binfmt_misc.txt`` now): support for Java applications:: ':Java:M::\xca\xfe\xba\xbe::/usr/local/bin/javawrapper:' support for executable Jar files:: ':ExecutableJAR:E::jar::/usr/local/bin/jarwrapper:' support for Java Applets:: ':Applet:E::html::/usr/bin/appletviewer:' or the following, if you want to be more selective:: ':Applet:M::`` in the first line (``<`` has to be the first character!) to let this work! For the compiled Java programs you need a wrapper script like the following (this is because Java is broken in case of the filename handling), again fix the path names, both in the script and in the above given configuration string. You, too, need the little program after the script. Compile like:: gcc -O2 -o javaclassname javaclassname.c and stick it to ``/usr/local/bin``. Both the javawrapper shellscript and the javaclassname program were supplied by Colin J. Watson . h](h)}(hAdd the following configuration items to binfmt_misc (you should really have read ``binfmt_misc.txt`` now): support for Java applications::h](hRAdd the following configuration items to binfmt_misc (you should really have read }(hRAdd the following configuration items to binfmt_misc (you should really have read hjYhhhNhNubj5)}(h``binfmt_misc.txt``h]hbinfmt_misc.txt}(hhhjbhhhNhNubah}(h]h ]h"]h$]h&]uh1j4hjYubh% now): support for Java applications:}(h% now): support for Java applications:hjYhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhKhjUubh literal_block)}(h8':Java:M::\xca\xfe\xba\xbe::/usr/local/bin/javawrapper:'h]h8':Java:M::\xca\xfe\xba\xbe::/usr/local/bin/javawrapper:'}(hhhj}ubah}(h]h ]h"]h$]h&] xml:spacepreserveuh1j{hhhK!hjUubh)}(h"support for executable Jar files::h]h!support for executable Jar files:}(h!support for executable Jar files:hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK#hjUubj|)}(h3':ExecutableJAR:E::jar::/usr/local/bin/jarwrapper:'h]h3':ExecutableJAR:E::jar::/usr/local/bin/jarwrapper:'}(hhhjubah}(h]h ]h"]h$]h&]jjuh1j{hhhK%hjUubh)}(hsupport for Java Applets::h]hsupport for Java Applets:}(hsupport for Java Applets:hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK'hjUubj|)}(h)':Applet:E::html::/usr/bin/appletviewer:'h]h)':Applet:E::html::/usr/bin/appletviewer:'}(hhhjubah}(h]h ]h"]h$]h&]jjuh1j{hhhK)hjUubh)}(h4or the following, if you want to be more selective::h]h3or the following, if you want to be more selective:}(h3or the following, if you want to be more selective:hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK+hjUubj|)}(h/':Applet:M::`` in the first line (``<`` has to be the first character!) to let this work!h](hcNote, that for the more selective applet support you have to modify existing html-files to contain }(hcNote, that for the more selective applet support you have to modify existing html-files to contain hjhhhNhNubj5)}(h````h]h }(hhhj"hhhNhNubah}(h]h ]h"]h$]h&]uh1j4hjubh in the first line (}(h in the first line (hjhhhNhNubj5)}(h``<``h]h<}(hhhj5hhhNhNubah}(h]h ]h"]h$]h&]uh1j4hjubh2 has to be the first character!) to let this work!}(h2 has to be the first character!) to let this work!hjhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhK3hjUubh)}(hFor the compiled Java programs you need a wrapper script like the following (this is because Java is broken in case of the filename handling), again fix the path names, both in the script and in the above given configuration string.h]hFor the compiled Java programs you need a wrapper script like the following (this is because Java is broken in case of the filename handling), again fix the path names, both in the script and in the above given configuration string.}(hjPhjNhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK7hjUubh)}(hBYou, too, need the little program after the script. Compile like::h]hAYou, too, need the little program after the script. Compile like:}(hAYou, too, need the little program after the script. Compile like:hj\hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjUubh)}(h#and stick it to ``/usr/local/bin``.h](hand stick it to }(hand stick it to hjyhhhNhNubj5)}(h``/usr/local/bin``h]h/usr/local/bin}(hhhjhhhNhNubah}(h]h ]h"]h$]h&]uh1j4hjyubh.}(h.hjyhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhK@hjUubh)}(hrBoth the javawrapper shellscript and the javaclassname program were supplied by Colin J. Watson .h](haBoth the javawrapper shellscript and the javaclassname program were supplied by Colin J. Watson <}(haBoth the javawrapper shellscript and the javaclassname program were supplied by Colin J. Watson .}(h>.hjhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhKBhjUubeh}(h]h ]h"]h$]h&]uh1hhhhhhhhNubeh}(h]h ]h"]h$]h&]enumtypearabicprefixhsuffixjuh1hhhhhhhhK ubh)}(hJavawrapper shell script:h]hJavawrapper shell script:}(hjhjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKEhhhhubj|)}(hX #!/bin/bash # /usr/local/bin/javawrapper - the wrapper for binfmt_misc/java if [ -z "$1" ]; then exec 1>&2 echo Usage: $0 class-file exit 1 fi CLASS=$1 FQCLASS=`/usr/local/bin/javaclassname $1` FQCLASSN=`echo $FQCLASS | sed -e 's/^.*\.\([^.]*\)$/\1/'` FQCLASSP=`echo $FQCLASS | sed -e 's-\.-/-g' -e 's-^[^/]*$--' -e 's-/[^/]*$--'` # for example: # CLASS=Test.class # FQCLASS=foo.bar.Test # FQCLASSN=Test # FQCLASSP=foo/bar unset CLASSBASE declare -i LINKLEVEL=0 while :; do if [ "`basename $CLASS .class`" == "$FQCLASSN" ]; then # See if this directory works straight off cd -L `dirname $CLASS` CLASSDIR=$PWD cd $OLDPWD if echo $CLASSDIR | grep -q "$FQCLASSP$"; then CLASSBASE=`echo $CLASSDIR | sed -e "s.$FQCLASSP$.."` break; fi # Try dereferencing the directory name cd -P `dirname $CLASS` CLASSDIR=$PWD cd $OLDPWD if echo $CLASSDIR | grep -q "$FQCLASSP$"; then CLASSBASE=`echo $CLASSDIR | sed -e "s.$FQCLASSP$.."` break; fi # If no other possible filename exists if [ ! -L $CLASS ]; then exec 1>&2 echo $0: echo " $CLASS should be in a" \ "directory tree called $FQCLASSP" exit 1 fi fi if [ ! -L $CLASS ]; then break; fi # Go down one more level of symbolic links let LINKLEVEL+=1 if [ $LINKLEVEL -gt 5 ]; then exec 1>&2 echo $0: echo " Too many symbolic links encountered" exit 1 fi CLASS=`ls --color=no -l $CLASS | sed -e 's/^.* \([^ ]*\)$/\1/'` done if [ -z "$CLASSBASE" ]; then if [ -z "$FQCLASSP" ]; then GOODNAME=$FQCLASSN.class else GOODNAME=$FQCLASSP/$FQCLASSN.class fi exec 1>&2 echo $0: echo " $FQCLASS should be in a file called $GOODNAME" exit 1 fi if ! echo $CLASSPATH | grep -q "^\(.*:\)*$CLASSBASE\(:.*\)*"; then # class is not in CLASSPATH, so prepend dir of class to CLASSPATH if [ -z "${CLASSPATH}" ] ; then export CLASSPATH=$CLASSBASE else export CLASSPATH=$CLASSBASE:$CLASSPATH fi fi shift /usr/bin/java $FQCLASS "$@"h]hX #!/bin/bash # /usr/local/bin/javawrapper - the wrapper for binfmt_misc/java if [ -z "$1" ]; then exec 1>&2 echo Usage: $0 class-file exit 1 fi CLASS=$1 FQCLASS=`/usr/local/bin/javaclassname $1` FQCLASSN=`echo $FQCLASS | sed -e 's/^.*\.\([^.]*\)$/\1/'` FQCLASSP=`echo $FQCLASS | sed -e 's-\.-/-g' -e 's-^[^/]*$--' -e 's-/[^/]*$--'` # for example: # CLASS=Test.class # FQCLASS=foo.bar.Test # FQCLASSN=Test # FQCLASSP=foo/bar unset CLASSBASE declare -i LINKLEVEL=0 while :; do if [ "`basename $CLASS .class`" == "$FQCLASSN" ]; then # See if this directory works straight off cd -L `dirname $CLASS` CLASSDIR=$PWD cd $OLDPWD if echo $CLASSDIR | grep -q "$FQCLASSP$"; then CLASSBASE=`echo $CLASSDIR | sed -e "s.$FQCLASSP$.."` break; fi # Try dereferencing the directory name cd -P `dirname $CLASS` CLASSDIR=$PWD cd $OLDPWD if echo $CLASSDIR | grep -q "$FQCLASSP$"; then CLASSBASE=`echo $CLASSDIR | sed -e "s.$FQCLASSP$.."` break; fi # If no other possible filename exists if [ ! -L $CLASS ]; then exec 1>&2 echo $0: echo " $CLASS should be in a" \ "directory tree called $FQCLASSP" exit 1 fi fi if [ ! -L $CLASS ]; then break; fi # Go down one more level of symbolic links let LINKLEVEL+=1 if [ $LINKLEVEL -gt 5 ]; then exec 1>&2 echo $0: echo " Too many symbolic links encountered" exit 1 fi CLASS=`ls --color=no -l $CLASS | sed -e 's/^.* \([^ ]*\)$/\1/'` done if [ -z "$CLASSBASE" ]; then if [ -z "$FQCLASSP" ]; then GOODNAME=$FQCLASSN.class else GOODNAME=$FQCLASSP/$FQCLASSN.class fi exec 1>&2 echo $0: echo " $FQCLASS should be in a file called $GOODNAME" exit 1 fi if ! echo $CLASSPATH | grep -q "^\(.*:\)*$CLASSBASE\(:.*\)*"; then # class is not in CLASSPATH, so prepend dir of class to CLASSPATH if [ -z "${CLASSPATH}" ] ; then export CLASSPATH=$CLASSBASE else export CLASSPATH=$CLASSBASE:$CLASSPATH fi fi shift /usr/bin/java $FQCLASS "$@"}(hhhjubah}(h]h ]h"]h$]h&]jjforcelanguageshhighlight_args}uh1j{hhhKGhhhhubh)}(hjavaclassname.c:h]hjavaclassname.c:}(hjhjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhhhhubj|)}(hX/* javaclassname.c * * Extracts the class name from a Java class file; intended for use in a Java * wrapper of the type supported by the binfmt_misc option in the Linux kernel. * * Copyright (C) 1999 Colin J. Watson . * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include #include #include #include /* From Sun's Java VM Specification, as tag entries in the constant pool. */ #define CP_UTF8 1 #define CP_INTEGER 3 #define CP_FLOAT 4 #define CP_LONG 5 #define CP_DOUBLE 6 #define CP_CLASS 7 #define CP_STRING 8 #define CP_FIELDREF 9 #define CP_METHODREF 10 #define CP_INTERFACEMETHODREF 11 #define CP_NAMEANDTYPE 12 #define CP_METHODHANDLE 15 #define CP_METHODTYPE 16 #define CP_INVOKEDYNAMIC 18 /* Define some commonly used error messages */ #define seek_error() error("%s: Cannot seek\n", program) #define corrupt_error() error("%s: Class file corrupt\n", program) #define eof_error() error("%s: Unexpected end of file\n", program) #define utf8_error() error("%s: Only ASCII 1-255 supported\n", program); char *program; long *pool; u_int8_t read_8(FILE *classfile); u_int16_t read_16(FILE *classfile); void skip_constant(FILE *classfile, u_int16_t *cur); void error(const char *format, ...); int main(int argc, char **argv); /* Reads in an unsigned 8-bit integer. */ u_int8_t read_8(FILE *classfile) { int b = fgetc(classfile); if(b == EOF) eof_error(); return (u_int8_t)b; } /* Reads in an unsigned 16-bit integer. */ u_int16_t read_16(FILE *classfile) { int b1, b2; b1 = fgetc(classfile); if(b1 == EOF) eof_error(); b2 = fgetc(classfile); if(b2 == EOF) eof_error(); return (u_int16_t)((b1 << 8) | b2); } /* Reads in a value from the constant pool. */ void skip_constant(FILE *classfile, u_int16_t *cur) { u_int16_t len; int seekerr = 1; pool[*cur] = ftell(classfile); switch(read_8(classfile)) { case CP_UTF8: len = read_16(classfile); seekerr = fseek(classfile, len, SEEK_CUR); break; case CP_CLASS: case CP_STRING: case CP_METHODTYPE: seekerr = fseek(classfile, 2, SEEK_CUR); break; case CP_METHODHANDLE: seekerr = fseek(classfile, 3, SEEK_CUR); break; case CP_INTEGER: case CP_FLOAT: case CP_FIELDREF: case CP_METHODREF: case CP_INTERFACEMETHODREF: case CP_NAMEANDTYPE: case CP_INVOKEDYNAMIC: seekerr = fseek(classfile, 4, SEEK_CUR); break; case CP_LONG: case CP_DOUBLE: seekerr = fseek(classfile, 8, SEEK_CUR); ++(*cur); break; default: corrupt_error(); } if(seekerr) seek_error(); } void error(const char *format, ...) { va_list ap; va_start(ap, format); vfprintf(stderr, format, ap); va_end(ap); exit(1); } int main(int argc, char **argv) { FILE *classfile; u_int16_t cp_count, i, this_class, classinfo_ptr; u_int8_t length; program = argv[0]; if(!argv[1]) error("%s: Missing input file\n", program); classfile = fopen(argv[1], "rb"); if(!classfile) error("%s: Error opening %s\n", program, argv[1]); if(fseek(classfile, 8, SEEK_SET)) /* skip magic and version numbers */ seek_error(); cp_count = read_16(classfile); pool = calloc(cp_count, sizeof(long)); if(!pool) error("%s: Out of memory for constant pool\n", program); for(i = 1; i < cp_count; ++i) skip_constant(classfile, &i); if(fseek(classfile, 2, SEEK_CUR)) /* skip access flags */ seek_error(); this_class = read_16(classfile); if(this_class < 1 || this_class >= cp_count) corrupt_error(); if(!pool[this_class] || pool[this_class] == -1) corrupt_error(); if(fseek(classfile, pool[this_class] + 1, SEEK_SET)) seek_error(); classinfo_ptr = read_16(classfile); if(classinfo_ptr < 1 || classinfo_ptr >= cp_count) corrupt_error(); if(!pool[classinfo_ptr] || pool[classinfo_ptr] == -1) corrupt_error(); if(fseek(classfile, pool[classinfo_ptr] + 1, SEEK_SET)) seek_error(); length = read_16(classfile); for(i = 0; i < length; ++i) { u_int8_t x = read_8(classfile); if((x & 0x80) || !x) { if((x & 0xE0) == 0xC0) { u_int8_t y = read_8(classfile); if((y & 0xC0) == 0x80) { int c = ((x & 0x1f) << 6) + (y & 0x3f); if(c) putchar(c); else utf8_error(); } else utf8_error(); } else utf8_error(); } else if(x == '/') putchar('.'); else putchar(x); } putchar('\n'); free(pool); fclose(classfile); return 0; }h]hX/* javaclassname.c * * Extracts the class name from a Java class file; intended for use in a Java * wrapper of the type supported by the binfmt_misc option in the Linux kernel. * * Copyright (C) 1999 Colin J. Watson . * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include #include #include #include /* From Sun's Java VM Specification, as tag entries in the constant pool. */ #define CP_UTF8 1 #define CP_INTEGER 3 #define CP_FLOAT 4 #define CP_LONG 5 #define CP_DOUBLE 6 #define CP_CLASS 7 #define CP_STRING 8 #define CP_FIELDREF 9 #define CP_METHODREF 10 #define CP_INTERFACEMETHODREF 11 #define CP_NAMEANDTYPE 12 #define CP_METHODHANDLE 15 #define CP_METHODTYPE 16 #define CP_INVOKEDYNAMIC 18 /* Define some commonly used error messages */ #define seek_error() error("%s: Cannot seek\n", program) #define corrupt_error() error("%s: Class file corrupt\n", program) #define eof_error() error("%s: Unexpected end of file\n", program) #define utf8_error() error("%s: Only ASCII 1-255 supported\n", program); char *program; long *pool; u_int8_t read_8(FILE *classfile); u_int16_t read_16(FILE *classfile); void skip_constant(FILE *classfile, u_int16_t *cur); void error(const char *format, ...); int main(int argc, char **argv); /* Reads in an unsigned 8-bit integer. */ u_int8_t read_8(FILE *classfile) { int b = fgetc(classfile); if(b == EOF) eof_error(); return (u_int8_t)b; } /* Reads in an unsigned 16-bit integer. */ u_int16_t read_16(FILE *classfile) { int b1, b2; b1 = fgetc(classfile); if(b1 == EOF) eof_error(); b2 = fgetc(classfile); if(b2 == EOF) eof_error(); return (u_int16_t)((b1 << 8) | b2); } /* Reads in a value from the constant pool. */ void skip_constant(FILE *classfile, u_int16_t *cur) { u_int16_t len; int seekerr = 1; pool[*cur] = ftell(classfile); switch(read_8(classfile)) { case CP_UTF8: len = read_16(classfile); seekerr = fseek(classfile, len, SEEK_CUR); break; case CP_CLASS: case CP_STRING: case CP_METHODTYPE: seekerr = fseek(classfile, 2, SEEK_CUR); break; case CP_METHODHANDLE: seekerr = fseek(classfile, 3, SEEK_CUR); break; case CP_INTEGER: case CP_FLOAT: case CP_FIELDREF: case CP_METHODREF: case CP_INTERFACEMETHODREF: case CP_NAMEANDTYPE: case CP_INVOKEDYNAMIC: seekerr = fseek(classfile, 4, SEEK_CUR); break; case CP_LONG: case CP_DOUBLE: seekerr = fseek(classfile, 8, SEEK_CUR); ++(*cur); break; default: corrupt_error(); } if(seekerr) seek_error(); } void error(const char *format, ...) { va_list ap; va_start(ap, format); vfprintf(stderr, format, ap); va_end(ap); exit(1); } int main(int argc, char **argv) { FILE *classfile; u_int16_t cp_count, i, this_class, classinfo_ptr; u_int8_t length; program = argv[0]; if(!argv[1]) error("%s: Missing input file\n", program); classfile = fopen(argv[1], "rb"); if(!classfile) error("%s: Error opening %s\n", program, argv[1]); if(fseek(classfile, 8, SEEK_SET)) /* skip magic and version numbers */ seek_error(); cp_count = read_16(classfile); pool = calloc(cp_count, sizeof(long)); if(!pool) error("%s: Out of memory for constant pool\n", program); for(i = 1; i < cp_count; ++i) skip_constant(classfile, &i); if(fseek(classfile, 2, SEEK_CUR)) /* skip access flags */ seek_error(); this_class = read_16(classfile); if(this_class < 1 || this_class >= cp_count) corrupt_error(); if(!pool[this_class] || pool[this_class] == -1) corrupt_error(); if(fseek(classfile, pool[this_class] + 1, SEEK_SET)) seek_error(); classinfo_ptr = read_16(classfile); if(classinfo_ptr < 1 || classinfo_ptr >= cp_count) corrupt_error(); if(!pool[classinfo_ptr] || pool[classinfo_ptr] == -1) corrupt_error(); if(fseek(classfile, pool[classinfo_ptr] + 1, SEEK_SET)) seek_error(); length = read_16(classfile); for(i = 0; i < length; ++i) { u_int8_t x = read_8(classfile); if((x & 0x80) || !x) { if((x & 0xE0) == 0xC0) { u_int8_t y = read_8(classfile); if((y & 0xC0) == 0x80) { int c = ((x & 0x1f) << 6) + (y & 0x3f); if(c) putchar(c); else utf8_error(); } else utf8_error(); } else utf8_error(); } else if(x == '/') putchar('.'); else putchar(x); } putchar('\n'); free(pool); fclose(classfile); return 0; }}(hhhjubah}(h]h ]h"]h$]h&]jjjjcj}uh1j{hhhKhhhhubh)}(h jarwrapper::h]h jarwrapper:}(h jarwrapper:hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMohhhhubj|)}(h\#!/bin/bash # /usr/local/java/bin/jarwrapper - the wrapper for binfmt_misc/jar java -jar $1h]h\#!/bin/bash # /usr/local/java/bin/jarwrapper - the wrapper for binfmt_misc/jar java -jar $1}(hhhjubah}(h]h ]h"]h$]h&]jjuh1j{hhhMqhhhhubh)}(h\Now simply ``chmod +x`` the ``.class``, ``.jar`` and/or ``.html`` files you want to execute.h](h Now simply }(h Now simply hj+hhhNhNubj5)}(h ``chmod +x``h]hchmod +x}(hhhj4hhhNhNubah}(h]h ]h"]h$]h&]uh1j4hj+ubh the }(h the hj+hhhNhNubj5)}(h ``.class``h]h.class}(hhhjGhhhNhNubah}(h]h ]h"]h$]h&]uh1j4hj+ubh, }(h, hj+hhhNhNubj5)}(h``.jar``h]h.jar}(hhhjZhhhNhNubah}(h]h ]h"]h$]h&]uh1j4hj+ubh and/or }(h and/or hj+hhhNhNubj5)}(h ``.html``h]h.html}(hhhjmhhhNhNubah}(h]h ]h"]h$]h&]uh1j4hj+ubh files you want to execute.}(h files you want to execute.hj+hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhMwhhhhubh)}(hXTo add a Java program to your path best put a symbolic link to the main .class file into /usr/bin (or another place you like) omitting the .class extension. The directory containing the original .class file will be added to your CLASSPATH during execution.h]hXTo add a Java program to your path best put a symbolic link to the main .class file into /usr/bin (or another place you like) omitting the .class extension. The directory containing the original .class file will be added to your CLASSPATH during execution.}(hjhjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMzhhhhubh)}(h^To test your new setup, enter in the following simple Java app, and name it "HelloWorld.java":h]hbTo test your new setup, enter in the following simple Java app, and name it “HelloWorld.java”:}(hjhjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhhhhubj|)}(hclass HelloWorld { public static void main(String args[]) { System.out.println("Hello World!"); } }h]hclass HelloWorld { public static void main(String args[]) { System.out.println("Hello World!"); } }}(hhhjubah}(h]h ]h"]h$]h&]jjjjjavaj}uh1j{hhhMhhhhubh)}(h"Now compile the application with::h]h!Now compile the application with:}(h!Now compile the application with:hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhhhhubj|)}(hjavac HelloWorld.javah]hjavac HelloWorld.java}(hhhjubah}(h]h ]h"]h$]h&]jjuh1j{hhhMhhhhubh)}(h9Set the executable permissions of the binary file, with::h]h8Set the executable permissions of the binary file, with:}(h8Set the executable permissions of the binary file, with:hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhhhhubj|)}(hchmod 755 HelloWorld.classh]hchmod 755 HelloWorld.class}(hhhjubah}(h]h ]h"]h$]h&]jjuh1j{hhhMhhhhubh)}(hAnd then execute it::h]hAnd then execute it:}(hAnd then execute it:hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhhhhubj|)}(h./HelloWorld.classh]h./HelloWorld.class}(hhhjubah}(h]h ]h"]h$]h&]jjuh1j{hhhMhhhhubh)}(hhTo execute Java Jar files, simple chmod the ``*.jar`` files to include the execution bit, then just do::h](h,To execute Java Jar files, simple chmod the }(h,To execute Java Jar files, simple chmod the hj hhhNhNubj5)}(h ``*.jar``h]h*.jar}(hhhjhhhNhNubah}(h]h ]h"]h$]h&]uh1j4hj ubh2 files to include the execution bit, then just do:}(h2 files to include the execution bit, then just do:hj hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhMhhhhubj|)}(h./Application.jarh]h./Application.jar}(hhhj+ubah}(h]h ]h"]h$]h&]jjuh1j{hhhMhhhhubh)}(hgTo execute Java Applets, simple chmod the ``*.html`` files to include the execution bit, then just do::h](h*To execute Java Applets, simple chmod the }(h*To execute Java Applets, simple chmod the hj9hhhNhNubj5)}(h ``*.html``h]h*.html}(hhhjBhhhNhNubah}(h]h ]h"]h$]h&]uh1j4hj9ubh2 files to include the execution bit, then just do:}(h2 files to include the execution bit, then just do:hj9hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhMhhhhubj|)}(h ./Applet.htmlh]h ./Applet.html}(hhhj[ubah}(h]h ]h"]h$]h&]jjuh1j{hhhMhhhhubh)}(horiginally by Brian A. Lantz, brian@lantz.com heavily edited for binfmt_misc by Richard Günther new scripts by Colin J. Watson added executable Jar file support by Kurt Huwig h](horiginally by Brian A. Lantz, }(horiginally by Brian A. Lantz, hjihhhNhNubh)}(hbrian@lantz.comh]hbrian@lantz.com}(hhhjrhhhNhNubah}(h]h ]h"]h$]h&]refurimailto:brian@lantz.comuh1hhjiubhT heavily edited for binfmt_misc by Richard Günther new scripts by Colin J. Watson <}(hT heavily edited for binfmt_misc by Richard Günther new scripts by Colin J. 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