diff --git a/utils/.gitignore b/utils/.gitignore index 2f9143f2..c86a23ab 100644 --- a/utils/.gitignore +++ b/utils/.gitignore @@ -1,6 +1,7 @@ *.o calc cat +chroot chvideomode clear colormake diff --git a/utils/Makefile b/utils/Makefile index 66ff4919..edbb48e2 100644 --- a/utils/Makefile +++ b/utils/Makefile @@ -17,6 +17,7 @@ CXXFLAGS:=$(CXXFLAGS) -Wall -Wextra -fno-exceptions -fno-rtti BINARIES:=\ calc \ cat \ +chroot \ chvideomode \ clear \ colormake \ diff --git a/utils/chroot.cpp b/utils/chroot.cpp new file mode 100644 index 00000000..1ad7aafd --- /dev/null +++ b/utils/chroot.cpp @@ -0,0 +1,116 @@ +/******************************************************************************* + + Copyright(C) Jonas 'Sortie' Termansen 2013. + + 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 3 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, see . + + chroot.cpp + Runs a process with another root directory. + +*******************************************************************************/ + +#include +#include +#include +#include +#include +#include + +#if !defined(VERSIONSTR) +#define VERSIONSTR "unknown version" +#endif + +void CompactArguments(int* argc, char*** argv) +{ + for ( int i = 0; i < *argc; i++ ) + while ( i < *argc && !(*argv)[i] ) + { + for ( int n = i; n < *argc; n++ ) + (*argv)[n] = (*argv)[n+1]; + (*argc)--; + } +} + +void Usage(FILE* fp, const char* argv0) +{ + fprintf(fp, "Usage: %s [OPTION]... ROOT [CMD] [ARGUMENT...]\n", argv0); +} + +void Help(FILE* fp, const char* argv0) +{ + Usage(fp, argv0); +} + +void Version(FILE* fp, const char* argv0) +{ + fprintf(fp, "%s (Sortix) %s\n", argv0, VERSIONSTR); + fprintf(fp, "License GPLv3+: GNU GPL version 3 or later .\n"); + fprintf(fp, "This is free software: you are free to change and redistribute it.\n"); + fprintf(fp, "There is NO WARRANTY, to the extent permitted by law.\n"); +} + +int main(int argc, char* argv[]) +{ + const char* argv0 = argv[0]; + for ( int i = 1; i < argc; i++ ) + { + const char* arg = argv[i]; + if ( arg[0] != '-' ) + continue; + argv[i] = NULL; + if ( !strcmp(arg, "--") ) + break; + if ( arg[1] != '-' ) + { + while ( char c = *++arg ) switch ( c ) + { + default: + fprintf(stderr, "%s: unknown option -- '%c'\n", argv0, c); + Usage(stderr, argv0); + exit(1); + } + } + else if ( !strcmp(arg, "--help") ) { Help(stdout, argv0); exit(0); } + else if ( !strcmp(arg, "--usage") ) { Usage(stdout, argv0); exit(0); } + else if ( !strcmp(arg, "--version") ) { Version(stdout, argv0); exit(0); } + else + { + fprintf(stderr, "%s: unknown option: %s\n", argv0, arg); + Usage(stderr, argv0); + exit(1); + } + } + + CompactArguments(&argc, &argv); + + if ( argc < 2 ) + { + error(0, 0, "missing operand, expected new root directory"); + Usage(stdout, argv0); + exit(0); + } + + if ( chroot(argv[1]) != 0 ) + error(1, errno, "`%s'", argv[1]); + + if ( chdir("/.") != 0 ) + error(1, errno, "chdir: `%s/.'", argv[1]); + + char* default_argv[] = { (char*) "sh", (char*) NULL }; + + char** exec_argv = 3 <= argc ? argv + 2 : default_argv; + execvp(exec_argv[0], exec_argv); + + error(127, errno, "`%s'", exec_argv[0]); +}