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Diffstat (limited to 'util.cxx')
| -rw-r--r-- | util.cxx | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/util.cxx b/util.cxx new file mode 100644 index 00000000..af953395 --- /dev/null +++ b/util.cxx @@ -0,0 +1,199 @@ +// Copyright (C) Andrew Tridgell 2002 (original file) +// Copyright (C) 2006 Red Hat Inc. (systemtap changes) +// +// 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., 675 Mass Ave, Cambridge, MA 02139, USA. + +#include "util.h" +#include <stdexcept> +#include <cerrno> + +extern "C" { +#include <sys/types.h> +#include <sys/stat.h> +#include <pwd.h> +#include <unistd.h> +#include <stdlib.h> +#include <fcntl.h> +} + +using namespace std; + + +// Return current users home directory or die. +const char * +get_home_directory(void) +{ + const char *p = getenv("HOME"); + if (p) + return p; + + struct passwd *pwd = getpwuid(getuid()); + if (pwd) + return pwd->pw_dir; + + throw runtime_error("Unable to determine home directory"); + return NULL; +} + + +// Copy a file. The copy is done via a temporary file and atomic +// rename. +int +copy_file(const char *src, const char *dest) +{ + int fd1, fd2; + char buf[10240]; + int n; + string tmp; + char *tmp_name; + mode_t mask; + + // Open the src file. + fd1 = open(src, O_RDONLY); + if (fd1 == -1) + return -1; + + // Open the temporary output file. + tmp = dest + string(".XXXXXX"); + tmp_name = (char *)tmp.c_str(); + fd2 = mkstemp(tmp_name); + if (fd2 == -1) + { + close(fd1); + return -1; + } + + // Copy the src file to the temporary output file. + while ((n = read(fd1, buf, sizeof(buf))) > 0) + { + if (write(fd2, buf, n) != n) + { + close(fd2); + close(fd1); + unlink(tmp_name); + return -1; + } + } + close(fd1); + + // Set the permissions on the temporary output file. + mask = umask(0); + fchmod(fd2, 0666 & ~mask); + umask(mask); + + // Close the temporary output file. The close can fail on NFS if + // out of space. + if (close(fd2) == -1) + { + unlink(tmp_name); + return -1; + } + + // Rename the temporary output file to the destination file. + unlink(dest); + if (rename(tmp_name, dest) == -1) + { + unlink(tmp_name); + return -1; + } + + return 0; +} + + +// Make sure a directory exists. +int +create_dir(const char *dir) +{ + struct stat st; + if (stat(dir, &st) == 0) + { + if (S_ISDIR(st.st_mode)) + return 0; + errno = ENOTDIR; + return 1; + } + + if (mkdir(dir, 0777) != 0 && errno != EEXIST) + return 1; + + return 0; +} + + +void +tokenize(const string& str, vector<string>& tokens, + const string& delimiters = " ") +{ + // Skip delimiters at beginning. + string::size_type lastPos = str.find_first_not_of(delimiters, 0); + // Find first "non-delimiter". + string::size_type pos = str.find_first_of(delimiters, lastPos); + + while (pos != string::npos || lastPos != string::npos) + { + // Found a token, add it to the vector. + tokens.push_back(str.substr(lastPos, pos - lastPos)); + // Skip delimiters. Note the "not_of" + lastPos = str.find_first_not_of(delimiters, pos); + // Find next "non-delimiter" + pos = str.find_first_of(delimiters, lastPos); + } +} + + +// Find an executable by name in $PATH. +bool +find_executable(const char *name, string& retpath) +{ + const char *p; + string path; + vector<string> dirs; + struct stat st1, st2; + + if (*name == '/') + { + retpath = name; + return true; + } + + p = getenv("PATH"); + if (!p) + return false; + path = p; + + // Split PATH up. + tokenize(path, dirs, string(":")); + + // Search the path looking for the first executable of the right name. + for (vector<string>::iterator i = dirs.begin(); i != dirs.end(); i++) + { + string fname = *i + "/" + name; + const char *f = fname.c_str(); + + // Look for a normal executable file. + if (access(f, X_OK) == 0 + && lstat(f, &st1) == 0 + && stat(f, &st2) == 0 + && S_ISREG(st2.st_mode)) + { + // Found it! + retpath = fname; + return true; + } + } + + return false; +} |