diff options
Diffstat (limited to 'src/unistd')
| -rw-r--r-- | src/unistd/execat.c | 3 | ||||
| -rw-r--r-- | src/unistd/fexec.c | 191 |
2 files changed, 191 insertions, 3 deletions
diff --git a/src/unistd/execat.c b/src/unistd/execat.c index d80d24b..5c42d79 100644 --- a/src/unistd/execat.c +++ b/src/unistd/execat.c @@ -450,9 +450,6 @@ int execvpeat(int dirfd, const char* file, char* const argv[], char* const envp[ if (strchr(file, '/') || !*file) return execveat(dirfd, file, argv, envp, flags); - if (!*file) - return errno = ENOENT, -1; - path = getenv(PATH); if (path == NULL) { diff --git a/src/unistd/fexec.c b/src/unistd/fexec.c new file mode 100644 index 0000000..bf022e4 --- /dev/null +++ b/src/unistd/fexec.c @@ -0,0 +1,191 @@ +/** + * slibc — Yet another C library + * Copyright © 2015 Mattias Andrée (maandree@member.fsf.org) + * + * 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 <http://www.gnu.org/licenses/>. + */ +#include <unistd.h> +#include <stdarg.h> +#include <errno.h> +#include <alloca.h> +#include <string.h> +#include <stdlib.h> + + + +/** + * The current environment variables. + */ +extern char** environ; + + + +/** + * Common code for the `fexecl*` functions. + * + * @param fd The first argument of said functions. + * @param argv The rest of the arguments of said functions; + * may conclude `envp`. + * @param fetch_envp Whether `argv` includes `envp`. + * + * @throws Any error specified for execve(2). + */ +static void vexec(int fd, va_list argv, int fetch_envp) +{ + char* const* envp = environ; + size_t n = 0, i; + va_list args; + char** argv_; + + va_copy(args, argv); + while (n++, va_arg(args, char*) != NULL) + break; + + if (fetch_envp) + envp = va_arg(args, char* const*); + + argv_ = alloca(n * sizeof(char*)); + for (i = 0; i < n; i++) + argv_[i] = va_arg(argv, char*); + + fexecve(fd, argv_, envp); +} + + + +/** + * Replace the current process image with a new process image. + * + * This is a slibc extension. + * + * @param fd File descriptor for the file to execute. + * @param ... The arguments with which to execute the file. + * The arguments should have the type `const char*`. + * As a slibc extension, it can be empty. + * This list shall be terminated by a `NULL` sentinel. + * @return This function does not return on success, + * on error, -1 is returned and `errno` is + * set to describe the error. + * + * @throws Any error specified for execve(2). + */ +int fexecl(int fd, ... /*, NULL */) +{ + int saved_errno; + va_list argv; + va_start(argv, path); + vfexec(fd, argv, 0); + saved_errno = errno; + va_end(argv); + return errno = saved_errno, -1; +} + + +/** + * Replace the current process image with a new process image. + * + * This is a slibc extension. + * + * @param fd File descriptor for the file to execute. + * @param ... The arguments with which to execute the file. + * The arguments should have the type `const char*`. + * As a slibc extension, it can be empty. + * This list shall be terminated by a `NULL` sentinel. + * @param envp The list of environment variables the new program shall + * have set. Each element shall be formatted $name=$value. + * This list shall be `NULL`-terminated. The behaviour + * is system-dependant if this argument is `NULL`. + * @return This function does not return on success, + * on error, -1 is returned and `errno` is + * set to describe the error. + * + * @throws Any error specified for execve(2). + */ +int fexecle(int fd, ... /*, NULL, char* const envp[] */) +{ + int saved_errno; + va_list argv; + va_start(argv, path); + vfexec(fd, argv, 1); + saved_errno = errno; + va_end(argv); + return errno = saved_errno, -1; +} + + +/** + * Replace the current process image with a new process image. + * + * This is a slibc extension. + * + * @param fd File descriptor for the file to execute. + * @param argv The arguments with which to execute the file. + * This parameter should really have the type + * `const char* const[]`, but that probably not + * so because compiles take issue with casts + * adding const to any pointer in the type + * except the outmost pointer. This list shall + * be `NULL`-terminated. The behaviour is + * system-dependant if this argument is `NULL`. + * @return This function does not return on success, + * on error, -1 is returned and `errno` is + * set to describe the error. + * + * @throws Any error specified for execve(2). + */ +int fexecv(int fd, char* const argv[]) +{ + return fexecve(fd, argv, environ); +} + + +/** + * Replace the current process image with a new process image. + * + * @param fd File descriptor for the file to execute. + * @param argv The arguments with which to execute the file. + * This parameter should really have the type + * `const char* const[]`, but that probably not + * so because compiles take issue with casts + * adding const to any pointer in the type + * except the outmost pointer. This list shall + * be `NULL`-terminated. The behaviour is + * system-dependant if this argument is `NULL`. + * @param envp The list of environment variables the new program shall + * have set. Each element shall be formatted $name=$value. + * This list shall be `NULL`-terminated. The behaviour + * is system-dependant if this argument is `NULL`. + * @return This function does not return on success, + * on error, -1 is returned and `errno` is + * set to describe the error. + * + * @throws Any error specified for execve(2). + */ +int fexecve(int fd, char* const argv[], char* const envp[]) +{ + char pathname[sizeof("/proc/self/fd//") + 3 * sizeof(int)]; + int saved_errno; + + sprintf(pathname, "/proc/self/fd/%i/", fd); + + execve(pathname, argv, envp); + saved_errno = errno; + + if (access("/proc/", X_OK)) + saved_errno = ENOSYS; + + errno = saved_errno == ENOENT ? EBADF : saved_errno; + return -1; +} + |