diff options
author | Robin Gareus <robin@gareus.org> | 2014-03-11 15:48:13 +0100 |
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committer | Robin Gareus <robin@gareus.org> | 2014-03-11 15:48:41 +0100 |
commit | f6129ed0f4c4e485a22093e833d420b13a0af0cb (patch) | |
tree | 59999ccb381f874937661e8b2665739f2da585bf /tools | |
parent | 279aefc60e232475c771932744afc1304f0b92d5 (diff) |
prototype vfork exec-wrapper.
Diffstat (limited to 'tools')
-rw-r--r-- | tools/exec_wrapper.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/tools/exec_wrapper.c b/tools/exec_wrapper.c new file mode 100644 index 0000000000..ad7577b70c --- /dev/null +++ b/tools/exec_wrapper.c @@ -0,0 +1,94 @@ +#include <stdio.h> +#include <unistd.h> +#include <stdlib.h> +#include <string.h> +#include <fcntl.h> + +#ifndef STDIN_FILENO +#define STDIN_FILENO 0 +#endif +#ifndef STDOUT_FILENO +#define STDOUT_FILENO 1 +#endif +#ifndef STDERR_FILENO +#define STDERR_FILENO 2 +#endif + +extern char **environ; +static void close_fd (int *fd) { if ((*fd) >= 0) close (*fd); *fd = -1; } + +int main(int argc, char *argv[]) { + if (argc < 10) { + // TODO: if argv > 3, assume pok[] is given, notifify parent. + // usage() and a man-page (help2man) would not be bad, either :) + return -1; + } + + int pok[2]; + int pin[2]; + int pout[2]; + + pok[0] = atoi(argv[1]); + pok[1] = atoi(argv[2]); + pin[0] = atoi(argv[3]); + pin[1] = atoi(argv[4]); + pout[0] = atoi(argv[5]); + pout[1] = atoi(argv[6]); + + int stderr_mode = atoi(argv[7]); + int nicelevel = atoi(argv[8]); + + /* vfork()ed child process - exec external process */ + close_fd(&pok[0]); + fcntl(pok[1], F_SETFD, FD_CLOEXEC); + + close_fd(&pin[1]); + if (pin[0] != STDIN_FILENO) { + dup2(pin[0], STDIN_FILENO); + } + close_fd(&pin[0]); + close_fd(&pout[0]); + if (pout[1] != STDOUT_FILENO) { + dup2(pout[1], STDOUT_FILENO); + } + + if (stderr_mode == 2) { + /* merge STDERR into output */ + if (pout[1] != STDERR_FILENO) { + dup2(pout[1], STDERR_FILENO); + } + } else if (stderr_mode == 1) { + /* ignore STDERR */ + close(STDERR_FILENO); + } else { + /* keep STDERR */ + } + + if (pout[1] != STDOUT_FILENO && pout[1] != STDERR_FILENO) { + close_fd(&pout[1]); + } + + if (nicelevel !=0) { + nice(nicelevel); + } + + /* copy current environment */ + char **envp = NULL; + int i=0; + envp = (char **) calloc(1, sizeof(char*)); + for (i=0;environ[i];++i) { + envp[i] = strdup(environ[i]); + envp = (char **) realloc(envp, (i+2) * sizeof(char*)); + } + envp[i] = 0; + + /* all systems go */ + execve(argv[9], &argv[9], envp); + + /* if we reach here something went wrong.. */ + char buf = 0; + (void) write(pok[1], &buf, 1 ); + close_fd(&pok[1]); + exit(-1); + return -1; +} |