Andrew's git - gitweb.git/blob

   1#include "cache.h"
   2#include "run-command.h"
   3#include "exec_cmd.h"
   4
   5static inline void close_pair(int fd[2])
   6{
   7        close(fd[0]);
   8        close(fd[1]);
   9}
  10
  11static inline void dup_devnull(int to)
  12{
  13        int fd = open("/dev/null", O_RDWR);
  14        dup2(fd, to);
  15        close(fd);
  16}
  17
  18int start_command(struct child_process *cmd)
  19{
  20        int need_in, need_out, need_err;
  21        int fdin[2], fdout[2], fderr[2];
  22
  23        /*
  24         * In case of errors we must keep the promise to close FDs
  25         * that have been passed in via ->in and ->out.
  26         */
  27
  28        need_in = !cmd->no_stdin && cmd->in < 0;
  29        if (need_in) {
  30                if (pipe(fdin) < 0) {
  31                        if (cmd->out > 0)
  32                                close(cmd->out);
  33                        return -ERR_RUN_COMMAND_PIPE;
  34                }
  35                cmd->in = fdin[1];
  36        }
  37
  38        need_out = !cmd->no_stdout
  39                && !cmd->stdout_to_stderr
  40                && cmd->out < 0;
  41        if (need_out) {
  42                if (pipe(fdout) < 0) {
  43                        if (need_in)
  44                                close_pair(fdin);
  45                        else if (cmd->in)
  46                                close(cmd->in);
  47                        return -ERR_RUN_COMMAND_PIPE;
  48                }
  49                cmd->out = fdout[0];
  50        }
  51
  52        need_err = !cmd->no_stderr && cmd->err < 0;
  53        if (need_err) {
  54                if (pipe(fderr) < 0) {
  55                        if (need_in)
  56                                close_pair(fdin);
  57                        else if (cmd->in)
  58                                close(cmd->in);
  59                        if (need_out)
  60                                close_pair(fdout);
  61                        else if (cmd->out)
  62                                close(cmd->out);
  63                        return -ERR_RUN_COMMAND_PIPE;
  64                }
  65                cmd->err = fderr[0];
  66        }
  67
  68        cmd->pid = fork();
  69        if (cmd->pid < 0) {
  70                if (need_in)
  71                        close_pair(fdin);
  72                else if (cmd->in)
  73                        close(cmd->in);
  74                if (need_out)
  75                        close_pair(fdout);
  76                else if (cmd->out)
  77                        close(cmd->out);
  78                if (need_err)
  79                        close_pair(fderr);
  80                return -ERR_RUN_COMMAND_FORK;
  81        }
  82
  83        if (!cmd->pid) {
  84                if (cmd->no_stdin)
  85                        dup_devnull(0);
  86                else if (need_in) {
  87                        dup2(fdin[0], 0);
  88                        close_pair(fdin);
  89                } else if (cmd->in) {
  90                        dup2(cmd->in, 0);
  91                        close(cmd->in);
  92                }
  93
  94                if (cmd->no_stderr)
  95                        dup_devnull(2);
  96                else if (need_err) {
  97                        dup2(fderr[1], 2);
  98                        close_pair(fderr);
  99                }
 100
 101                if (cmd->no_stdout)
 102                        dup_devnull(1);
 103                else if (cmd->stdout_to_stderr)
 104                        dup2(2, 1);
 105                else if (need_out) {
 106                        dup2(fdout[1], 1);
 107                        close_pair(fdout);
 108                } else if (cmd->out > 1) {
 109                        dup2(cmd->out, 1);
 110                        close(cmd->out);
 111                }
 112
 113                if (cmd->dir && chdir(cmd->dir))
 114                        die("exec %s: cd to %s failed (%s)", cmd->argv[0],
 115                            cmd->dir, strerror(errno));
 116                if (cmd->env) {
 117                        for (; *cmd->env; cmd->env++) {
 118                                if (strchr(*cmd->env, '='))
 119                                        putenv((char*)*cmd->env);
 120                                else
 121                                        unsetenv(*cmd->env);
 122                        }
 123                }
 124                if (cmd->git_cmd) {
 125                        execv_git_cmd(cmd->argv);
 126                } else {
 127                        execvp(cmd->argv[0], (char *const*) cmd->argv);
 128                }
 129                die("exec %s failed.", cmd->argv[0]);
 130        }
 131
 132        if (need_in)
 133                close(fdin[0]);
 134        else if (cmd->in)
 135                close(cmd->in);
 136
 137        if (need_out)
 138                close(fdout[1]);
 139        else if (cmd->out)
 140                close(cmd->out);
 141
 142        if (need_err)
 143                close(fderr[1]);
 144
 145        return 0;
 146}
 147
 148static int wait_or_whine(pid_t pid)
 149{
 150        for (;;) {
 151                int status, code;
 152                pid_t waiting = waitpid(pid, &status, 0);
 153
 154                if (waiting < 0) {
 155                        if (errno == EINTR)
 156                                continue;
 157                        error("waitpid failed (%s)", strerror(errno));
 158                        return -ERR_RUN_COMMAND_WAITPID;
 159                }
 160                if (waiting != pid)
 161                        return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
 162                if (WIFSIGNALED(status))
 163                        return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
 164
 165                if (!WIFEXITED(status))
 166                        return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
 167                code = WEXITSTATUS(status);
 168                if (code)
 169                        return -code;
 170                return 0;
 171        }
 172}
 173
 174int finish_command(struct child_process *cmd)
 175{
 176        return wait_or_whine(cmd->pid);
 177}
 178
 179int run_command(struct child_process *cmd)
 180{
 181        int code = start_command(cmd);
 182        if (code)
 183                return code;
 184        return finish_command(cmd);
 185}
 186
 187static void prepare_run_command_v_opt(struct child_process *cmd,
 188                                      const char **argv,
 189                                      int opt)
 190{
 191        memset(cmd, 0, sizeof(*cmd));
 192        cmd->argv = argv;
 193        cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 194        cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 195        cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 196}
 197
 198int run_command_v_opt(const char **argv, int opt)
 199{
 200        struct child_process cmd;
 201        prepare_run_command_v_opt(&cmd, argv, opt);
 202        return run_command(&cmd);
 203}
 204
 205int run_command_v_opt_cd(const char **argv, int opt, const char *dir)
 206{
 207        struct child_process cmd;
 208        prepare_run_command_v_opt(&cmd, argv, opt);
 209        cmd.dir = dir;
 210        return run_command(&cmd);
 211}
 212
 213int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
 214{
 215        struct child_process cmd;
 216        prepare_run_command_v_opt(&cmd, argv, opt);
 217        cmd.dir = dir;
 218        cmd.env = env;
 219        return run_command(&cmd);
 220}
 221
 222int start_async(struct async *async)
 223{
 224        int pipe_out[2];
 225
 226        if (pipe(pipe_out) < 0)
 227                return error("cannot create pipe: %s", strerror(errno));
 228
 229        async->pid = fork();
 230        if (async->pid < 0) {
 231                error("fork (async) failed: %s", strerror(errno));
 232                close_pair(pipe_out);
 233                return -1;
 234        }
 235        if (!async->pid) {
 236                close(pipe_out[0]);
 237                exit(!!async->proc(pipe_out[1], async->data));
 238        }
 239        async->out = pipe_out[0];
 240        close(pipe_out[1]);
 241        return 0;
 242}
 243
 244int finish_async(struct async *async)
 245{
 246        int ret = 0;
 247
 248        if (wait_or_whine(async->pid))
 249                ret = error("waitpid (async) failed");
 250        return ret;
 251}