run-command.c

   1 #include "cache.h"
   2 #include "run-command.h"
   3 #include "exec_cmd.h"
   4
   5 static inline void close_pair(int fd[2])
   6 {
   7         close(fd[0]);
   8         close(fd[1]);
   9 }
  10
  11 static inline void dup_devnull(int to)
  12 {
  13         int fd = open("/dev/null", O_RDWR);
  14         dup2(fd, to);
  15         close(fd);
  16 }
  17
  18 int start_command(struct child_process *cmd)
  19 {
  20         int need_in, need_out;
  21         int fdin[2], fdout[2];
  22
  23         need_in = !cmd->no_stdin && cmd->in < 0;
  24         if (need_in) {
  25                 if (pipe(fdin) < 0)
  26                         return -ERR_RUN_COMMAND_PIPE;
  27                 cmd->in = fdin[1];
  28                 cmd->close_in = 1;
  29         }
  30
  31         need_out = !cmd->no_stdout
  32                 && !cmd->stdout_to_stderr
  33                 && cmd->out < 0;
  34         if (need_out) {
  35                 if (pipe(fdout) < 0) {
  36                         if (need_in)
  37                                 close_pair(fdin);
  38                         return -ERR_RUN_COMMAND_PIPE;
  39                 }
  40                 cmd->out = fdout[0];
  41                 cmd->close_out = 1;
  42         }
  43
  44         cmd->pid = fork();
  45         if (cmd->pid < 0) {
  46                 if (need_in)
  47                         close_pair(fdin);
  48                 if (need_out)
  49                         close_pair(fdout);
  50                 return -ERR_RUN_COMMAND_FORK;
  51         }
  52
  53         if (!cmd->pid) {
  54                 if (cmd->no_stdin)
  55                         dup_devnull(0);
  56                 else if (need_in) {
  57                         dup2(fdin[0], 0);
  58                         close_pair(fdin);
  59                 } else if (cmd->in) {
  60                         dup2(cmd->in, 0);
  61                         close(cmd->in);
  62                 }
  63
  64                 if (cmd->no_stdout)
  65                         dup_devnull(1);
  66                 else if (cmd->stdout_to_stderr)
  67                         dup2(2, 1);
  68                 else if (need_out) {
  69                         dup2(fdout[1], 1);
  70                         close_pair(fdout);
  71                 } else if (cmd->out > 1) {
  72                         dup2(cmd->out, 1);
  73                         close(cmd->out);
  74                 }
  75
  76                 if (cmd->dir && chdir(cmd->dir))
  77                         die("exec %s: cd to %s failed (%s)", cmd->argv[0],
  78                             cmd->dir, strerror(errno));
  79                 if (cmd->env) {
  80                         for (; *cmd->env; cmd->env++)
  81                                 putenv((char*)*cmd->env);
  82                 }
  83                 if (cmd->git_cmd) {
  84                         execv_git_cmd(cmd->argv);
  85                 } else {
  86                         execvp(cmd->argv[0], (char *const*) cmd->argv);
  87                 }
  88                 die("exec %s failed.", cmd->argv[0]);
  89         }
  90
  91         if (need_in)
  92                 close(fdin[0]);
  93         else if (cmd->in)
  94                 close(cmd->in);
  95
  96         if (need_out)
  97                 close(fdout[1]);
  98         else if (cmd->out > 1)
  99                 close(cmd->out);
 100
 101         return 0;
 102 }
 103
 104 int finish_command(struct child_process *cmd)
 105 {
 106         if (cmd->close_in)
 107                 close(cmd->in);
 108         if (cmd->close_out)
 109                 close(cmd->out);
 110
 111         for (;;) {
 112                 int status, code;
 113                 pid_t waiting = waitpid(cmd->pid, &status, 0);
 114
 115                 if (waiting < 0) {
 116                         if (errno == EINTR)
 117                                 continue;
 118                         error("waitpid failed (%s)", strerror(errno));
 119                         return -ERR_RUN_COMMAND_WAITPID;
 120                 }
 121                 if (waiting != cmd->pid)
 122                         return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
 123                 if (WIFSIGNALED(status))
 124                         return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
 125
 126                 if (!WIFEXITED(status))
 127                         return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
 128                 code = WEXITSTATUS(status);
 129                 if (code)
 130                         return -code;
 131                 return 0;
 132         }
 133 }
 134
 135 int run_command(struct child_process *cmd)
 136 {
 137         int code = start_command(cmd);
 138         if (code)
 139                 return code;
 140         return finish_command(cmd);
 141 }
 142
 143 static void prepare_run_command_v_opt(struct child_process *cmd,
 144                                       const char **argv,
 145                                       int opt)
 146 {
 147         memset(cmd, 0, sizeof(*cmd));
 148         cmd->argv = argv;
 149         cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 150         cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 151         cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 152 }
 153
 154 int run_command_v_opt(const char **argv, int opt)
 155 {
 156         struct child_process cmd;
 157         prepare_run_command_v_opt(&cmd, argv, opt);
 158         return run_command(&cmd);
 159 }
 160
 161 int run_command_v_opt_cd(const char **argv, int opt, const char *dir)
 162 {
 163         struct child_process cmd;
 164         prepare_run_command_v_opt(&cmd, argv, opt);
 165         cmd.dir = dir;
 166         return run_command(&cmd);
 167 }
 168
 169 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
 170 {
 171         struct child_process cmd;
 172         prepare_run_command_v_opt(&cmd, argv, opt);
 173         cmd.dir = dir;
 174         cmd.env = env;
 175         return run_command(&cmd);
 176 }