run-command.h

   1 #ifndef RUN_COMMAND_H
   2 #define RUN_COMMAND_H
   3
   4 enum {
   5         ERR_RUN_COMMAND_FORK = 10000,
   6         ERR_RUN_COMMAND_EXEC,
   7         ERR_RUN_COMMAND_PIPE,
   8         ERR_RUN_COMMAND_WAITPID,
   9         ERR_RUN_COMMAND_WAITPID_WRONG_PID,
  10         ERR_RUN_COMMAND_WAITPID_SIGNAL,
  11         ERR_RUN_COMMAND_WAITPID_NOEXIT,
  12 };
  13 #define IS_RUN_COMMAND_ERR(x) ((x) <= -ERR_RUN_COMMAND_FORK)
  14
  15 struct child_process {
  16         const char **argv;
  17         pid_t pid;
  18         /*
  19          * Using .in, .out, .err:
  20          * - Specify 0 for no redirections (child inherits stdin, stdout,
  21          *   stderr from parent).
  22          * - Specify -1 to have a pipe allocated as follows:
  23          *     .in: returns the writable pipe end; parent writes to it,
  24          *          the readable pipe end becomes child's stdin
  25          *     .out, .err: returns the readable pipe end; parent reads from
  26          *          it, the writable pipe end becomes child's stdout/stderr
  27          *   The caller of start_command() must close the returned FDs
  28          *   after it has completed reading from/writing to it!
  29          * - Specify > 0 to set a channel to a particular FD as follows:
  30          *     .in: a readable FD, becomes child's stdin
  31          *     .out: a writable FD, becomes child's stdout/stderr
  32          *     .err > 0 not supported
  33          *   The specified FD is closed by start_command(), even in case
  34          *   of errors!
  35          */
  36         int in;
  37         int out;
  38         int err;
  39         const char *dir;
  40         const char *const *env;
  41         unsigned no_stdin:1;
  42         unsigned no_stdout:1;
  43         unsigned no_stderr:1;
  44         unsigned git_cmd:1; /* if this is to be git sub-command */
  45         unsigned stdout_to_stderr:1;
  46         void (*preexec_cb)(void);
  47 };
  48
  49 int start_command(struct child_process *);
  50 int finish_command(struct child_process *);
  51 int run_command(struct child_process *);
  52
  53 #define RUN_COMMAND_NO_STDIN 1
  54 #define RUN_GIT_CMD          2  /*If this is to be git sub-command */
  55 #define RUN_COMMAND_STDOUT_TO_STDERR 4
  56 int run_command_v_opt(const char **argv, int opt);
  57
  58 /*
  59  * env (the environment) is to be formatted like environ: "VAR=VALUE".
  60  * To unset an environment variable use just "VAR".
  61  */
  62 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env);
  63
  64 /*
  65  * The purpose of the following functions is to feed a pipe by running
  66  * a function asynchronously and providing output that the caller reads.
  67  *
  68  * It is expected that no synchronization and mutual exclusion between
  69  * the caller and the feed function is necessary so that the function
  70  * can run in a thread without interfering with the caller.
  71  */
  72 struct async {
  73         /*
  74          * proc writes to fd and closes it;
  75          * returns 0 on success, non-zero on failure
  76          */
  77         int (*proc)(int fd, void *data);
  78         void *data;
  79         int out;        /* caller reads from here and closes it */
  80 #ifndef __MINGW32__
  81         pid_t pid;
  82 #else
  83         HANDLE tid;
  84         int fd_for_proc;
  85 #endif
  86 };
  87
  88 int start_async(struct async *async);
  89 int finish_async(struct async *async);
  90
  91 #endif