IO API: use fork+exec

diff --git a/tig.c b/tig.c
index 1fd4bc9c14afb1e073afea5f9b6534661adcae47..eab037fb7bcceef25029a09eae6674b1c26218a4 100644 (file)
--- a/tig.c
+++ b/tig.c
@@ -32,6 +32,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <sys/types.h>
+#include <sys/wait.h>
 #include <sys/stat.h>
 #include <unistd.h>
 #include <time.h>
@@ -144,7 +145,6 @@ enum format_flags {
        FORMAT_NONE             /* No replacement should be performed. */
 };
 
-static bool format_command(char dst[], const char *src[], enum format_flags flags);
 static bool format_argv(const char *dst[], const char *src[], enum format_flags flags);
 
 struct int_map {
@@ -270,48 +270,6 @@ suffixcmp(const char *str, int slen, const char *suffix)
        return suffixlen < len ? strcmp(str + len - suffixlen, suffix) : -1;
 }
 
-/* Shell quoting
- *
- * NOTE: The following is a slightly modified copy of the git project's shell
- * quoting routines found in the quote.c file.
- *
- * Help to copy the thing properly quoted for the shell safety.  any single
- * quote is replaced with '\'', any exclamation point is replaced with '\!',
- * and the whole thing is enclosed in a
- *
- * E.g.
- *  original     sq_quote     result
- *  name     ==> name      ==> 'name'
- *  a b      ==> a b       ==> 'a b'
- *  a'b      ==> a'\''b    ==> 'a'\''b'
- *  a!b      ==> a'\!'b    ==> 'a'\!'b'
- */
-
-static size_t
-sq_quote(char buf[SIZEOF_STR], size_t bufsize, const char *src)
-{
-       char c;
-
-#define BUFPUT(x) do { if (bufsize < SIZEOF_STR) buf[bufsize++] = (x); } while (0)
-
-       BUFPUT('\'');
-       while ((c = *src++)) {
-               if (c == '\'' || c == '!') {
-                       BUFPUT('\'');
-                       BUFPUT('\\');
-                       BUFPUT(c);
-                       BUFPUT('\'');
-               } else {
-                       BUFPUT(c);
-               }
-       }
-       BUFPUT('\'');
-
-       if (bufsize < SIZEOF_STR)
-               buf[bufsize] = 0;
-
-       return bufsize;
-}
 
 static bool
 argv_from_string(const char *argv[SIZEOF_ARG], int *argc, char *cmd)
@@ -359,7 +317,7 @@ enum io_type {
 struct io {
        enum io_type type;      /* The requested type of pipe. */
        const char *dir;        /* Directory from which to execute. */
-       FILE *pid;              /* Pipe for reading or writing. */
+       pid_t pid;              /* Pipe for reading or writing. */
        int pipe;               /* Pipe end for reading or writing. */
        int error;              /* Error status. */
        const char *argv[SIZEOF_ARG];   /* Shell command arguments. */
@@ -374,7 +332,7 @@ static void
 reset_io(struct io *io)
 {
        io->pipe = -1;
-       io->pid = NULL;
+       io->pid = 0;
        io->buf = io->bufpos = NULL;
        io->bufalloc = io->bufsize = 0;
        io->error = 0;
@@ -405,42 +363,89 @@ io_open(struct io *io, const char *name)
        return io->pipe != -1;
 }
 
+static bool
+kill_io(struct io *io)
+{
+       return kill(io->pid, SIGKILL) != -1;
+}
+
 static bool
 done_io(struct io *io)
 {
-       free(io->buf);
-       if (io->type == IO_FD)
+       pid_t pid = io->pid;
+
+       if (io->pipe != -1)
                close(io->pipe);
-       else if (io->type == IO_RD || io->type == IO_WR)
-               pclose(io->pid);
+       free(io->buf);
        reset_io(io);
+
+       while (pid > 0) {
+               int status;
+               pid_t waiting = waitpid(pid, &status, 0);
+
+               if (waiting < 0) {
+                       if (errno == EINTR)
+                               continue;
+                       report("waitpid failed (%s)", strerror(errno));
+                       return FALSE;
+               }
+
+               return waiting == pid &&
+                      !WIFSIGNALED(status) &&
+                      WIFEXITED(status) &&
+                      !WEXITSTATUS(status);
+       }
+
        return TRUE;
 }
 
 static bool
 start_io(struct io *io)
 {
-       char buf[SIZEOF_STR * 2];
-       size_t bufpos = 0;
+       int pipefds[2] = { -1, -1 };
 
        if (io->type == IO_FD)
                return TRUE;
 
-       if (io->dir && *io->dir &&
-           !string_format_from(buf, &bufpos, "cd %s;", io->dir))
+       if ((io->type == IO_RD || io->type == IO_WR) &&
+           pipe(pipefds) < 0)
                return FALSE;
 
-       if (!format_command(buf + bufpos, io->argv, FORMAT_NONE))
-               return FALSE;
+       if ((io->pid = fork())) {
+               if (pipefds[!(io->type == IO_WR)] != -1)
+                       close(pipefds[!(io->type == IO_WR)]);
+               if (io->pid != -1) {
+                       io->pipe = pipefds[!!(io->type == IO_WR)];
+                       return TRUE;
+               }
+
+       } else {
+               if (io->type != IO_FG) {
+                       int devnull = open("/dev/null", O_RDWR);
+                       int readfd  = io->type == IO_WR ? pipefds[0] : devnull;
+                       int writefd = io->type == IO_RD ? pipefds[1] : devnull;
+
+                       dup2(readfd,  STDIN_FILENO);
+                       dup2(writefd, STDOUT_FILENO);
+                       dup2(devnull, STDERR_FILENO);
+
+                       close(devnull);
+                       if (pipefds[0] != -1)
+                               close(pipefds[0]);
+                       if (pipefds[1] != -1)
+                               close(pipefds[1]);
+               }
 
-       if (io->type == IO_FG || io->type == IO_BG)
-               return system(buf) == 0;
+               if (io->dir && *io->dir && chdir(io->dir) == -1)
+                       die("Failed to change directory: %s", strerror(errno));
 
-       io->pid = popen(buf, io->type == IO_RD ? "r" : "w");
-       if (!io->pid)
-               return FALSE;
-       io->pipe = fileno(io->pid);
-       return io->pipe != -1;
+               execvp(io->argv[0], (char *const*) io->argv);
+               die("Failed to execute program: %s", strerror(errno));
+       }
+
+       if (pipefds[!!(io->type == IO_WR)] != -1)
+               close(pipefds[!!(io->type == IO_WR)]);
+       return FALSE;
 }
 
 static bool
@@ -2554,31 +2559,6 @@ format_argv(const char *dst_argv[], const char *src_argv[], enum format_flags fl
        return src_argv[argc] == NULL;
 }
 
-static bool
-format_command(char dst[], const char *src_argv[], enum format_flags flags)
-{
-       const char *dst_argv[SIZEOF_ARG * 2] = { NULL };
-       int bufsize = 0;
-       int argc;
-
-       if (!format_argv(dst_argv, src_argv, flags)) {
-               free_argv(dst_argv);
-               return FALSE;
-       }
-
-       for (argc = 0; dst_argv[argc] && bufsize < SIZEOF_STR; argc++) {
-               if (bufsize > 0)
-                       dst[bufsize++] = ' ';
-               bufsize = sq_quote(dst, bufsize, dst_argv[argc]);
-       }
-
-       if (bufsize < SIZEOF_STR)
-               dst[bufsize] = 0;
-       free_argv(dst_argv);
-
-       return src_argv[argc] == NULL && bufsize < SIZEOF_STR;
-}
-
 static void
 end_update(struct view *view, bool force)
 {
@@ -2588,6 +2568,8 @@ end_update(struct view *view, bool force)
                if (!force)
                        return;
        set_nonblocking_input(FALSE);
+       if (force)
+               kill_io(view->pipe);
        done_io(view->pipe);
        view->pipe = NULL;
 }