Rather than using fork+pipe+system+waitpid, most of which are only
available on POSIX-like systems, use popen which is also available on
Windows (under the name _popen).
Changes since v1:
- Create fread_noeintr to avoid EINTR in fread without reading any data.
- Handle short reads from fread. This can happen with non-conformant
libc or if EINTR occurs after reading some data.
- Define _POSIX_C_SOURCE for popen/pclose with strict implementations
which require it (e.g. gcc with -std=c11).
Changes since v2:
- Revert fread_noeintr and short read changes in v1 as unnecessary.
Signed-off-by: Kevin Locke <ke...@kevinlocke.name>
---
tools/configurator/configurator.c | 79 +++++++++++++++------------------------
1 file changed, 31 insertions(+), 48 deletions(-)
diff --git a/tools/configurator/configurator.c
b/tools/configurator/configurator.c
index c7577c0..2ad3fff 100644
--- a/tools/configurator/configurator.c
+++ b/tools/configurator/configurator.c
@@ -21,17 +21,19 @@
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
+#define _POSIX_C_SOURCE 200809L /* For pclose, popen, strdup */
+
#include <stdio.h>
#include <stdbool.h>
#include <stdlib.h>
-#include <unistd.h>
#include <err.h>
-#include <sys/types.h>
-#include <sys/wait.h>
-#include <sys/stat.h>
-#include <fcntl.h>
#include <string.h>
+#ifdef _MSC_VER
+#define popen _popen
+#define pclose _pclose
+#endif
+
#define DEFAULT_COMPILER "cc"
#define DEFAULT_FLAGS "-g3 -ggdb -Wall -Wundef -Wmissing-prototypes
-Wmissing-declarations -Wstrict-prototypes -Wold-style-definition"
@@ -375,20 +377,19 @@ static struct test tests[] = {
},
};
-static char *grab_fd(int fd)
+static char *grab_stream(FILE *file)
{
- int ret;
- size_t max, size = 0;
+ size_t max, ret, size = 0;
char *buffer;
- max = 16384;
- buffer = malloc(max+1);
- while ((ret = read(fd, buffer + size, max - size)) > 0) {
+ max = BUFSIZ;
+ buffer = malloc(max);
+ while ((ret = fread(buffer+size, 1, max - size, file)) == max - size) {
size += ret;
- if (size == max)
- buffer = realloc(buffer, max *= 2);
+ buffer = realloc(buffer, max *= 2);
}
- if (ret < 0)
+ size += ret;
+ if (ferror(file))
err(1, "reading from command");
buffer[size] = '\0';
return buffer;
@@ -396,43 +397,25 @@ static char *grab_fd(int fd)
static char *run(const char *cmd, int *exitstatus)
{
- pid_t pid;
- int p[2];
+ static const char redir[] = " 2>&1";
+ size_t cmdlen;
+ char *cmdredir;
+ FILE *cmdout;
char *ret;
- int status;
- if (pipe(p) != 0)
- err(1, "creating pipe");
-
- pid = fork();
- if (pid == -1)
- err(1, "forking");
-
- if (pid == 0) {
- if (dup2(p[1], STDOUT_FILENO) != STDOUT_FILENO
- || dup2(p[1], STDERR_FILENO) != STDERR_FILENO
- || close(p[0]) != 0
- || close(STDIN_FILENO) != 0
- || open("/dev/null", O_RDONLY) != STDIN_FILENO)
- exit(128);
-
- status = system(cmd);
- if (WIFEXITED(status))
- exit(WEXITSTATUS(status));
- /* Here's a hint... */
- exit(128 + WTERMSIG(status));
- }
+ cmdlen = strlen(cmd);
+ cmdredir = malloc(cmdlen + sizeof(redir));
+ memcpy(cmdredir, cmd, cmdlen);
+ memcpy(cmdredir + cmdlen, redir, sizeof(redir));
+
+ cmdout = popen(cmdredir, "r");
+ if (!cmdout)
+ err(1, "popen \"%s\"", cmdredir);
+
+ free(cmdredir);
- close(p[1]);
- ret = grab_fd(p[0]);
- /* This shouldn't fail... */
- if (waitpid(pid, &status, 0) != pid)
- err(1, "Failed to wait for child");
- close(p[0]);
- if (WIFEXITED(status))
- *exitstatus = WEXITSTATUS(status);
- else
- *exitstatus = -WTERMSIG(status);
+ ret = grab_stream(cmdout);
+ *exitstatus = pclose(cmdout);
return ret;
}
--
2.9.3
_______________________________________________
ccan mailing list
ccan@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/ccan
