add mkdir_maybe

[libjh.git] / io.c

diff --git a/io.c b/io.c
index 3c0a8eb..ef1f912 100644 (file)
--- a/io.c
+++ b/io.c
@@ -1,11 +1,10 @@
 // Copyright (2013) Jann Horn <jann@thejh.net>
-// This code is licensed under the AGPLv3.
 
 HEADER #include <sys/types.h>
 #include <unistd.h>
 #include <errno.h>
 #include <stdlib.h>
-#include <stdbool.h>
+HEADER #include <stdbool.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <string.h>
@@ -24,6 +23,7 @@ PUBLIC_FN ssize_t read_nointr(int fd, void *buf, size_t count, int *last_res) {
   size_t done = 0;
   while (done < count) {
     ssize_t part_res = read(fd, buf+done, count-done);
+    if (part_res == -1 && errno == EINTR) continue;
     if (part_res <= 0) {
       if (last_res) *last_res = part_res;
       if (done) return done;
@@ -42,11 +42,13 @@ PUBLIC_FN ssize_t read_nointr(int fd, void *buf, size_t count, int *last_res) {
 //  - -1: error
 //  - 0: stream ended
 //  - 1: no problems occured
-PUBLIC_FN ssize_t write_nointr(int fd, void *buf, size_t count, int *last_res) {
+PUBLIC_FN ssize_t write_nointr(int fd, void *buf, ssize_t count, int *last_res) {
+  if (count == -1) count = strlen(buf);
   errno = 0;
   size_t done = 0;
   while (done < count) {
     ssize_t part_res = write(fd, buf+done, count-done);
+    if (part_res == -1 && errno == EINTR) continue;
     if (part_res <= 0) {
       if (last_res) *last_res = part_res;
       if (done) return done;
@@ -179,3 +181,37 @@ PUBLIC_FN void *mmap_file(void *addr, size_t length, int prot, int flags, char *
   errno = errno_;
   return (r==MAP_FAILED) ? NULL : r;
 }
+
+// on error, fd remains unchanged, no matter whether you specified "keep" or not
+HEADER #define JH_OBS_KEEPFD 1
+HEADER #define JH_OBS_BUFFER 2
+PUBLIC_FN int fopen_bistream(FILE **in, FILE **out, int fd, int flags) {
+  // check input
+  if (fd < 0) goto err_out;
+  bool keep = flags & JH_OBS_KEEPFD;
+  bool buffer = flags & JH_OBS_BUFFER;
+
+  // create input FILE*
+  int in_fd = dup(fd);
+  if (in_fd < 0) goto err_out;
+  *in = fdopen(in_fd, "r");
+  if (!*in) { close(in_fd); goto err_out; }
+
+  // create output FILE*
+  int out_fd = keep ? dup(fd) : fd;
+  if (out_fd < 0) goto err_dup_out;
+  *out = fdopen(out_fd, "w");
+  if (!*out) { if (keep) close(out_fd); goto err_dup_out; }
+
+  // avoid buffering data unless the caller really wants it
+  if (!buffer) setbuf(*out, NULL);
+
+  // success!
+  return 0;
+
+
+err_dup_out:
+  fclose(*in);
+err_out:
+  return EAI_SYSTEM;
+}
\ No newline at end of file