X-Git-Url: http://git.thejh.net/?p=libjh.git;a=blobdiff_plain;f=io.c;h=1ef3d3df9361126266e73b0fe45d0934457d2e4f;hp=d2b3197027b69cd4fc0e40f1333a123887a38a7f;hb=0fa47e6453747e3ef4ab707a5bcb34980a465a75;hpb=95317cdba6d5b393db2e68f44487456ea0d99664

diff --git a/io.c b/io.c
index d2b3197..1ef3d3d 100644
--- a/io.c
+++ b/io.c
@@ -1,15 +1,13 @@
 // 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>
-#include <assert.h>
 #include <sys/mman.h>
 
 // Wrapper for `read` that retries on partial reads.
@@ -24,6 +22,7 @@ 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 +41,13 @@ 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;
@@ -67,6 +68,9 @@ PUBLIC_FN ssize_t write_nointr(int fd, void *buf, size_t count, int *last_res) {
 PUBLIC_CONST JH_SLURP_NO_STAT 1
 PUBLIC_CONST JH_SLURP_REALLOC 2 /* realloc result block if it saves RAM */
 PUBLIC_CONST JH_SLURP_8BYTE_PAD 4 /* pad buffer with eight nullbytes, not one */
+PUBLIC_CONST JH_SLURP_FIXSIZE 8 /* len_out is actually input and specifies
+HEADER                             the expected length. if there is more data,
+HEADER                             that might be ignored silently. */
 PUBLIC_FN void *slurp_fd(int fd, size_t *len_out, int flags) {
   int errno_;
   
@@ -75,6 +79,13 @@ PUBLIC_FN void *slurp_fd(int fd, size_t *len_out, int flags) {
   size_t size_guess = 1023;
   bool trusted_guess = false; /* can we rely on the guess? */
   
+  if (flags&JH_SLURP_FIXSIZE) {
+    size_guess = *len_out;
+    trusted_guess = true;
+    // if we want a fixed size, of course we don't want to stat
+    flags |= JH_SLURP_NO_STAT;
+  }
+  
   int padlen = (flags&JH_SLURP_8BYTE_PAD)?8:1;
   
   // If we can determine the exact size, we don't have to guess. So try
@@ -113,6 +124,12 @@ PUBLIC_FN void *slurp_fd(int fd, size_t *len_out, int flags) {
         char *buf_ = realloc(buf, done+padlen);
         if (buf_) buf = buf_;
       }
+      if (done != size_guess && (flags&JH_SLURP_FIXSIZE)) {
+        free(buf);
+        // not the most correct error message ever, but whatever.
+        errno = EFBIG;
+        return NULL;
+      }
       if (len_out) *len_out = done;
       return buf;
     }
@@ -163,3 +180,37 @@ 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;
+}