Initial checkin of Leslie Barstow's 1993 v1.0 write(1) implementation,

minus the man page.

usr.bin/write/write.c

@@ -0,0 +1,131 @@
+/* write.cc  - UNIX-like write utility.  Send message to terminal. */
+/* Copyright 1993 by Leslie M. Barstow III */
+/* Placed in the Public Domain with the following condition:
+      Please retain original Copyright in source, program, and manpage. */
+
+#pragma optimize -1
+#pragma debug 0
+#pragma stacksize 1024
+
+#define O_WRONLY  0x0002
+
+#include <time.h>
+#include <types.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <orca.h>
+#include <utmp.h>
+#include <fcntl.h>
+
+void Usage(void)
+{fputs("usage: write username [message]\n",stdout);
+ fputs("GS write: Copyright 1993 by Leslie M. Barstow III.\n", stdout);
+}
+
+int userTTY(char *user, int **list)
+{int fd, tmp;
+ struct utmp uentry;
+ int count = 0;
+ int *newlist;
+ fd=open(_PATH_UTMP, 257);
+ if (fd < 1)
+  {fputs("write - unable to retrieve current users.\n", stdout);
+   exit(-1);
+  }
+ do
+   {tmp = read(fd, (void *)(&uentry), sizeof(uentry));
+    if (tmp)
+      {if (!strncmp(uentry.ut_name,user,strlen(user)))
+	       {count++;
+          newlist = (int *)realloc(*list, count *2);
+          if (newlist == (int *)0L)
+	          {for (tmp = 1; tmp < count; tmp++)
+	             close((*list)[tmp-1]);
+             free(*list);
+             close(fd);
+             fputs("write - unable to allocate memory.\n", stdout);
+             exit(-1);
+            }
+          *list = newlist;
+          (*list)[count-1] = open(uentry.ut_line, 0x0002);
+          if ((*list)[count-1]  < 1)
+	          {fputs("write - unable to open terminal ",stdout);
+             fputs(uentry.ut_line, stdout);
+             fputs(".\n", stdout);
+             count--;
+            }
+         }
+      }
+   }
+ while (tmp);
+ close(fd);
+ return(count);
+}
+
+
+int main(int argc, char **argv)
+{int count;
+ int i;
+ int j = 2;
+ char *line, *uname;
+ int *fdlist = (int *)0L;
+
+if (argc > 3)
+  {Usage();
+   exit(-1);
+  }
+if (argc == 3)
+  {count = userTTY(argv[1], &fdlist);
+   if (count < 1)
+     {fputs("write - no active terminals for user.\n", stdout);
+      exit(-1);
+     }
+
+   uname = getenv("user");
+   for (i = 0; i < count; i++)
+     {write(fdlist[i], "\n\aMessage from ", 15);
+      write(fdlist[i], uname, strlen(uname));
+      write(fdlist[i], ".\r\n", 3);
+      write(fdlist[i], argv[2], strlen(argv[2]));
+      write(fdlist[i], "\r\n", 2);
+     }
+   for (i = 0; i < count; i++)
+      close(fdlist[i]);
+   exit(0);
+  }
+if ((argc == 2) && (argv[1][0] != '-'))  /* enter read loop */
+  {line = (char *)malloc(256);
+   if (line == (char *)0L)
+     {fputs("write - error allocating buffer.\n", stdout);
+      exit(-1);
+     }
+   count = userTTY(argv[1], &fdlist);
+   if (count < 1)
+  	{fputs("write - no active terminals for user.\n", stdout);
+      free(line);
+      exit(-1);
+  	}
+   uname = getenv("user");
+   for(i = 0; i < count; i++)
+     {write(fdlist[i], "\n\aMessage from ", 15);
+      write(fdlist[i], uname, strlen(uname));
+      write(fdlist[i], ".\r\n", 3);
+     }
+   while (j > 1)
+     {fgets(line, 256, stdin);
+      j = strlen(line);
+      for (i = 0; i< count; i++)
+  	    write(fdlist[i], line, j);
+         
+  	}
+   free(line);
+   for (i = 0; i < count; i++)
+      close(fdlist[i]);
+   exit(0);
+  }
+else
+  {Usage();
+   exit(-1);
+  }
+}