print visible representations of non printable characters

SCCS-vsn: usr.bin/write/write.c 4.9

diff --git a/usr/src/usr.bin/write/write.c b/usr/src/usr.bin/write/write.c
index a5bbf25..87ee682 100644 (file)
--- a/usr/src/usr.bin/write/write.c
+++ b/usr/src/usr.bin/write/write.c
@@ -1,9 +1,12 @@
-static char *sccsid = "@(#)write.c     4.8 %G%";
+#ifndef        lint
+static char *sccsid = "@(#)write.c     4.9 %G%";
+#endif

 /*
  * write to another user
  */
 
 #include <stdio.h>
 /*
  * write to another user
  */
 
 #include <stdio.h>

+#include <ctype.h>

 #include <sys/types.h>
 #include <sys/stat.h>
 #include <signal.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <signal.h>


@@ -17,7 +20,7 @@ char  *strcat();
 char   *strcpy();
 struct utmp ubuf;
 int    signum[] = {SIGHUP, SIGINT, SIGQUIT, 0};
 char   *strcpy();
 struct utmp ubuf;
 int    signum[] = {SIGHUP, SIGINT, SIGQUIT, 0};

-char   me[10]  = "???";
+char   me[NMAX + 1]    = "???";

 char   *him;
 char   *mytty;
 char   histty[32];
 char   *him;
 char   *mytty;
 char   histty[32];


@@ -43,27 +46,28 @@ main(argc, argv)
        struct tm *localclock = localtime( &clock );
 
        if (argc < 2) {
        struct tm *localclock = localtime( &clock );
 
        if (argc < 2) {

-               printf("usage: write user [ttyname]\n");
+               fprintf(stderr, "Usage: write user [ttyname]\n");

                exit(1);
        }
        him = argv[1];
        if (argc > 2)
                histtya = argv[2];
        if ((uf = fopen("/etc/utmp", "r")) == NULL) {
                exit(1);
        }
        him = argv[1];
        if (argc > 2)
                histtya = argv[2];
        if ((uf = fopen("/etc/utmp", "r")) == NULL) {

-               printf("cannot open /etc/utmp\n");
+               perror("write: Can't open /etc/utmp");

                goto cont;
        }
        mytty = ttyname(2);
        if (mytty == NULL) {
                goto cont;
        }
        mytty = ttyname(2);
        if (mytty == NULL) {

-               printf("Can't find your tty\n");
+               fprintf(stderr, "write: Can't find your tty\n");

                exit(1);
        }
        if (stat(mytty, &stbuf) < 0) {
                exit(1);
        }
        if (stat(mytty, &stbuf) < 0) {

-               printf("Can't stat your tty\n");
+               perror("write: Can't stat your tty");

                exit(1);
        }
        if ((stbuf.st_mode&02) == 0) {
                exit(1);
        }
        if ((stbuf.st_mode&02) == 0) {

-               printf("You have write permission turned off.\n");
+               fprintf(stderr,
+                       "write: You have write permission turned off\n");

                exit(1);
        }
        mytty = rindex(mytty, '/') + 1;
                exit(1);
        }
        mytty = rindex(mytty, '/') + 1;


@@ -84,7 +88,8 @@ main(argc, argv)
                                        break;
                        }
                }
                                        break;
                        }
                }

-               if (him[0] != '-' || him[1] != 0)
+               if (him[0] == '-' && him[1] == 0)
+                       goto nomat;

                for (i=0; i<NMAX; i++) {
                        c1 = him[i];
                        c2 = ubuf.ut_name[i];
                for (i=0; i<NMAX; i++) {
                        c1 = him[i];
                        c2 = ubuf.ut_name[i];


@@ -104,12 +109,15 @@ main(argc, argv)
        }
 cont:
        if (logcnt==0 && histty[0]=='\0') {
        }
 cont:
        if (logcnt==0 && histty[0]=='\0') {

-               printf("%s not logged in.\n", him);
+               fprintf(stderr, "write: %s not logged in\n", him);

                exit(1);
        }
                exit(1);
        }

-       fclose(uf);
+       if (uf != NULL)
+               fclose(uf);

        if (histtya==0 && logcnt > 1) {
        if (histtya==0 && logcnt > 1) {

-               printf("%s logged more than once\nwriting to %s\n", him, histty+5);
+               fprintf(stderr,
+               "write: %s logged in more than once ... writing to %s\n",
+                       him, histty+5);

        }
        if (histty[0] == 0) {
                printf(him);
        }
        if (histty[0] == 0) {
                printf(him);


@@ -119,7 +127,7 @@ cont:
                exit(1);
        }
        if (access(histty, 0) < 0) {
                exit(1);
        }
        if (access(histty, 0) < 0) {

-               printf("No such tty\n");
+               fprintf(stderr, "write: No such tty\n");

                exit(1);
        }
        signal(SIGALRM, timout);
                exit(1);
        }
        signal(SIGALRM, timout);


@@ -134,14 +142,15 @@ cont:
        sigs(eof);
        { char hostname[32];
          gethostname(hostname, sizeof (hostname));
        sigs(eof);
        { char hostname[32];
          gethostname(hostname, sizeof (hostname));

-         fprintf(tf, "\r\nMessage from ");
-         fprintf(tf, "%s!%s on %s at %d:%02d ...\r\n\007\007\007",
-             hostname, me, mytty, localclock->tm_hour, localclock->tm_min);
-       }
+         fprintf(tf,
+             "\r\nMessage from %s@%s on %s at %d:%02d ...\r\n\007\007\007",
+             me, hostname, mytty, localclock->tm_hour, localclock->tm_min);

        fflush(tf);
        fflush(tf);

+       }

        for (;;) {
        for (;;) {

-               char buf[128];
-               i = read(0, buf, 128);
+               char buf[BUFSIZ];
+               register char *bp;
+               i = read(0, buf, sizeof buf);

                if (i <= 0)
                        eof();
                if (buf[0] == '!') {
                if (i <= 0)
                        eof();
                if (buf[0] == '!') {


@@ -149,22 +158,43 @@ cont:
                        ex(buf);
                        continue;
                }
                        ex(buf);
                        continue;
                }

-               if (write(fileno(tf), buf, i) != i) {
-                       printf("\n\007Write failed (%s logged out?)\n", him);
-                       exit(1);
+               for (bp = buf; --i >= 0; bp++) {
+                       if (*bp == '\n')
+                               putc('\r', tf);
+
+                       if (!isascii(*bp)) {
+                               putc('M', tf);
+                               putc('-', tf);
+                               *bp = toascii(*bp);
+                       }
+
+                       if (isprint(*bp) ||
+                           *bp == ' ' || *bp == '\t' || *bp == '\n') {
+                               putc(*bp, tf);
+                       } else {
+                               putc('^', tf);
+                               putc(*bp ^ 0100, tf);
+                       }
+
+                       if (*bp == '\n')
+                               fflush(tf);
+
+                       if (ferror(tf) || feof(tf)) {
+                               printf("\n\007Write failed (%s logged out?)\n",
+                                       him);
+                               exit(1);
+                       }

                }
                }

-               if (buf[i-1] == '\n')
-                       write(fileno(tf), "\r", 1);

        }
 perm:
        }
 perm:

-       printf("Permission denied\n");
+       fprintf(stderr, "write: Permission denied\n");

        exit(1);
 }
 
 timout()
 {
 
        exit(1);
 }
 
 timout()
 {
 

-       printf("Timeout opening their tty\n");
+       fprintf(stderr, "write: Timeout opening their tty\n");

        exit(1);
 }
 
        exit(1);
 }