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Diffstat (limited to 'libmisc/loginprompt.c')
| -rw-r--r-- | libmisc/loginprompt.c | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/libmisc/loginprompt.c b/libmisc/loginprompt.c new file mode 100644 index 0000000..b008e2a --- /dev/null +++ b/libmisc/loginprompt.c @@ -0,0 +1,178 @@ +/* + * Copyright (c) 1989 - 1993, Julianne Frances Haugh + * Copyright (c) 1996 - 2000, Marek Michałkiewicz + * Copyright (c) 2003 - 2005, Tomasz Kłoczko + * Copyright (c) 2008 - 2011, Nicolas François + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The name of the copyright holders or contributors may not be used to + * endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A + * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include <config.h> + +#ident "$Id$" + +#include <assert.h> +#include <stdio.h> +#include <signal.h> +#include <ctype.h> +#include "prototypes.h" +#include "defines.h" +#include "getdef.h" + +static void login_exit (unused int sig) +{ + exit (EXIT_FAILURE); +} + +/* + * login_prompt - prompt the user for their login name + * + * login_prompt() displays the standard login prompt. If ISSUE_FILE + * is set in login.defs, this file is displayed before the prompt. + */ + +void login_prompt (const char *prompt, char *name, int namesize) +{ + char buf[1024]; + +#define MAX_ENV 32 + char *envp[MAX_ENV]; + char *cp; + int i; + FILE *fp; + + RETSIGTYPE (*sigquit) (int); +#ifdef SIGTSTP + RETSIGTYPE (*sigtstp) (int); +#endif + + /* + * There is a small chance that a QUIT character will be part of + * some random noise during a prompt. Deal with this by exiting + * instead of core dumping. If SIGTSTP is defined, do the same + * thing for that signal. + */ + + sigquit = signal (SIGQUIT, login_exit); +#ifdef SIGTSTP + sigtstp = signal (SIGTSTP, login_exit); +#endif + + /* + * See if the user has configured the issue file to + * be displayed and display it before the prompt. + */ + + if (NULL != prompt) { + const char *fname = getdef_str ("ISSUE_FILE"); + if (NULL != fname) { + fp = fopen (fname, "r"); + if (NULL != fp) { + while ((i = getc (fp)) != EOF) { + (void) putc (i, stdout); + } + + (void) fclose (fp); + } + } + (void) gethostname (buf, sizeof buf); + printf (prompt, buf); + (void) fflush (stdout); + } + + /* + * Read the user's response. The trailing newline will be + * removed. + */ + + memzero (buf, sizeof buf); + if (fgets (buf, (int) sizeof buf, stdin) != buf) { + exit (EXIT_FAILURE); + } + + cp = strchr (buf, '\n'); + if (NULL == cp) { + exit (EXIT_FAILURE); + } + *cp = '\0'; /* remove \n [ must be there ] */ + + /* + * Skip leading whitespace. This makes " username" work right. + * Then copy the rest (up to the end or the first "non-graphic" + * character into the username. + */ + + for (cp = buf; *cp == ' ' || *cp == '\t'; cp++); + + for (i = 0; i < namesize - 1 && isgraph (*cp); name[i++] = *cp++); + while (isgraph (*cp)) { + cp++; + } + + if ('\0' != *cp) { + cp++; + } + + name[i] = '\0'; + + /* + * This is a disaster, at best. The user may have entered extra + * environmental variables at the prompt. There are several ways + * to do this, and I just take the easy way out. + */ + + if ('\0' != *cp) { /* process new variables */ + char *nvar; + int count = 1; + int envc; + + for (envc = 0; envc < MAX_ENV; envc++) { + nvar = strtok ((0 != envc) ? (char *) 0 : cp, " \t,"); + if (NULL == nvar) { + break; + } + if (strchr (nvar, '=') != NULL) { + envp[envc] = nvar; + } else { + size_t len = strlen (nvar) + 32; + envp[envc] = xmalloc (len); + (void) snprintf (envp[envc], len, + "L%d=%s", count++, nvar); + } + } + set_env (envc, envp); + } + + /* + * Set the SIGQUIT handler back to its original value + */ + + (void) signal (SIGQUIT, sigquit); +#ifdef SIGTSTP + (void) signal (SIGTSTP, sigtstp); +#endif +} + |