From baf7eeb5d3483498700e49358b379c0c16886e26 Mon Sep 17 00:00:00 2001 From: Geoff Voelker Date: Wed, 3 Sep 1997 02:18:32 +0000 Subject: [PATCH] (get_env_size): New function. (spawn): Explicitly pass in environment when creating subprocess. (main): Cleaup error messages. Specify dynamically sized environment block for real shell. Pass on unhandled switches to real shell. Quote program name. (get_next_token): Null terminate token returned. --- nt/cmdproxy.c | 125 ++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 100 insertions(+), 25 deletions(-) diff --git a/nt/cmdproxy.c b/nt/cmdproxy.c index 4a270cfadce..18705af47f5 100644 --- a/nt/cmdproxy.c +++ b/nt/cmdproxy.c @@ -209,6 +209,7 @@ get_next_token (char * buf, char ** pSrc) char * p1 = skip_nonspace (p); memcpy (o, p, p1 - p); o += (p1 - p); + *o = '\0'; p = p1; } @@ -371,6 +372,7 @@ spawn (char * progname, char * cmdline) DWORD rc = 0xff; SECURITY_ATTRIBUTES sec_attrs; STARTUPINFO start; + char * envblock = GetEnvironmentStrings (); sec_attrs.nLength = sizeof (sec_attrs); sec_attrs.lpSecurityDescriptor = NULL; @@ -380,7 +382,7 @@ spawn (char * progname, char * cmdline) start.cb = sizeof (start); if (CreateProcess (progname, cmdline, &sec_attrs, NULL, TRUE, - 0, NULL, NULL, &start, &child)) + 0, envblock, NULL, &start, &child)) { /* wait for completion and pass on return code */ WaitForSingleObject (child.hProcess, INFINITE); @@ -390,9 +392,24 @@ spawn (char * progname, char * cmdline) child.hProcess = NULL; } + FreeEnvironmentStrings (envblock); + return (int) rc; } +/* Return size of current environment block. */ +int +get_env_size () +{ + char * start = GetEnvironmentStrings (); + char * tmp = start; + + while (tmp[0] || tmp[1]) + ++tmp; + FreeEnvironmentStrings (start); + return tmp + 2 - start; +} + /******* Main program ********************************************/ int @@ -403,6 +420,8 @@ main (int argc, char ** argv) char * cmdline; char * progname; int envsize; + char **pass_through_args; + int num_pass_through_args; char modname[MAX_PATH]; char path[MAX_PATH]; @@ -424,7 +443,7 @@ main (int argc, char ** argv) from the command line.) */ if (!GetModuleFileName (NULL, modname, sizeof (modname))) - fail ("GetModuleFileName failed"); + fail ("error: GetModuleFileName failed\n"); /* Although Emacs always sets argv[0] to an absolute pathname, we might get run in other ways as well, so convert argv[0] to an @@ -453,45 +472,72 @@ main (int argc, char ** argv) /* If no args, spawn real shell for interactive use. */ need_shell = TRUE; interactive = TRUE; - /* Ask for a reasonable size environment for command.com. */ - envsize = 1024; + /* Ask command.com to create an environment block with a reasonable + amount of free space. */ + envsize = get_env_size () + 300; + pass_through_args = (char **) alloca (argc * sizeof(char *)); + num_pass_through_args = 0; while (--argc > 0) { ++argv; - /* Only support single letter switches (except for -e); allow / as + /* Act on switches we recognize (mostly single letter switches, + except for -e); all unrecognised switches and extra args are + passed on to real shell if used (only really of benefit for + interactive use, but allow for batch use as well). Accept / as switch char for compatability with cmd.exe. */ - if ( ((*argv)[0] == '-' || (*argv)[0] == '/') - && (*argv)[1] != '\0' && (*argv)[2] == '\0' ) + if ( ((*argv)[0] == '-' || (*argv)[0] == '/') && (*argv)[1] != '\0' ) { if ( ((*argv)[1] == 'c') && ((*argv)[2] == '\0') ) { if (--argc == 0) - fail ("error: expecting arg for %s", *argv); + fail ("error: expecting arg for %s\n", *argv); cmdline = *(++argv); interactive = FALSE; } else if ( ((*argv)[1] == 'i') && ((*argv)[2] == '\0') ) { if (cmdline) - warn ("warning: %s ignored because of -c", *argv); + warn ("warning: %s ignored because of -c\n", *argv); } else if ( ((*argv)[1] == 'e') && ((*argv)[2] == ':') ) { - envsize = atoi (*argv + 3); - /* Enforce a reasonable minimum size. */ - if (envsize < 256) - envsize = 256; + int requested_envsize = atoi (*argv + 3); + /* Enforce a reasonable minimum size, as above. */ + if (requested_envsize > envsize) + envsize = requested_envsize; + /* For sanity, enforce a reasonable maximum. */ + if (envsize > 32768) + envsize = 32768; } else { - warn ("warning: unknown option %s ignored", *argv); + /* warn ("warning: unknown option %s ignored", *argv); */ + pass_through_args[num_pass_through_args++] = *argv; } } else break; } +#if 0 + /* I think this is probably not useful - cmd.exe ignores extra + (non-switch) args in interactive mode, and they cannot be passed on + when -c was given. */ + + /* Collect any remaining args after (initial) switches. */ + while (argc-- > 0) + { + pass_through_args[num_pass_through_args++] = *argv++; + } +#else + /* Probably a mistake for there to be extra args; not fatal. */ + if (argc > 0) + warn ("warning: extra args ignored after %s\n", argv[-1]); +#endif + + pass_through_args[num_pass_through_args] = NULL; + /* If -c option, determine if we must spawn a real shell, or if we can execute the command directly ourself. */ if (cmdline) @@ -525,26 +571,47 @@ main (int argc, char ** argv) if (need_shell) { char * p; + int extra_arg_space = 0; progname = getenv ("COMSPEC"); if (!progname) - fail ("error: COMSPEC is not set"); + fail ("error: COMSPEC is not set\n"); canon_filename (progname); progname = make_absolute (progname); if (progname == NULL || strchr (progname, '\\') == NULL) - fail ("make_absolute failed"); + fail ("error: the program %s could not be found.\n", getenv ("COMSPEC")); + + /* Work out how much extra space is required for + pass_through_args. */ + for (argv = pass_through_args; *argv != NULL; ++argv) + /* We don't expect to have to quote switches. */ + extra_arg_space += strlen (*argv) + 2; if (cmdline) { + char * buf; + /* Convert to syntax expected by cmd.exe/command.com for running non-interactively. Always quote program name in case path contains spaces (fortunately it can't contain quotes, since they are illegal in path names). */ - wsprintf (p = alloca (strlen (cmdline) + strlen (progname) + 7), - "\"%s\" /c %s", progname, cmdline); - cmdline = p; + + buf = p = alloca (strlen (progname) + extra_arg_space + + strlen (cmdline) + 16); + + /* Quote progname in case it contains spaces. */ + p += wsprintf (p, "\"%s\"", progname); + + /* Include pass_through_args verbatim; these are just switches + so should not need quoting. */ + for (argv = pass_through_args; *argv != NULL; ++argv) + p += wsprintf (p, " %s", *argv); + + /* Always set environment size to something reasonable. */ + wsprintf(p, " /e:%d /c %s", envsize, cmdline); + cmdline = buf; } else { @@ -556,15 +623,23 @@ main (int argc, char ** argv) - command.com doesn't like it), we always use the 8.3 form. */ GetShortPathName (progname, path, sizeof (path)); p = strrchr (path, '\\'); - /* Trailing slash is acceptable. */ - p++; + /* Trailing slash is acceptable, so always leave it. */ + *(++p) = '\0'; - /* Set environment size - again cmd.exe ignores this silently. */ - wsprintf (p, " /e:%d", envsize); + cmdline = p = alloca (strlen (progname) + extra_arg_space + + strlen (path) + 13); /* Quote progname in case it contains spaces. */ - wsprintf (cmdline = alloca (strlen (progname) + strlen (path) + 4), - "\"%s\" %s", progname, path); + p += wsprintf (p, "\"%s\" %s", progname, path); + + /* Include pass_through_args verbatim; these are just switches + so should not need quoting. */ + for (argv = pass_through_args; *argv != NULL; ++argv) + p += wsprintf (p, " %s", *argv); + + /* Always set environment size to something reasonable - again + cmd.exe ignores this silently. */ + wsprintf (p, " /e:%d", envsize); } } -- 2.39.2