Alistair Delva | beaee83 | 2021-02-24 11:27:23 -0800 | [diff] [blame] | 1 | /* Copyright 1986-1992 Emmet P. Gray. |
| 2 | * Copyright 1996-2002,2007,2009 Alain Knaff. |
| 3 | * This file is part of mtools. |
| 4 | * |
| 5 | * Mtools is free software: you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation, either version 3 of the License, or |
| 8 | * (at your option) any later version. |
| 9 | * |
| 10 | * Mtools is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with Mtools. If not, see <http://www.gnu.org/licenses/>. |
| 17 | * |
| 18 | * Do filename expansion with the shell. |
| 19 | */ |
| 20 | |
| 21 | #include "sysincludes.h" |
| 22 | #include "mtools.h" |
| 23 | |
| 24 | #ifndef OS_mingw32msvc |
| 25 | ssize_t safePopenOut(const char **command, char *output, size_t len) |
| 26 | { |
| 27 | int pipefd[2]; |
| 28 | pid_t pid; |
| 29 | int status; |
| 30 | ssize_t last; |
| 31 | |
| 32 | if(pipe(pipefd)) { |
| 33 | return -2; |
| 34 | } |
| 35 | switch((pid=fork())){ |
| 36 | case -1: |
| 37 | return -2; |
| 38 | case 0: /* the son */ |
| 39 | close(pipefd[0]); |
| 40 | destroy_privs(); |
| 41 | close(1); |
| 42 | close(2); /* avoid nasty error messages on stderr */ |
| 43 | if(dup(pipefd[1]) < 0) { |
| 44 | perror("Dup error"); |
| 45 | exit(1); |
| 46 | } |
| 47 | close(pipefd[1]); |
| 48 | execvp(command[0], (char**)(command+1)); |
| 49 | exit(1); |
| 50 | default: |
| 51 | close(pipefd[1]); |
| 52 | break; |
| 53 | } |
| 54 | last=read(pipefd[0], output, len); |
| 55 | kill(pid,9); |
| 56 | wait(&status); |
| 57 | if(last<0) { |
| 58 | return -1; |
| 59 | } |
| 60 | return last; |
| 61 | } |
| 62 | #endif |
| 63 | |
| 64 | |
| 65 | const char *expand(const char *input, char *ans) |
| 66 | { |
| 67 | #ifndef OS_mingw32msvc |
| 68 | ssize_t last; |
| 69 | char buf[256]; |
| 70 | const char *command[] = { "/bin/sh", "sh", "-c", 0, 0 }; |
| 71 | |
| 72 | ans[EXPAND_BUF-1]='\0'; |
| 73 | |
| 74 | if (input == NULL) |
| 75 | return(NULL); |
| 76 | if (*input == '\0') |
| 77 | return(""); |
| 78 | /* any thing to expand? */ |
| 79 | if (!strpbrk(input, "$*(){}[]\\?`~")) { |
| 80 | strncpy(ans, input, EXPAND_BUF-1); |
| 81 | return(ans); |
| 82 | } |
| 83 | /* popen an echo */ |
| 84 | #ifdef HAVE_SNPRINTF |
| 85 | snprintf(buf, 255, "echo %s", input); |
| 86 | #else |
| 87 | sprintf(buf, "echo %s", input); |
| 88 | #endif |
| 89 | |
| 90 | command[3]=buf; |
| 91 | last=safePopenOut(command, ans, EXPAND_BUF-1); |
| 92 | if(last<0) { |
| 93 | perror("Pipe read error"); |
| 94 | exit(1); |
| 95 | } |
| 96 | if(last) |
| 97 | ans[last-1] = '\0'; |
| 98 | else |
| 99 | strncpy(ans, input, EXPAND_BUF-1); |
| 100 | return ans; |
| 101 | #else |
| 102 | strncpy(ans, input, EXPAND_BUF-1); |
| 103 | ans[EXPAND_BUF-1]='\0'; |
| 104 | return ans; |
| 105 | #endif |
| 106 | } |