projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 42d6e430 BJ |
1 | #include "stdio.h" |
| 2 | #include "signal.h" | |
| 3 | ||
| 4 | #define EASY 1 | |
| 5 | #define MEDIUM 2 | |
| 6 | #define HARD 3 | |
| 7 | ||
| 8 | mysys(s) | |
| 9 | char *s; | |
| 10 | { | |
| 11 | /* like "system" but rips off "mv", etc.*/ | |
| 12 | /* also tries to guess if can get away with exec cmd */ | |
| 13 | /* instead of sh cmd */ | |
| 14 | char p[300]; | |
| 15 | char *np[40]; | |
| 16 | register char *t; | |
| 17 | int nv, type, stat; | |
| 18 | ||
| 19 | type = EASY; /* we hope */ | |
| 20 | for (t = s; *t && type != HARD; t++) { | |
| 21 | switch (*t) { | |
| 22 | case '*': | |
| 23 | case '[': | |
| 24 | case '?': | |
| 25 | case '>': | |
| 26 | case '<': | |
| 27 | case '$': | |
| 28 | case '\'': | |
| 29 | case '"': | |
| 30 | type = MEDIUM; | |
| 31 | break; | |
| 32 | case '|': | |
| 33 | case ';': | |
| 34 | case '&': | |
| 35 | type = HARD; | |
| 36 | break; | |
| 37 | } | |
| 38 | } | |
| 39 | switch (type) { | |
| 40 | case HARD: | |
| 41 | return(system(s)); | |
| 42 | case MEDIUM: | |
| 43 | strcpy(p, "exec "); | |
| 44 | strcat(p, s); | |
| 45 | return(system(p)); | |
| 46 | case EASY: | |
| 47 | strcpy(p,s); | |
| 48 | nv = getargs(p, np); | |
| 49 | t=np[0]; | |
| 50 | if ((strcmp(t, "mv") == 0)|| | |
| 51 | (strcmp(t, "cp") == 0)|| | |
| 52 | (strcmp(t, "rm") == 0)|| | |
| 53 | (strcmp(t, "ls") == 0) ) { | |
| 54 | if (fork() == 0) { | |
| 55 | char b[100]; | |
| 56 | signal(SIGINT, SIG_DFL); | |
| 57 | strcpy(b, "/bin/"); | |
| 58 | strcat(b, t); | |
| 59 | np[nv] = 0; | |
| 60 | execv(b, np); | |
| 61 | fprintf(stderr, "Execv failed\n"); | |
| 62 | exit(1); | |
| 63 | } | |
| 64 | wait(&stat); | |
| 65 | return(stat); | |
| 66 | } | |
| 67 | return(system(s)); | |
| 68 | } | |
| 69 | } | |
| 70 | ||
| 71 | /* | |
| 72 | * system(): | |
| 73 | * same as library version, except that resets | |
| 74 | * default handling of signals in child, so that | |
| 75 | * user gets the behavior he expects. | |
| 76 | */ | |
| 77 | ||
| 78 | system(s) | |
| 79 | char *s; | |
| 80 | { | |
| 81 | int status, pid, w; | |
| 82 | register int (*istat)(), (*qstat)(); | |
| 83 | ||
| 84 | istat = signal(SIGINT, SIG_IGN); | |
| 85 | qstat = signal(SIGQUIT, SIG_IGN); | |
| 86 | if ((pid = fork()) == 0) { | |
| 87 | signal(SIGINT, SIG_DFL); | |
| 88 | signal(SIGQUIT, SIG_DFL); | |
| 89 | execl("/bin/sh", "sh", "-c", s, 0); | |
| 90 | _exit(127); | |
| 91 | } | |
| 92 | while ((w = wait(&status)) != pid && w != -1) | |
| 93 | ; | |
| 94 | if (w == -1) | |
| 95 | status = -1; | |
| 96 | signal(SIGINT, istat); | |
| 97 | signal(SIGQUIT, qstat); | |
| 98 | return(status); | |
| 99 | } | |
| 100 | ||
| 101 | getargs(s, v) | |
| 102 | char *s, **v; | |
| 103 | { | |
| 104 | int i; | |
| 105 | ||
| 106 | i = 0; | |
| 107 | for (;;) { | |
| 108 | v[i++]=s; | |
| 109 | while (*s != 0 && *s!=' '&& *s != '\t') | |
| 110 | s++; | |
| 111 | if (*s == 0) | |
| 112 | break; | |
| 113 | *s++ =0; | |
| 114 | while (*s == ' ' || *s == '\t') | |
| 115 | s++; | |
| 116 | if (*s == 0) | |
| 117 | break; | |
| 118 | } | |
| 119 | return(i); | |
| 120 | } |