projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 455d17bb JL |
1 | static char Sccsid[] = "@(#)fatal.c 1.2 %G%"; |
| 2 | ||
| 82bd445e JL |
3 | # include "../hdr/macros.h" |
| 4 | # include "../hdr/fatal.h" | |
| 82bd445e JL |
5 | |
| 6 | /* | |
| 7 | General purpose error handler. | |
| 8 | Typically, low level subroutines which detect error conditions | |
| 9 | (an open or create routine, for example) return the | |
| 10 | value of calling fatal with an appropriate error message string. | |
| 11 | E.g., return(fatal("can't do it")); | |
| 12 | Higher level routines control the execution of fatal | |
| 13 | via the global word Fflags. | |
| 14 | The macros FSAVE and FRSTR in <fatal.h> can be used by higher | |
| 15 | level subroutines to save and restore the Fflags word. | |
| 16 | ||
| 17 | The argument to fatal is a pointer to an error message string. | |
| 18 | The action of this routine is driven completely from | |
| 19 | the "Fflags" global word (see <fatal.h>). | |
| 20 | The following discusses the interpretation of the various bits | |
| 21 | of Fflags. | |
| 22 | ||
| 23 | The FTLMSG bit controls the writing of the error | |
| 24 | message on file descriptor 2. The message is preceded | |
| 25 | by the string "ERROR: ", unless the global character pointer | |
| 26 | "Ffile" is non-zero, in which case the message is preceded | |
| 27 | by the string "ERROR [<Ffile>]: ". A newline is written | |
| 28 | after the user supplied message. | |
| 29 | ||
| 30 | If the FTLCLN bit is on, clean_up is called with an | |
| 31 | argument of 0 (see clean.c). | |
| 32 | ||
| 33 | If the FTLFUNC bit is on, the function pointed to by the global | |
| 34 | function pointer "Ffunc" is called with the user supplied | |
| 35 | error message pointer as argument. | |
| 36 | (This feature can be used to log error messages). | |
| 37 | ||
| 38 | The FTLACT bits determine how fatal should return. | |
| 39 | If the FTLJMP bit is on longjmp(Fjmp) is | |
| 40 | called (Fjmp is a global vector of 10 words, see | |
| 41 | setjmp, longjmp documentation). | |
| 42 | ||
| 43 | If the FTLEXIT bit is on the value of userexit(1) is | |
| 44 | passed as an argument to exit(II) | |
| 45 | (see userexit.c). | |
| 46 | ||
| 47 | If none of the FTLACT bits are on | |
| 48 | (the default value for Fflags is 0), the global word | |
| 49 | "Fvalue" (initialized to -1) is returned. | |
| 50 | ||
| 51 | If all fatal globals have their default values, fatal simply | |
| 52 | returns -1. | |
| 53 | */ | |
| 54 | ||
| 55 | int Fcnt; | |
| 56 | int Fflags; | |
| 57 | char *Ffile; | |
| 455d17bb | 58 | int Fvalue = -1; |
| 82bd445e JL |
59 | int (*Ffunc)(); |
| 60 | int Fjmp[10]; | |
| 61 | ||
| 62 | ||
| 63 | fatal(msg) | |
| 64 | char *msg; | |
| 65 | { | |
| 66 | ++Fcnt; | |
| 67 | if (Fflags & FTLMSG) { | |
| 68 | syswrite(2,"ERROR",5); | |
| 69 | if (Ffile) { | |
| 70 | syswrite(2," [",2); | |
| 71 | syswrite(2,Ffile,length(Ffile)); | |
| 72 | syswrite(2,"]",1); | |
| 73 | } | |
| 74 | syswrite(2,": ",2); | |
| 75 | syswrite(2,msg,length(msg)); | |
| 76 | syswrite(2,"\n",1); | |
| 77 | } | |
| 78 | if (Fflags & FTLCLN) | |
| 79 | clean_up(0); | |
| 80 | if (Fflags & FTLFUNC) | |
| 81 | (*Ffunc)(msg); | |
| 82 | switch (Fflags & FTLACT) { | |
| 83 | case FTLJMP: | |
| 84 | longjmp(Fjmp, 1); | |
| 85 | case FTLEXIT: | |
| 86 | exit(userexit(1)); | |
| 87 | case FTLRET: | |
| 88 | return(Fvalue); | |
| 89 | } | |
| 90 | } |