Edit File: query.c
/*- * See the file LICENSE for redistribution information. * * Copyright (c) 2005,2008 Oracle. All rights reserved. * * $Id: query.c,v 1.17 2008/01/08 20:58:23 bostic Exp $ */ #include "csv.h" #include "csv_local.h" #include "csv_extern.h" static int query_by_field(char *); static int query_fieldlist(char *); static int query_help(char *); static int query_usage(void); typedef struct _cmdtab { char *cmd; /* Command name */ int (*f)(char *); /* Underlying function. */ char *help; /* Help message. */ } CMDTAB; static CMDTAB cmdtab[] = { { "?", query_help, "?\t\tDisplay help screen" }, { "exit", NULL, "exit\t\tExit program" }, { "fields", query_fieldlist, "fields\t\tDisplay list of field names" }, { "help", query_help, "help\t\tDisplay help screen" }, { "quit", NULL, "quit\t\tExit program" }, { NULL, query_by_field, "field[op]value\tDisplay fields by value (=, !=, <, <=, >, >=, ~, !~)" }, { NULL, NULL, NULL } }; /* * query_interactive -- * Allow the user to interactively query the database. */ int query_interactive() { int done; char *p, input[256]; for (;;) { printf("Query: "); (void)fflush(stdout); if (fgets(input, sizeof(input), stdin) == NULL) { printf("\n"); if (ferror(stdin)) { dbenv->err(dbenv, errno, "error occurred reading from stdin"); return (1); } break; } if ((p = strchr(input, '\n')) == NULL) { dbenv->errx(dbenv, "input buffer too small"); return (1); } *p = '\0'; if (query(input, &done) != 0) return (1); if (done != 0) break; } return (0); } /* * query -- * Process a query. */ int query(char *cmd, int *donep) { CMDTAB *p; if (donep != NULL) *donep = 0; for (p = cmdtab; p->cmd != NULL; ++p) if (p->cmd != NULL && strncasecmp(cmd, p->cmd, strlen(p->cmd)) == 0) break; if (p->cmd == NULL) return (query_by_field(cmd)); if (p->f == NULL) { if (donep != NULL) *donep = 1; return (0); } return (p->f(cmd)); } /* * query_by_field -- * Query the primary database by field. */ static int query_by_field(char *input) { OPERATOR operator; size_t len; char *field, *op, *value; /* * We expect to see "field [op] value" -- figure it out. * * Skip leading whitespace. */ while (isspace(*input)) ++input; /* * Find an operator, and it better not start the string. */ if ((len = strcspn(field = input, "<>!=~")) == 0) return (query_usage()); op = field + len; /* Figure out the operator, and find the start of the value. */ switch (op[0]) { case '~': operator = WC; value = op + 1; break; case '!': if (op[1] == '=') { operator = NEQ; value = op + 2; break; } if (op[1] == '~') { operator = NWC; value = op + 2; break; } return (query_usage()); case '<': if (op[1] == '=') { operator = LTEQ; value = op + 2; } else { operator = LT; value = op + 1; } break; case '=': operator = EQ; if (op[1] == '=') value = op + 2; else value = op + 1; break; case '>': if (op[1] == '=') { operator = GTEQ; value = op + 2; } else { operator = GT; value = op + 1; } break; default: return (query_usage()); } /* Terminate the field name, and there better be a field name. */ while (--op > input && isspace(*op)) ; if (op == input) return (query_usage()); op[1] = '\0'; /* Make sure there is a value field. */ while (isspace(*value)) ++value; if (*value == '\0') return (query_usage()); return (DbRecord_search_field_name(field, value, operator)); } /* * query_fieldlist -- * Display list of field names. */ static int query_fieldlist(char *input) { DbField *f; input = input; /* Quiet compiler. */ for (f = fieldlist; f->name != NULL; ++f) printf("field %3d: %s\n", f->fieldno, f->name); return (0); } /* * query_help -- * Query command list. */ static int query_help(char *input) { CMDTAB *p; input = input; /* Quiet compiler. */ printf("Query commands:\n"); for (p = cmdtab; p->help != NULL; ++p) printf("\t%s\n", p->help); return (0); } /* * query_usage -- * Query usage message. */ static int query_usage(void) { fprintf(stderr, "%s: query syntax error\n", progname); return (query_help(NULL)); }
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