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-rw-r--r--pcregrep.c228
1 files changed, 228 insertions, 0 deletions
diff --git a/pcregrep.c b/pcregrep.c
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+/*************************************************
+* pcregrep program *
+*************************************************/
+
+/* This is a grep program that uses the PCRE regular expression library to do
+its pattern matching. */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include "config.h"
+#include "pcre.h"
+
+#define FALSE 0
+#define TRUE 1
+
+typedef int BOOL;
+
+
+
+/*************************************************
+* Global variables *
+*************************************************/
+
+static pcre *pattern;
+static pcre_extra *hints;
+
+static BOOL count_only = FALSE;
+static BOOL filenames_only = FALSE;
+static BOOL invert = FALSE;
+static BOOL number = FALSE;
+static BOOL silent = FALSE;
+static BOOL whole_lines = FALSE;
+
+
+
+#if ! HAVE_STRERROR
+/*************************************************
+* Provide strerror() for non-ANSI libraries *
+*************************************************/
+
+/* Some old-fashioned systems still around (e.g. SunOS4) don't have strerror()
+in their libraries, but can provide the same facility by this simple
+alternative function. */
+
+extern int sys_nerr;
+extern char *sys_errlist[];
+
+char *
+strerror(int n)
+{
+if (n < 0 || n >= sys_nerr) return "unknown error number";
+return sys_errlist[n];
+}
+#endif /* HAVE_STRERROR */
+
+
+
+/*************************************************
+* Grep an individual file *
+*************************************************/
+
+static int
+pcregrep(FILE *in, char *name)
+{
+int rc = 1;
+int linenumber = 0;
+int count = 0;
+int offsets[99];
+char buffer[BUFSIZ];
+
+while (fgets(buffer, sizeof(buffer), in) != NULL)
+ {
+ BOOL match;
+ int length = (int)strlen(buffer);
+ if (length > 0 && buffer[length-1] == '\n') buffer[--length] = 0;
+ linenumber++;
+
+ match = pcre_exec(pattern, hints, buffer, length, 0, 0, offsets, 99) >= 0;
+ if (match && whole_lines && offsets[1] != length) match = FALSE;
+
+ if (match != invert)
+ {
+ if (count_only) count++;
+
+ else if (filenames_only)
+ {
+ fprintf(stdout, "%s\n", (name == NULL)? "<stdin>" : name);
+ return 0;
+ }
+
+ else if (silent) return 0;
+
+ else
+ {
+ if (name != NULL) fprintf(stdout, "%s:", name);
+ if (number) fprintf(stdout, "%d:", linenumber);
+ fprintf(stdout, "%s\n", buffer);
+ }
+
+ rc = 0;
+ }
+ }
+
+if (count_only)
+ {
+ if (name != NULL) fprintf(stdout, "%s:", name);
+ fprintf(stdout, "%d\n", count);
+ }
+
+return rc;
+}
+
+
+
+
+/*************************************************
+* Usage function *
+*************************************************/
+
+static int
+usage(int rc)
+{
+fprintf(stderr, "Usage: pcregrep [-Vchilnsvx] pattern [file] ...\n");
+return rc;
+}
+
+
+
+
+/*************************************************
+* Main program *
+*************************************************/
+
+int
+main(int argc, char **argv)
+{
+int i;
+int rc = 1;
+int options = 0;
+int errptr;
+const char *error;
+BOOL filenames = TRUE;
+
+/* Process the options */
+
+for (i = 1; i < argc; i++)
+ {
+ char *s;
+ if (argv[i][0] != '-') break;
+ s = argv[i] + 1;
+ while (*s != 0)
+ {
+ switch (*s++)
+ {
+ case 'c': count_only = TRUE; break;
+ case 'h': filenames = FALSE; break;
+ case 'i': options |= PCRE_CASELESS; break;
+ case 'l': filenames_only = TRUE;
+ case 'n': number = TRUE; break;
+ case 's': silent = TRUE; break;
+ case 'v': invert = TRUE; break;
+ case 'x': whole_lines = TRUE; options |= PCRE_ANCHORED; break;
+
+ case 'V':
+ fprintf(stderr, "PCRE version %s\n", pcre_version());
+ break;
+
+ default:
+ fprintf(stderr, "pcregrep: unknown option %c\n", s[-1]);
+ return usage(2);
+ }
+ }
+ }
+
+/* There must be at least a regexp argument */
+
+if (i >= argc) return usage(0);
+
+/* Compile the regular expression. */
+
+pattern = pcre_compile(argv[i++], options, &error, &errptr, NULL);
+if (pattern == NULL)
+ {
+ fprintf(stderr, "pcregrep: error in regex at offset %d: %s\n", errptr, error);
+ return 2;
+ }
+
+/* Study the regular expression, as we will be running it may times */
+
+hints = pcre_study(pattern, 0, &error);
+if (error != NULL)
+ {
+ fprintf(stderr, "pcregrep: error while studing regex: %s\n", error);
+ return 2;
+ }
+
+/* If there are no further arguments, do the business on stdin and exit */
+
+if (i >= argc) return pcregrep(stdin, NULL);
+
+/* Otherwise, work through the remaining arguments as files. If there is only
+one, don't give its name on the output. */
+
+if (i == argc - 1) filenames = FALSE;
+if (filenames_only) filenames = TRUE;
+
+for (; i < argc; i++)
+ {
+ FILE *in = fopen(argv[i], "r");
+ if (in == NULL)
+ {
+ fprintf(stderr, "%s: failed to open: %s\n", argv[i], strerror(errno));
+ rc = 2;
+ }
+ else
+ {
+ int frc = pcregrep(in, filenames? argv[i] : NULL);
+ if (frc == 0 && rc == 1) rc = 0;
+ fclose(in);
+ }
+ }
+
+return rc;
+}
+
+/* End */