44 * the standard input. Should the file name be printed when a matching line is
55 * found?
66 *
7- * Answer: of course!
8- *
97 * By Faisal Saadatmand
108 */
119
10+ /* Answer: only when files are named as arguments */
11+ 1212#include <stdio.h>
13- #include <string.h>
1413#include <stdlib.h>
14+ #include <string.h>
1515
16- #define MAXLINE 1000
16+ #define MAXLEN 1000
1717
1818/* globals */
19- char * progName ;
19+ char * prog ; /* program name */
2020
2121/* functions */
2222int getLine (char * , size_t , FILE * );
2323FILE * loadFile (char * );
24- int findPattern (FILE * , char * , char * , int , int );
24+ int findPattern (FILE * , const char * , const char * , const int ,const int );
2525
2626/* getLine: read line, return length - file pointer version */
2727int getLine (char * line , size_t max , FILE * fp )
@@ -35,38 +35,44 @@ FILE* loadFile(char *fileName)
3535{
3636 FILE * fp ;
3737 if (!(fp = fopen (fileName , "r" ))) {
38- fprintf (stderr , "%s: can't open %s\n" , progName , fileName );
38+ fprintf (stderr , "%s: can't open %s\n" , prog , fileName );
3939 exit (EXIT_FAILURE );
4040 }
4141 return fp ;
4242}
4343
44- int findPattern (FILE * fp , char * fileName , char * pattern , int except , int number )
44+ int findPattern (FILE * fp , const char * fileName , const char * pattern ,
45+ const int except , const int number )
4546{
46- char line [MAXLINE ];
47- long int lineno , found = 0 ;
47+ char line [MAXLEN ];
48+ long lineno ;
49+ int found ;
4850
49- for (lineno = 1 ; getLine (line , MAXLINE , fp ) > 0 ; lineno ++ )
51+ lineno = found = 0 ;
52+ while (getLine (line , MAXLEN , fp ) > 0 ) {
53+ ++ lineno ;
5054 if ((strstr (line , pattern ) != NULL ) != except ) {
5155 if (fileName )
52- printf ( "%s:" , fileName );
56+ fprintf ( stdout , "%s:" , fileName );
5357 if (number )
54- printf ( "%ld:" , lineno );
55- printf ( "%s" , line );
56- found ++ ;
58+ fprintf ( stdout , "%ld:" , lineno );
59+ fprintf ( stdout , "%s" , line );
60+ ++ found ;
5761 }
62+ }
5863 return found ;
5964}
6065
6166/* find: print lines that match pattern from 1s arg */
6267int main (int argc , char * argv [])
6368{
64- int c , except = 0 , number = 0 , found = 0 ;
65- char * pattern = NULL ;
66- FILE * file = NULL ;
69+ int c , except , number , found ;
70+ char * pattern ;
71+ FILE * file ;
6772
68- progName = argv [0 ];
69- while (-- argc > 0 && (* ++ argv )[0 ] == '-' ) /* check for flags */
73+ prog = argv [0 ];
74+ except = number = found = 0 ;
75+ while (-- argc > 0 && (* ++ argv )[0 ] == '-' ) /* check for flags */
7076 while ((c = * ++ argv [0 ]))
7177 switch (c ) {
7278 case 'x' :
@@ -76,20 +82,19 @@ int main(int argc, char *argv[])
7682 number = 1 ;
7783 break ;
7884 default :
79- printf ( "%s: illegal option %c\n" , progName , c );
85+ fprintf ( stderr , "%s: illegal option %c\n" , prog , c );
8086 argc = 0 ;
8187 found = -1 ;
8288 break ;
8389 }
84- 85- pattern = * argv ; /* save a pointer to the pattern */
90+ pattern = * argv ++ ; /* save a pointer to the pattern */
8691 if (argc < 1 )
87- printf ( "Usage: %s -x -n pattern \n" , progName );
88- else if (argc == 1 ) /* input from stdin */
92+ fprintf ( stderr , "Usage: %s [-xn] PATTERN [FILE...] \n" , prog );
93+ else if (argc == 1 ) /* input from stdin */
8994 found += findPattern (stdin , NULL , pattern , except , number );
90- else /* input from file or set of files */
95+ else /* input from file or set of files */
9196 while (argc -- > 1 ) {
92- file = loadFile (* ++ argv );
97+ file = loadFile (* argv ++ );
9398 found += findPattern (file , * argv , pattern , except , number );
9499 fclose (file );
95100 }
0 commit comments