Sams Teach Yourself C in 21 Days

624 Week 3

196: * Function: look_up()

197: * Returns: Number of names matched

198: *************************************************/

199:

200: int look_up( FILE *fp )

201: {

202: char tmp_lname[20+1];

203: int ctr = 0;

204:

205: fprintf(stdout, “\n\nPlease enter last name to be found: “);

206: gets(tmp_lname);

207:

CH 17 208: if( strlen(tmp_lname) != 0 )

209: {

CH 16 210: if (fseek( fp, 0, SEEK_SET ) == 0)

211: {

CH 16 212: fread(&rec, 1, sizeof(rec), fp);

213: while( !feof(fp))

214: {

CH 17 215: if( strcmp(rec.lname, tmp_lname) == 0 )

216: /* if matched */

217: {

218: fprintf(stdout, “\n%s %s %s - %s”, rec.fname,

219: rec.mname,

220: rec.lname,

221: rec.phone);

222: ctr++;

223: }

224: fread(&rec, 1, sizeof(rec), fp);

225: }

226: }

227: fprintf( stdout, “\n\n%d names matched.”, ctr );

228: }

229: else

230: {

231: fprintf( stdout, “\nNo name entered.” );

232: }

233: return(ctr);

234: }

LISTINGR3.1 continued

This program is similar in some respects to the programs presented in Week 1 in

Review and Week 2 in Review. Fewer data items are tracked, but additional pro-

gram capabilities have been added. week3.c lets the user keep track of names and phone

numbers of friends, business contacts, and so on. As written, the program tracks only

first name, last name, middle name, and phone number. It would be a simple matter to

have the program record additional information, and you might want to try this as an

exercise. The major difference between this program and the earlier review programs is

ANALYSIS

34 448201x-W3R 8/13/02 11:22 AM Page 624