Compilare: user.c: In function ‘main’: user.c:25:5: warning: implicit declaration of function ‘strlen’ [-Wimplicit-function-declaration] {for(i=0;i<strlen(s);i++) {{if(s[i]==':') {i+=2;while(!((s[i]>='a'&&s[i]<='z')||(s[i]>='A'&&s[i]<='Z')||(s[i]>='0'&&s[i]<='9')))i++; ^ user.c:25:16: warning: incompatible implicit declaration of built-in function ‘strlen’ [enabled by default] {for(i=0;i<strlen(s);i++) {{if(s[i]==':') {i+=2;while(!((s[i]>='a'&&s[i]<='z')||(s[i]>='A'&&s[i]<='Z')||(s[i]>='0'&&s[i]<='9')))i++; ^ user.c:5:14: warning: unused variable ‘m’ [-Wunused-variable] int i,j,n=-1,m; ^ user.c:10:7: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%c",&c); ^ user.c:11:42: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] while(c!='}') {if(c=='{'||c==',') {fscanf(f,"%c",&c); printf("%c ",c);while(!(c>='a' && c<='z')||(c>='A'&& c<='Z')||(c>='0'&&c<='9')) fscanf(f,"%c",&c);fseek(g,n+1,0); ^ user.c:11:141: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] while(c!='}') {if(c=='{'||c==',') {fscanf(f,"%c",&c); printf("%c ",c);while(!(c>='a' && c<='z')||(c>='A'&& c<='Z')||(c>='0'&&c<='9')) fscanf(f,"%c",&c);fseek(g,n+1,0); ^ user.c:12:78: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] n++;while(c!='"') {fprintf(g,"%c",c);fscanf(f,"%c",&c);n++;} ^ user.c:14:41: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%c",&c); ^ user.c:15:35: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] while(c==' ') fscanf(f,"%c",&c);//printf("%c ",c); ^ user.c:21:10: warning: ignoring return value of ‘fgets’, declared with attribute warn_unused_result [-Wunused-result] fgets(s,100,f); ^ user.c:31:10: warning: ignoring return value of ‘fgets’, declared with attribute warn_unused_result [-Wunused-result] fgets(s,100,f); ^