C-check-patch

Step 1 : Download checkpatch.pl from this link - checkpatch_link

Step 2 : Add executable permission to checkpatch.pl
sudo chmod +x ./checkpatch.pl

Step 3 : Create a sample.c

#include<stdio.h> #include<string.h> #include<stdlib.h> #define MIN 2 #define MAX 10 #define MEM_SIZE 8 #define REALLC_S 12 #define DATA_S 20 #define ARR_S 3 #define FOUR 4 void test_1() { char *str = "Hello world!"; char ch = 'l'; char *pos; /*strchr*/ if (pos = strchr(str, ch)) { printf("'%c' is found at pos '%ld' in string \"%s\"\n", ch, pos-str, str); } else { printf("The char %c Not found in \"%s\"\n", ch, str); } } void test_2(){ char *str="Hello world!\0"; char ch='l'; char *ptr=&ch; char *pos= strchr("Hello world!\0",*ptr); printf("%ld\n",pos-str); } void test_3(){ char *p,*k,**q; char a[DATA_S]="bangaloreo"; char b='o'; k=&b; p=&a[0]; q=&p; char *v=strchr(*q,*k); printf("%ld\n",v-a); }

Step 4 : Run checkpatch.pl on sample.c program
sudo ./checkpatch.pl --no-tree -f sample.c

Step 5 : Errors/Warnings from checkpatch.pl

ERROR: Bad function definition - void test_1() should probably be void test_1(void) #12: FILE: b.c:12: +void test_1() ERROR: code indent should use tabs where possible #14: FILE: b.c:14: + char *str = "Hello world!";$ WARNING: please, no spaces at the start of a line #14: FILE: b.c:14: + char *str = "Hello world!";$ ERROR: code indent should use tabs where possible #16: FILE: b.c:16: + char ch = 'l';$ WARNING: please, no spaces at the start of a line #16: FILE: b.c:16: + char ch = 'l';$ ERROR: code indent should use tabs where possible #18: FILE: b.c:18: + char *pos;$ WARNING: please, no spaces at the start of a line #18: FILE: b.c:18: + char *pos;$ ERROR: code indent should use tabs where possible #21: FILE: b.c:21: + /*strchr*/$ ERROR: code indent should use tabs where possible #22: FILE: b.c:22: + if (pos = strchr(str, ch)) {$ WARNING: please, no spaces at the start of a line #22: FILE: b.c:22: + if (pos = strchr(str, ch)) {$ ERROR: do not use assignment in if condition #22: FILE: b.c:22: + if (pos = strchr(str, ch)) { ERROR: code indent should use tabs where possible #23: FILE: b.c:23: + printf("'%c' is found at pos '%ld' in string \"%s\"\n",$ WARNING: please, no spaces at the start of a line #23: FILE: b.c:23: + printf("'%c' is found at pos '%ld' in string \"%s\"\n",$ ERROR: code indent should use tabs where possible #24: FILE: b.c:24: + ch, pos-str, str);$ WARNING: please, no spaces at the start of a line #24: FILE: b.c:24: + ch, pos-str, str);$ ERROR: code indent should use tabs where possible #25: FILE: b.c:25: + } else {$ WARNING: please, no spaces at the start of a line #25: FILE: b.c:25: + } else {$ ERROR: code indent should use tabs where possible #26: FILE: b.c:26: + printf("The char %c Not found in \"%s\"\n", ch, str);$ WARNING: please, no spaces at the start of a line #26: FILE: b.c:26: + printf("The char %c Not found in \"%s\"\n", ch, str);$ ERROR: code indent should use tabs where possible #27: FILE: b.c:27: + }$ WARNING: please, no spaces at the start of a line #27: FILE: b.c:27: + }$ ERROR: Bad function definition - void test_2() should probably be void test_2(void) #30: FILE: b.c:30: +void test_2(){ ERROR: open brace '{' following function definitions go on the next line #30: FILE: b.c:30: +void test_2(){ ERROR: space required before the open brace '{' #30: FILE: b.c:30: +void test_2(){ ERROR: spaces required around that '=' (ctx:VxV) #32: FILE: b.c:32: + char *str="Hello world!\0"; ^ ERROR: spaces required around that '=' (ctx:VxV) #34: FILE: b.c:34: + char ch='l'; ^ ERROR: spaces required around that '=' (ctx:VxO) #36: FILE: b.c:36: + char *ptr=&ch; ^ ERROR: space required before that '&' (ctx:OxV) #36: FILE: b.c:36: + char *ptr=&ch; ^ ERROR: spaces required around that '=' (ctx:VxW) #38: FILE: b.c:38: + char *pos= strchr("Hello world!\0",*ptr); ^ ERROR: space required after that ',' (ctx:VxO) #38: FILE: b.c:38: + char *pos= strchr("Hello world!\0",*ptr); ^ ERROR: space required before that '*' (ctx:OxV) #38: FILE: b.c:38: + char *pos= strchr("Hello world!\0",*ptr); ^ ERROR: space required after that ',' (ctx:VxV) #40: FILE: b.c:40: + printf("%ld\n",pos-str); ^ ERROR: Bad function definition - void test_3() should probably be void test_3(void) #43: FILE: b.c:43: +void test_3(){ ERROR: open brace '{' following function definitions go on the next line #43: FILE: b.c:43: +void test_3(){ ERROR: space required before the open brace '{' #43: FILE: b.c:43: +void test_3(){ ERROR: space required after that ',' (ctx:VxO) #45: FILE: b.c:45: + char *p,*k,**q; ^ ERROR: space required before that '*' (ctx:OxV) #45: FILE: b.c:45: + char *p,*k,**q; ^ ERROR: space required after that ',' (ctx:VxO) #45: FILE: b.c:45: + char *p,*k,**q; ^ ERROR: space required before that '*' (ctx:OxO) #45: FILE: b.c:45: + char *p,*k,**q; ^ ERROR: spaces required around that '=' (ctx:VxV) #47: FILE: b.c:47: + char a[DATA_S]="bangaloreo"; ^ ERROR: spaces required around that '=' (ctx:VxV) #49: FILE: b.c:49: + char b='o'; ^ ERROR: spaces required around that '=' (ctx:VxO) #51: FILE: b.c:51: + k=&b; ^ ERROR: space required before that '&' (ctx:OxV) #51: FILE: b.c:51: + k=&b; ^ ERROR: spaces required around that '=' (ctx:VxO) #52: FILE: b.c:52: + p=&a[0]; ^ ERROR: space required before that '&' (ctx:OxV) #52: FILE: b.c:52: + p=&a[0]; ^ ERROR: spaces required around that '=' (ctx:VxO) #53: FILE: b.c:53: + q=&p; ^ ERROR: space required before that '&' (ctx:OxV) #53: FILE: b.c:53: + q=&p; ^ ERROR: spaces required around that '=' (ctx:VxV) #55: FILE: b.c:55: + char *v=strchr(*q,*k); ^ ERROR: space required after that ',' (ctx:VxO) #55: FILE: b.c:55: + char *v=strchr(*q,*k); ^ ERROR: space required before that '*' (ctx:OxV) #55: FILE: b.c:55: + char *v=strchr(*q,*k); ^ ERROR: space required after that ',' (ctx:VxV) #57: FILE: b.c:57: + printf("%ld\n",v-a); ^ total: 42 errors, 10 warnings, 59 lines checked NOTE: For some of the reported defects, checkpatch may be able to mechanically convert to the typical style using --fix or --fix-inplace. NOTE: Whitespace errors detected. You may wish to use scripts/cleanpatch or scripts/cleanfile b.c has style problems, please review. NOTE: If any of the errors are false positives, please report them to the maintainer, see CHECKPATCH in MAINTAINERS.

Step 6 : Clear all Errors/Warnings and repeat from Step 4