Question

Suppose I have file which goes like this :

      a  void measure()    
         {

      a  GPIOPinTypeADC(GPIO_PORTE_BASE, GPIO_PIN_7); // Pin assignment
         ADCSequenceConfigure(ADC0_BASE, 3, ADC_TRIGGER_PROCESSOR, 0);
         appended line for demonstration
         ADCSequenceStepConfigure(ADC0_BASE, 3, 0, ADC_CTL_CH0 | ADC_CTL_IE |ADC_CTL_END);
         ADCSequenceEnable(ADC0_BASE, 3);//sample sequence 3 is enabled.
         ADCIntClear(ADC0_BASE, 3);   // Clear the interrupt status flag.
         }

Can I use SED or AWK to output true if and only if a is prepended to the first coloum with space as the delimiter . The first character is always a otherwise space .

As of now I use GREP :

    if grep -q "^a" file.c; then
       echo "The file is prepended"
       else
       echo "the file is clean"
   fi

I have several functions like the first one above in separate files and want to categorise it based on the prepended a .

Is it possible to do this easily and over multiple files using GREP itself .I would really prefer a SED or AWK alternative avoiding the use of the if construct for hundreds to come .

Suggestions or better algorithms are always welcome 🙂

Answer 1

It’s very difficult to tell what you’re asking, but it sounds like you might want this

grep -q ^a file.c && echo 'The file is appended' || echo 'the file is clean'

Or perhaps you really want this:

grep -L ^a *.c

Each resulting file name being an “appended” file.

For multiple files you could do it this way

for file in *.c ; do
   grep -q '^a ' file.c && echo 'The file is appended' || echo 'the file is clean'
done

For multiple files recursively, try

find . -type f -name '*.c' -exec grep -q '^a ' {} \; -print

Although to get the ‘correct’ output you’d need more work.